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View Full Version : The truth about high-resolution audio compared with std. CD 44k?



HUG-1
29-05-2011, 09:22 PM
This thread is concerned with audio delivery formats and ripping.

QChicago
30-05-2011, 08:20 PM
This is somewhat of a complex subject because, as I see (hear) it, there are several factors that appear to affect SQ, whether the recording is 44.1/16 or higher. All of my music is sourced from a computer (Mac Mini). It is either ripped in AIFF format from CDs (44.1/16) or downloaded from Linn Records of HD Tracks ("hi-rez").

1. In my limited experience, I have found that the quality of the recording is first and foremost. I have 44.1/16 rips that sound stunning, and others that sound lacking to downright poor. Some of this, IMO, depends on the type of music. For example, recordings such as acoustic guitar, vocals, and the like, sound magical because they take advantage of the mid-range capabilities of my Super HL5s. That being said, I have rock rips that also sound terrific and I owe that mainly to the recordings.

2. I have an HD Tracks download (rock) at 96/24. IMO, the quality is poor and muddy. Many of my CD rock rips sound vastly superior at 44.1/16.

3. I have a studio master 192/24 download from Linn (classical violin / orchestra), which sounds amazing.

4. Whether there is any noticeable SQ difference between FLAC, AIFF, Lossless and WAV is dubious. I have read comments that claim a difference. My take is that there is little if any audible difference. As long as the rip is bit accurate and MP3 or like is avoided, I believe no one really hears a difference.

GregD
31-05-2011, 12:13 AM
I think seeing a "96/24" or "DSD" icon light-up on your disc player/DAC can give a nice reassuring hi-rez feeling that can make the music "seem" better. Whether it IS audibly better or not, I don't know.

I "seem" to enjoy SACDs on my new dCS player more than any other previous SACD player I've owned and usually more so than the CD versions.

Alan showed a while back how filtered recordings of a solo violin sounded no different with several kHz cut-off the top of the frequency range. However, I continue to buy SACDs whenever I can, in preference to CDs because it justs feels like a more relaxed, freer sound with better musical flow and detail. Maybe the SACD logo has an effect on my brain's pleasure centres and my brain has ended-up associating the logo with feeling good (marketing?), leading to me preference the "sound" of SACD?

Whether it's real or imagined, I definitely like SACD more than CD!

QChicago
31-05-2011, 11:34 PM
If you haven't already, (just for fun) you might try "testing" one with the other on yourself and others and see if anyone can tell the difference. Again, I would not be surprised if certain CDs sound as good or even better than certain SACDs due to the nature of the music and/or the quality of the recording.

GregD
24-06-2011, 08:37 PM
If you haven't already, (just for fun) you might try "testing" one with the other on yourself and others and see if anyone can tell the difference. Again, I would not be surprised if certain CDs sound as good or even better than certain SACDs due to the nature of the music and/or the quality of the recording.

I have done quite a few times. Audio civilians always prefer the SACD layer, 100% of the time. And they had never heard of SACD or DSD until I told them and had no technical knowledge of electronics/loudspeakers.

hifi_dave
25-06-2011, 11:07 AM
I've done the CD v SACD comparison several times for customers, using very expensive machines like Esoteric and Ayre but with different results. On each occasion, with all types of music, the customers have preferred the ( less expensive ) CD player !!!

Pluto
28-06-2011, 10:03 PM
...that I can convert any hi-res material down to 16/44 and, under blind conditions, you will not be able to tell them apart with any kind of statistically valid consistency.

Any takers?

Labarum
28-06-2011, 11:33 PM
Not me.

Take it down further to 256 kb/s AAC or OGG or WMA or even MP3 and it would still be extremely difficult to tell.

A.S.
29-06-2011, 10:26 AM
...that I can convert any hi-res material down to 16/44 and, under blind conditions, you will not be able to tell them apart with any kind of statistically valid consistency.

Any takers?OK, I'm up for this. Although I have my preconceptions. It would be nice if we could paste the links into your post on this thread. But that would mean all examples would have to be MP3 format. I'm not sure if the MP3 bitrate or sampling rate is fixed here on HUG for the embedded player, but I suppose 48k 320kB (or more?) may conceivably play. Thus far, all MP3s have been at 44k. Worth a try?

Labarum
29-06-2011, 10:51 AM
Aren't there two issues here?

1. That once above CD quality of 16/44.1 it would be difficult to hear any difference at higher definition (say 24/96). To test that either WAW files of losslessly compressed files (say ALAC or FLAC) would have to made available. As soon as you recode to a lossy format like MP3 you would be testing something else:

2. That once above a certain compression bitrate (say 256 kb/s) no difference could be heard between the parent file and its digitally compressed child.

Test 2. has been done. See

http://www.harbeth.co.uk/usergroup/showthread.php?1149-Lossless-or-not-Lossless-compression-...&highlight=labarum

or

http://www.audiosmile.com/forum/showthread.php?t=25890

Test 1. could be tried using sample files available here

http://www.gimell.com/catalogue.aspx?filter=Studio+Master

It is possible to hear free samples of these recordings at 16/44.1 and higher.

{Moderator's comment: Yes. But we have no other way of presenting side by side clips here on the HUG *unless* we use the inbuilt Mp3 player.

kittykat
29-06-2011, 11:24 AM
[QUOTE=Pluto;15062 Any takers?[/QUOTE]

Perhaps someone would like to invite this (lady?) ...

http://audioiconoclast.blogspot.com/

the best hobbies should be left to men ;-0

Pluto
29-06-2011, 11:51 AM
I suspect that any attempt to play anything via the HUG board software will render any test invalid; it has to be files that you download and play yourself. We can work out the logistics of this after we know how many takers we are dealing with.

One or more of you will need to provide me with some files that you believe to be a top example of the state of the hi-res art. I would suggest no higher than 24/96 as otherwise the data volume becomes huge and quite a lot of kit only functions up to 96kHz. I will convert those files to 16/44 using methods that I will not fully disclose for the time being. I will then (probably) place the converted data within a hi-res wrapper at the same sample rate as the original* and send it either to individuals or for distribution via this board, however we agree to handle the logistics.

There has to be a degree of honesty for this test to be of use because it is always possible to examine the files forensically to determine which is which - at the simplest level, the hi-res stuff will contain programme-related information > 22kHz which a file at a sampling rate of 44.1kHz cannot. The challenge is, can you tell the hi-res material from 16/44 by listening alone.

* The point of the wrapper is to ensure that we are testing only audible differences between the files, not your equipment's ability to play one format better than another.

Labarum
29-06-2011, 12:50 PM
If the HiRes files are 24/96 wouldn't it be more appropriate to make the LoRes files 16/48 rather than 16/44.1? The downsampling is a simpler computational process, and we exclude other possible degradations to the LowRes files.

RobHolt
30-06-2011, 12:43 AM
As the author of the test linked to by Brian (Labarum) I find this an interesting proposition and would like to participate. However I agree with his comment that presenting the samples as MP3 will invalidate the test as you've immediately introduced another very significant variable.

There are some other precautions that need to be taken. The 16/44 data needs to be presented as a 24/96 file so that are visually the same. You also need to consider that the true 24/96 file is likely to have considerable content above 20kHz. Anyone with a file editor can load them up and take a peek. So a great idea so long as there is some basic blind test housekeeping.

I'd say make files available for download by the listener.

Rob.

Pluto
30-06-2011, 01:11 AM
If the HiRes files are 24/96 wouldn't it be more appropriate to make the LoRes files 16/48 rather than 16/44.1?
The whole point of the exercise is that we reduce the hi-res to the lowest common denominator; 16/44.

Pluto
30-06-2011, 07:09 PM
You also need to consider that the true 24/96 file is likely to have considerable content above 20kHz. Anyone with a file editor can load them up and take a peek. So a great idea so long as there is some basic blind test housekeeping
Already considered...read message #12 (http://www.harbeth.co.uk/usergroup/showthread.php?1293-The-truth-about-high-resolution-audio-compared-with-std.-CD-44k&p=15072#post15072) in this thread!

Ultimately, there is nothing we can do to stop people cheating by examining the audio bandwidth within the test files and claiming that "file X definitely sounds worse than file Y". But remember, it's only a game!

Kumar Kane
09-07-2011, 04:00 AM
The last week has been spent in getting digital wireless sound into my reasonably hi fi systems - which are:

1. Marantz SACD Pearl,Quad 99/909,Harbeth Compact 7 - main system
2. Denon M38,Spendor S3/5 se - bedroom

For domestic reasons the latter sits on a long wood desk in the bedroom next to my mac, not the best place for the speakers, but it works quite well for all that, with some vibrapods below the speakers, which are also placed close to the front edge of the desk.

What has been interesting is that my ears can't hear any difference in sound quality, regardless of what I do at the source/cables, as long as that source is free from gross distortion like hum or static.

A list of sources/cables tried, in getting to a stable wifi signal feed, including those tried for comparison reasons.

1. Itunes streaming to Airport Express, connected to the amps via analog wire, and also via optical Toslink
2. Itunes connected via computer headphone socket to aux in of the amp by analog wire.
3. Ipod touch streaming via dock connector to a made for ipod USB socket on the amp.
4. Itunes/mac connected by USB wire to a USB for computer socket on the Marantz.
5. SACD on Marantz.
6. LPs on Rega P5.
7. CDs on Marantz.

It seems that none of these influence the sound to a degree I can hear in my home. And I have now realised that what I do not hear for myself, isn't worth the trouble or the expense. Of course, the sound is hugely different for the same source in the main living room, and in the bedroom - no surprise there, different speakers, different placement, different room acoustics.

QChicago
10-07-2011, 11:38 PM
I'm not surpirsed. I think you've nailed it on the head. Cables need to be decent not exotic / expensive (i.e., they need to be undamaged, of appropriate gauge, and designed satisfactorily to get their jobs done).

Speaker placement and room acoustics are vastly more important IMO and experience.

Kumar Kane
11-07-2011, 10:48 AM
I'm not surpirsed. I think you've nailed it on the head. Cables need to be decent not exotic / expensive (i.e., they need to be undamaged, of appropriate gauge, and designed satisfactorily to get their jobs done).

Speaker placement and room acoustics are vastly more important IMO and experience.

And it isn't just cables. To my ears ( and to the benefit of my wallet!), I also now find that even external DACs are of no audible value. One of things I needed to do in my systems was to connect the mac to the Denon. I was busy researching - which USB DAC is best etc etc - when I thought I should first just run a 8 GBP analog wire from the mac's headphone socket to the RCA aux inputs on the Denon amp. With the mac not injecting any static or hum into the signal, I find that to my ears, it sounds just as good as a CD played in the Denon. There is a reduced volume of sound, I suspect that the current from the mac out is a little lower than usual, but the denon amp has enough head room for my needs in the room to take care of that. It is once that is done that I do not realise the difference between the two sources of course. Another feature of this connection is that the volume can be controlled at the mac as well, though this has its downsides as well.

I believe that there are products in the market that are sold for improving this mac to amp connection, for prices ranging from 200 GBP to 10000 GBP. Exotic cables apart! I could never afford the 10000 GBP stuff, but before I became a member , and read about this subject in some detail here, I would have put down up to 400-500 GBP for this, including for the two different kinds of cables needed...so it is good to not have golden ears?!!:-)

I also realise that there may some computers that will inject electrical noise into the signal from the headphone output socket, but these would be the exception I should think. After all, if they did that, it would be heard on headphones as well, rendering that socket pretty much useless.

Diminish
11-10-2011, 11:15 PM
Last evening I read an interesting passage on the operation of a CD transport. I am reading Robert Harley's "The Complete Guide to High End Audio" concurrent with "Principles of Digital Audio", Ken Pohlman's definitive text on the subject. My purpose in doing this is to gain a better fundamental understanding of digital audio playback. The fact that music's passion, drive, perspective, and expression can be captured in a stream of one's and zero's, I find absolutely fascinating.

Prior to this study, I thought that the DAC section in a CD player was the real workhorse; responsible for the majority of processing. It turns out that this is not the case at all. The transport does a lot more than just shine a laser beam on a spinning disc! First of all, the data contained on a CD is not in the familiar SPDIF format. It is stored in what's called EFM or "Eight to Fourteen Modulation". Here, a 8 bit blocks are assigned 14 bit words along with merging bits which are responsible for the data stream. This stream contains not only the audio data, but also the clock signal, table of contents, and error correction data. Pits and Lands are embedded in the optical disc. Both of these result in a binary zero, while the transition from pit to land (or vice versa) correlates to a binary one. A device called an optical decoder divides the audio info, from the subcode and reads and interprets these bits.

Another assumption that I would have made prior to this reading was that, much like a turntable, the data was read at the exact instant it was converted. This is not so, a certain amount of buffering has to be implemented so that error correction can work properly. This is not to suggest that disc rotation is not precisely controlled; the transport's servo allows for very high degrees of precision. The optical signal coming off the disc is very analog in nature. After all the information is extracted, de-interleaved, and decoded; the end result is the familiar SPDIF bitstream and a clock signal.

Due to the great complexity of a CD transport, I am convinced that they would account for many of the audible differences heard between various CD players. Another interesting conclusion that is supported by Mr. Harley is that bypassing a transport altogether, and having a computer read the SPDIF data, can result in a more accurate analog output. This is a big advantage music servers have over disc players.

Since this thread is concerned with digital playback and differences among formats, I thought I would post here. The first 16 entries of the thread seemed to be leading up to an objective comparison of audio files. Then, we got back to the ongoing cable debate. It appears that some such test were already performed with less than definitive results. Even if the testing were to proceed with the most stringent possible regulation, I am doubtful that any objective conclusion would be reached. In a very general sense, it makes sense that more information would translate to better sound quality.

Lossy compression algorithms have shown that certain information is more musically relevant. A 128Kbs Mp3 stream has less than 1/10th the bit-rate of Redbook CD, yet it does come fairly close to representing the original. Does it sound 10 times worse than Redbook? Would a 256Kbs stream sound twice as good? Does a 24/176 file, recorded at this sample and bit rate, sound 6 times better than CD? Well, I think we've crossed over from an objective to a subjective response with this. I also think there is something very similar to Economic's Law of Diminishing Returns at work. For example, I enjoy listening to Linn Radio which is a 320Kbs stream. This is roughly a quarter of the data rate for CD, but it is considered "Hi-Res" by streaming standards. For the most part, I don't notice anything lacking in the sound. On the rare occasion that they play something that I own, I will listen to it and then play back my file for comparison. This is not a "blind" test and it only accounts for 2/3 of the ABX process. Lets just say that I have to listen very hard for differences. If they exist at all, its not something that I would be willing to bet on being able to detect. On the other hand, does this mean that I should go ahead and compress my entire Library to save on the space occupied by the bits that I just admitted were of little significance?

Well, maybe, but I'm not going to be doing it, and I wouldn't even if storage were at a premium.

A.S.
12-10-2011, 10:55 AM
Last evening I read an interesting passage on the operation of a CD transport... Due to the great complexity of a CD transport, I am convinced that they would account for many of the audible differences heard between various CD players...Er, no! Have you allowed your preconviction that 'CD players sound different' combined with your abandoned belief that 'DACs sound different' to grasp for a second belief that 'the all important element is the CD mechanism' (I summarise).

There may well be sonic differences between CD players - I'm not listening for them but I don't doubt that something is audible - but you are barking up the wrong tree if you think the CD mechanism is complex and hence, likely to be the source of any differences. The miracle of the CD concept (as I've discussed long ago) is not its complexity but its extreme electro-mechanical simplicity. I repeat - the Sony/Philips designers intentionally, deliberately and wholeheartedly approached the design of the discs and the players with cost minimisation (aka engineering simplicity) at the very top of the design specification. And were they proved right: absolutely. It was a wonderful collaborative effort between European and Japanese engineers who shared different cultural approaches to engineering perfection, but found a solid common ground.

The reason is this: driven (rightly) in the early 1980s by marketing predictions of the likely consumer uptake of audio CDs (billions of discs, tens or hundreds of millions of CD player mechanisms), combined with the persistent and costly returns of mis-pressed LP records by the public, the engineers wanted a completely foolproof 'sell and forget' system. Discs that were (are) cheap to duplicate, indestructible, almost totally immune to even severe scratching and with player mechanisms that would cope with anything thrown at them. And that translated in the engineering design to the CD system's ability to cope with a huge spread of manufacturing tolerances in the discs and mechanism plus likely consumer/environmental degradation (another set of wide tolerances). So they anticipated every imaginable scenario of player and disc edge-of-tolerance: just a little bit too fast or too slow, a fresh laser or a weak one after years of use, dust on the laser, rotational bearing wear leading to non-concentric rotation, bearing oil/grease becoming sticky, laser misalignment laterally and vertically, scratches along and across the disc, disc data pits with fuzzy not sharp edges, flaking reflective CD top layer, likely power supply variation country to country, hour to hour etc. etc. etc.. In microcosm, they 'put a man on the moon and brought him back'.

And what did they conclude? They appreciated that the entire CD player/disc system had to have built-in significant error correction and feedback systems, mechanically and electrically. And these systems themselves had to be robust and reliable, fast acting, completely transparent to the user, automatic, and that the user could not even if he wanted to, 'go manual' and bypass layers upon layers of complex interlinked self-regulating feedback control systems. And that was a genius decision. There could be no tweaking of the transport, no re-writing of the control code, no user controls other than basic play/stop/search and no possibility at all to reinterpret, reinvent or improve upon the transport system devised by the collective genius of the worlds best consumer electronics working across two continents. And that's how it stands today.

And the consequence of superb engineering foresight was that both the discs themselves and the transport mechanisms could be punched out in sweatshop conditions without the need for a super-clean environment, using simple machinery in the hundreds of millions. No need to tweak and adjust every mechanism. Just bash them out and flog them in vast quantities. And that ensured (as Sony/Philips anticipated) that the cost of producing the mechanism would fall to little more than the cost of producing the disc, wholly unlike the LP record and its player mechanism.

Attached is a scan from a current (and rather pricey) trade catalogue listing CD and DVD players for the PC. They sell the mechanism in a tin case to suit a PC, in a nice cardboard box with instructions, screws, audio cable etc.. Item B, cost GBP 12.95 will have a mechanism that is functionally identical to what you'll find in an audio CD system (plus lots of additional features incl. Lightscribe, ability to read and write up to 48x - CD audio is only 1 x). Item D can read BlueRay which is a far, far more complex disk to read and interpret than CD audio. It's cost, GBP 42.95. From this I suppose we can assume that the cost of the mechanism itself, made in China, can be no more than a few dollars.

And as for 'jitter'; the implications of that certain inevitability was fully considered by the Sony/Philips designers who built-in perfectly adequate and completely robust correction systems to guarantee that it just would not be an issue at all for the consumer.

>

Pluto
12-10-2011, 11:51 AM
...states that if the data is recoverable, the sound of a digital audio system is entirely dependent upon the quality of the converter sub-systems at either end of the process.

This means that nothing happening between the two converters has any bearing at all on the sound quality, provided that the data remains 100% recoverable.

Discuss....

Kumar Kane
12-10-2011, 12:34 PM
There could be no tweaking of the transport, no re-writing of the control code, no user controls other than basic play/stop/search and no possibility at all to reinterpret, reinvent or improve upon the collective genius of the worlds best consumer electronics working across two continents. And that's how it stands today.
>
A question, based on the above.

From all one reads, there is a vast difference in the audio quality between the first generation of CD players from a couple of decades ago, and those of today - which themselves are sold at prices ranging from around GBP 50 to GBP 2500 or more.

Is there anyone that has done an ABX comparison of the sound from the three types referred to above, played through a set of speakers like Harbeths/others in that category? By three, I mean a first generation CD player and two from different ends of the price ranges of today.

I ask the question because I have read so much about how the current generation of CD players, even the budget end, are so very improved from those in the early days of CDs, which sounded sterile, flat, or whatever other audiophile expletives can be used to describe them.

Or is this another example of high end audio marketing hype?

HUG-1
12-10-2011, 06:26 PM
...Or is this another example of high end audio marketing hype?To be fair ... the present global economic system shows what happens when people stop believing the marketing hype. They don't spend money. What is better? Going along with the BS only half expecting total satisfaction or the economic stagnation of not spending money at all?

Kumar Kane
12-10-2011, 06:47 PM
To be fair ... the present global economic system shows what happens when people stop believing the marketing hype. They don't spend money. What is better? Going along with the BS only half expecting total satisfaction or the economic stagnation of not spending money at all?
Long term it is certainly better in my opinion to not spend the money chasing rainbows. Yes, there will be a lot of pain while the system self corrects, but given the people v natural resources imbalance, that would the most sustainable way forward for humanity.

That said, and human nature being what it is, I don't see that disbelief in marketing hype will last for long...pity.

Pluto
12-10-2011, 07:08 PM
...the present global economic system shows what happens when people stop believing the marketing hype...
I hardly think that the present global economic position is down to people no longer buying overpriced CD players! But I do believe that, in the UK at any rate, the overall loss of interest in decent domestic audio is, in significant measure, due to the 'loony toons' approach to marketing. 'Audiophile' has become a byword for a nutter who spends £100 on a cable on which 'normal' people spend £1. Or one who plays vinyl when the world has largely moved to iPods.

Those (consumer research people) who advise manufacturers have driven domestic products into ever more stratospheric regions and come up with the hype to promote them. The reality is that there haven't been any truly significant developments, particularly in analogue design, for the last twenty years. There are very few instances of a state of the art analogue product of twenty years ago not remaining entirely satisfactory today.

Cyreg
12-10-2011, 08:01 PM
Just a very general observation/opinion triggered by this thread.

C'mon, just a little more time and at Harbeth's you're gone tell us that all LP cartridges sound the same!
And that it doesn't matter at all in whatever turntable and arm and on what surface.
Because we do play the same LP grooves > but here we "can explain?" that there's also a lot of mechanics involved

Not all sounddifferences can be explained nor ignored just by finding technical explications, as far(little) as we now know!

Also the speakerstands, powercables, loudspeakercable and interconnects or combination's should sound all alike according to Harbeth's with very little sounddifferences.

40 years ago general opinion was that all amplifiers with (than known specs!!) should sound the same, and......?
.....even the amp.housing proved to be of influence on the sound

I believe in Harbeth's sound and designs and so do a lot of people....and
....guess what > lot of technics, but "for us" no specs, but finetuned by a trained ear for the right sound and trust in it.

No, IMO there are a lot of different sounding electronics, interfaces and combinations and much different pricing.
You don't have to steal the bank, but you'll have to find your own Walhalla against your costprice!

EricW
12-10-2011, 09:09 PM
To be fair ... the present global economic system shows what happens when people stop believing the marketing hype. They don't spend money. ...

If only I believed it were actually a matter of choice ...

People aren't spending money because they have no money (or much less money) to spend. It's that simple. The reasons why this is so are manifold and complex, but the effect is simple. When your ability to spend is restricted, you tend to focus on what's essential and cut the frills. Not surprising.

However, I don't think a change in economic circumstances has changed human nature. If we turn the corner on the current worldwide economic problems, I think things will be the same as they ever where. The fundamental question is whether we are now at a point where it's simply no longer possible to live a life based on unlimited consumption on a planet with limited and finite natural resources.

Diminish
12-10-2011, 10:10 PM
"Er, no! Have you allowed your preconviction that 'CD players sound different' combined with your abandoned belief that 'DACs sound different' to grasp for a second belief that 'the all important element is the CD mechanism' (I summarise)."

Was this intended as a question? I have to continually remind myself that this is the HUG, albeit the "your views, not Harbeth's" section. The notion that CD players sound different is more of an axiom to me than something requiring proof and open to debate. If the above quote was intended as a question, please allow me to point out that I have not abandoned my belief that DAC's sound different. I was re-evaluating my view of the transport's contribution to the audible difference between players. You state that "The miracle of the CD concept (as I've discussed long ago) is not its complexity but its extreme electro-mechanical simplicity." Prior to this reading, I thought that the transport was SPDIF in, SPDIF out; basically just converting optical data to electronic. I was unaware of the EFM code, interveavened data, Reed-Solomon Code, and error correction that takes place prior to the generation of a SPDIF bitstream. I'm not putting it up there with the Human Genome Project, but to a layman such as myself; a CD transport is rather complex. The fact that it is an electro-mechanical process, and not simply electronic, would suggest complexity greater than that of a DAC. There is also an optical component to a transport, and data is subject to more processing in the transport than the DAC. Complexity is defined as "being characterized by a highly involved arrangement of parts, units, ect." I think that a transport meets this qualification. In fact, HUG-1, goes on to discuss the "layers upon layers of complex interlinked self-regulating feedback control systems" incorporated in a CD transport.

Just because something is complex does not mean it is inaccurate, in fact, transports are designed for accuracy, precision, predictability, and replicability. Paradoxically, added complexity also invites a greater potential for error. This is what I was focusing on when I asserted that transports could have a greater impact on a CD player's sound quality. Bypassing a transport altogether and playing files from a computer's hard drive in their SPDIF format can and does result in improved sound quality. This view is integral to the music server and computer audio industry, and it is one where I'm in very good company. It might also be noteworthy in discussing the drop in sales of CD players.

{Moderator's comment: factually, CD transports are elegantly simple devices. Have you looked inside one? You just can't get simpler than a motor, a spindle and a laser arm and a little processing logic. Would you like us to disassemble one to show you?}

A.S.
13-10-2011, 12:04 AM
...The miracle of the CD concept (as I've discussed long ago) is not its complexity but its extreme electro-mechanical simplicity...Here are some pictures of just how few parts are needed to make a CD mechanism. The three key elements are the laser arm, the motor and the means of holding the disk and/or ejecting it.

Here (http://www.aacctv.com/cdmewikslapi.html) is the whole shooting match. Move the mouse on this image of the laser arm (http://www.aliexpress.com/store/401439/209815221-372255492/Free-shipping-Optical-pick-up-OPC-A15-for-Auto-CD-DVD-Laser-Lens-Pickups-10pcs-.html) to see how simple it is. The data streams right out of the laser pickup through what is probably these days just one IC. A simpler, more ecologically friendly, lower cost device for spinning a disc you cannot imagine. It is the last word in engineering efficiency, and low, low cost. Many images of the parts needed to assemble a CD/DVD transport here (http://nada.en.alibaba.com/productgrouplist-209815221/optical_pickup_lens.html#products). Seems that the laser head is under USD1 as I commented previously. So, cut down to the very basics (small circuit board not shown) is the Philips mechanism on the attached picture. Although it doesn't have a drawer, if you were to place a CD on the spindle perhaps weighed down by a puck (as they do on fancy audiophile CD players) you will be able to play the disk and hear music. It just doesn't get simpler or more elegant than that.

Ironically, there are more parts and greater precision of assembly required (and more cost) to make a cassette mechanism than a CD transport*. So there is definitely no correlation between engineering complexity and sound quality - perhaps the opposite is true.

>

*One reason: there are many feedback control systems in a CD transport to take care of wide tolerances. The cassette transport does not have such digital feedback and relies heavily on mechanical precision - which cannot be maintained over a long period due to wear and dirt etc..

jplaurel
13-10-2011, 01:58 AM
It's hardly worthwhile to argue about the merits of the CD format any more since it won't be with us for much longer, save for the Redbook encoding standard of 16 bit / 44100 Hz. As Alan and others have pointed out, the Sony/Philips engineering team did a masterful job of designing a practical and extremely fault tolerant medium along with players that could be produced in large numbers at low cost by unskilled labor. But if you look around the developing world, you'll see that people are finding that streaming music is even cheaper and even more reliable. It takes us from the simple CD mechanism to, well, no mechanism at all once we rid ourselves of mechanical hard drives. Years before the practice became popular here in the West, I started to see taxi drivers in places like Myanmar plugging USB keys into slots on the faceplates of their car stereos. I for one am glad to see CD players disappear from the scene.

A few months ago, a friend of mine and I set up a little demo for ourselves. We took a pair of MacBook Pros and connected them via S/PDIF (Mac notebooks have optical interfaces integrated into their headphone jacks) to a Bel Canto C5i integrated amplifier, which has dual optical inputs. We queued up the same track on both MacBooks - one was an Apple Lossless rip from Ray Charles' "Genius Loves Company" CD. The other was purchased as a 24bit/88.2kHz file from HD Tracks. We started both Macbooks at the same time, which allowed us to do some A/B tests comparing the two files. We used a pair of Mackie HR624 studio monitors connected to the Bel Canto's preamp output and listened in the nearfield*, around 8 feet from the speakers.

We each closed our eyes and listened while the other switched inputs on the Bel Canto from one optical input to the other. The only difference we could discern was that the 24/88.2 tracks gave a us a larger mental "picture" of the performance. It was as if, by switching from one track to another, we were switching between two rooms, the 24/88.2 room about 20% larger than the 16/44.1 room.

Could we hear the difference between 16/44.1 and 24/88.2? Yes, we could discern the difference blindfolded 100% percent of the time, but only when switching between sources.

Could we walk into the room blindfolded and identify which version of the track was playing? Absolutely not.

I would like to try this again, eliminating some of the variables. Among them:

1) Were we listening to the same recording at two different resolutions, or was the 24/88.2 version remastered? Surely the "bigger room" effect we heard could be added in the mastering process.

2) Was the 24/88.2 version simply and "uprezzed" version of the Redbook track? There have been some scandals surrounding some companies selling "HD" recordings who have been doing just that, though I don't think HDTracks has been involved. In this case, the "bigger room" effect could be a by product of the algorithms used to pad the data.

3) We did not switch MacBooks. It is possible that variances in manufacturing of the S/PDIF interface or even the particular instance of iTunes on each machine could have introduced the difference. Another possibility is that the MacBook's S/PDIF interface behaves differently at various sample rates.

4) We did not switch DACs. The Bel Canto was the only DAC that had dual S/PDIF ports and upamples to 24/192. The sound difference we heard could be attributed to the DAC upsampling. I now have a Wyred4Sound DAC2 that I will use to continue these tests at some point.

Last year, I watched a demo conducted by John Atkinson using some of his own recordings. Without telling us what he was doing, he played the same recordings at a variety of sample rates, ranging from 24/88.2 all the way down to a 128mbps MP3. He played each version and after each (lower resolution) version, asked us if we heard any difference. And guess what? Not a single person in the room detected a difference in the sound!

Something to think about...

{Moderator's comment: * listening 8 feet from the speakers cannot be described as 'nearfield', it is 'midfield'.}

A.S.
13-10-2011, 10:12 AM
... We each closed our eyes and listened while the other switched inputs on the Bel Canto from one optical input to the other. The only difference we could discern was that the 24/88.2 tracks gave a us a larger mental "picture" of the performance. It was as if, by switching from one track to another, we were switching between two rooms, the 24/88.2 room about 20% larger than the 16/44.1 room....Wonderful experiment. I'm fascinated by how well-intentioned audio enthusiasts structure 'comparative tests'. As you say yourself, there are a number of uncontrolled variables which unfortunately leave the results open to interpretation. The most obvious one is that neither you nor I, as ordinary members of the public, have absolutely no awareness of the mysterious process of 'mastering' these recordings. We would be barred from the CD mastering facility. Their tricks and techniques are closely guarded commercial secrets. Their secret business is of increasing the appeal of recorded music. The more they sell the better so 'mastering' is an absolutely crucial step in the commercial process of bringing music from the recording studio to our homes. 'Whatever it takes' is their motto.

How about these two recordings from last night's live concert of Rachmaninov's 3rd piano concerto. Let me set the scene: "one recording is from the standard low-bit rate feed, the other from the high bit rate feed". Can you hear the difference between them? And how would you describe the sound - especially the 'spaciousness' of the sound of the piano and hall. The volume levels are identical. These are presented here as 196kb 48kHz MP3 = very high quality. Allow time for the players to load (big files).

/library/mp3files/Rachmaninov_SD.mp3 SD example

/library/mp3files/Rachmaninov_HD.mp3 HD example

Kumar Kane
13-10-2011, 02:23 PM
Last year, I watched a demo conducted by John Atkinson using some of his own recordings. Without telling us what he was doing, he played the same recordings at a variety of sample rates, ranging from 24/88.2 all the way down to a 128mbps MP3. He played each version and after each (lower resolution) version, asked us if we heard any difference. And guess what? Not a single person in the room detected a difference in the sound!

Something to think about...

{Moderator's comment: * listening 8 feet from the speakers cannot be described as 'nearfield', it is 'midfield'.}

All my CDs are now on a music server, ripped using Apple lossless. For sure to me, the music sounds just the same as when I play the CDs through a well specced SACD player.

There are three penalties to doing this as compared to AAC at 128 mbps. The larger HDD to carry the files, which isn't such a big factor with costs spiraling down for the memory. Then the price one pays as the battery of the iPod runs down a lot faster when replaying lossless files. For portable listening, that can be a disadvantage. It doesn't matter at home when playing the music from a docked iPod when charging is also happening at the same time as music replay. Third, and most important, for listening via wifi across the home, the uncompressed files demand more of the wifi network than the compressed versions that can sometimes play without interruptions when the uncompressed ones may not.

Given the above, is lossless ripping an overkill with more cons than pros?

A. E.
13-10-2011, 05:20 PM
[QUOTE=A.S.;15964]

(audio clips here, see post #32)

I haven't got my Harbeth speakers yet (two monthes left for November shipping)... when I listen both recordings through my cheapo computer speakers:

first recording has (relatively) less bass and more (irritating) treble; lack of dynamics; no spaciousness at all... latter one has made me feel the heaviness of the piano and I could hear the wall limits of the performance hall surprisingly, I didn't know my computer speakers are capable of producing such details.

jplaurel
13-10-2011, 11:17 PM
All my CDs are now on a music server, ripped using Apple lossless. For sure to me, the music sounds just the same as when I play the CDs through a well specced SACD player.



For a variety of reasons, a music server can actually have superior audio quality. One reason is that a CD transport gets just one chance at sending the bits to the CD player's internal DAC. CRC failures on a damaged CD may result audible interruptions in the sound from a traditional "real time" CD player. Unlike a track ripped by computer, the CD transport cannot go back and re-read a section of data that fails a CRC check and apply an error correction algorithm. With a computer, you may be able to successfully rip a track from a surface-damaged CD that cannot be played properly with a CD player.



There are three penalties to doing this as compared to AAC at 128 mbps. The larger HDD to carry the files, which isn't such a big factor with costs spiraling down for the memory. Then the price one pays as the battery of the iPod runs down a lot faster when replaying lossless files. For portable listening, that can be a disadvantage. It doesn't matter at home when playing the music from a docked iPod when charging is also happening at the same time as music replay. Third, and most important, for listening via wifi across the home, the uncompressed files demand more of the wifi network than the compressed versions that can sometimes play without interruptions when the uncompressed ones may not.

Given the above, is lossless ripping an overkill with more cons than pros?

No, I don't think it's overkill. As you point out, the cost of storage continues to drop. Over 10 years ago, and largely due to storage limitations, I ripped much of my collection at 128mbps. What a waste of time, as I've had to do it all over again. Lesson learned! While Apple Lossless and FLAC are indeed non-lossy formats, they are both compressed and so consume less storage space. The compression does not affect sound quality, since the files are decompressed in real time by the player. Think of lossless compression like a Zip file. When you open that Zip file, there is no loss of "fidelity" in your documents, right?

We moved to streaming music in our house about a year ago. Once we upgraded our network from a rag-tag assemblage of junk and tangled wires to a more rationalized topology, streaming 16/44.1 lossless files wirelessly has not been a problem. We still have the occasional dropout here and there, and it's worse with 24/96 material, but in the face of the many conveniences offered by the system, it's only a minor annoyance. You can eliminate these minor dropouts completely by hardwiring your streaming device to the network. Better quality wireless routers will also make a big difference.

There is now an option in iTunes that will convert your lossless music to 128kbps during the sync process. With this option enabled, you can enjoy lossless audio on your computer, while conserving storage space and battery power on your iDevice.

jplaurel
13-10-2011, 11:57 PM
[QUOTE=A.S.;15964]How about these two recordings from last night's live concert of Rachmaninov's 3rd piano concerto. Let me set the scene: "one recording is from the standard low-bit rate feed, the other from the high bit rate feed". Can you hear the difference between them? And how would you describe the sound - especially the 'spaciousness' of the sound of the piano and hall. The volume levels are identical. These are presented here as 196kb 48kHz MP3 = very high quality. Allow time for the players to load (big files).

(audio clips here, see earlier post #32)

I listened to these on my desktop system with the speakers around 76cm from my ears. @HUG-1, that would be near field, right? ;-) To me, the difference in these two files is dramatic and obvious to anyone. It's the same effect I described in my earlier post. On the "HD" file, the sound is more spacious. The hall sounds bigger.

I just asked my lovely wife to come in and help me with a little test. She clicked randomly on one file or the other 10 times and asked me which was playing, then recorded whether I was correct or incorrect. I scored 9 out of 10 correct. Identifying them by switching A/B was very easy in a single sitting. Interestingly, my incorrect answer was the first, which leads me to ask whether I could have identified the files walking into the room stone cold with a few minutes break between attempts. In that sort of test, I expect my score would not be so good. I'll see if I can get her to help me do that test over the next day or so.

I still believe that it would be possible to achieve the "larger room" sound of the HD file during the mastering process with a lower bitrate. For all we know, Alan's two recordings may be identical except for some DSP effects.

Diminish
14-10-2011, 12:05 AM
"CD transports are elegantly simple devices. Have you looked inside one? You just can't get simpler than a motor, a spindle and a laser arm and a little processing logic. Would you like us to disassemble one to show you?"

Thanks, but I've already seen a transport. If your purpose in showing me would be to persuade me; that a mechanism that uses 3 servos (rotational, focus, and tracking), a laser, pickup, and photo detector to read objects that are about 1/100th the size of a human hair; process, extract, and perform error correction on this data, and generate another completely separate bitstream, while maintaining picosecond time domain accuracy throughout; that this is a simple process, I'm afraid that you'd be wasting your time. I've already defined the word "complex" and admitted that far greater complexity exists. The gauge for comparison was the player's DAC; not the Mars Mission or a cassette head. Its not the parts count that accounts for complexity. I'm speaking about the volume of information that is input and output along with the transport's inherent precision, and the fact that this occurs on mechanical, optical, and electronic levels.

There's little agreement in the audio world as to whether simplicity invariably equates to improved sonics. If I'm not mistaken, Harbeth favors comparably complex crossover designs. Most high end component manufacturers employ highly complicated power supplies with very simple analog circuits.

Once again, I was not attributing differences in sound quality among CD players specifically to the degree of complexity within the transport. My point was that factors occurring in the generation of a SPDIF bitstream can audibly influence sound quality. Sub-optimal performance in any of the (electronic, mechanical, or optical) functions has the potential to degrade the output. This potential simply doesn't exist in the DAC (functioning only in the electronic domain). I chose to use the word "complex" to speak to the fact that a transport combines these operations. While not incorrect, in any sense, perhaps a better choice of words would be; multifarious, heterogeneous, divergent, or manifold. We are in agreement that the CD transport is a marvel of engineering, so how about if we just leave it at that?

HUG-1
14-10-2011, 09:05 AM
Playing an audio disc rotating at "1 time" 1X as audio CDs do is a pathetically slow data rate of 150,000/bits sec (http://en.wikipedia.org/wiki/CD-ROM#Transfer_rates).

The 52X CD reader/burner in this PC has a data rate of 500,000/bits sec. Home ADSL broadband is about the same data rate down-stream.

A typical home CAT5 network will be 100,000,000 bit/s second or thereabouts and Gigabit networks 10x faster again.

In that context reliably reading an audio CD with a conventional laser head and motor transport is a very low technology trivial matter indeed.

Diminish
14-10-2011, 09:20 PM
"Playing an audio disc rotating at "1 time" 1X as audio CDs do is a pathetically slow data rate of 150,000/bits sec"

I think you might have your books confused. The bitrate for Redbook CD is: (44,100 samples/sec.) x (16 bit samples) x (2 channels) = 1,411,200 bits/sec. You are citing a Wikipedia article that is talking about the Yellow Book standard for CD-ROM; indeed apples and, er, lemons. Reading directly from Ken Pohlmann's "Principles of Digital Audio", "CD-Audio is a specific application of compact disc technology; it is a standard for recording PCM audio. The CD-ROM standard is derived from the CD-Audio standard, but defines a format for general data storage." (Pohlmann, 2008, pp.276) CD-ROM/XA (eXtended Architecture) is the most efficient Yellow Book format. It has a bitrate of 1.4Mbps, the same as Redbook.
It is important to recognize that the 1.4Mbps data rate for CD refers to the SPDIF output of a transport. The EFM coding that actually appears on the disc itself is read at 4.3218Mbps. We have to allow for the subcode, modulation, TOC data, and clock synchronization information. So, if you want to get caught up in numbers, this is well over 4 times the data rate of your CAT5 network!

STHLS5
15-10-2011, 12:06 PM
"Playing an audio disc rotating at "1 time" 1X as audio CDs do is a pathetically slow data rate of 150,000/bits sec"

I think you might have your books confused. The bitrate for Redbook CD is: (44,100 samples/sec.) x (16 bit samples) x (2 channels) = 1,411,200 bits/sec. You are citing a Wikipedia article that is talking about the Yellow Book standard for CD-ROM; indeed apples and, er, lemons. Reading directly from Ken Pohlmann's "Principles of Digital Audio", "CD-Audio is a specific application of compact disc technology; it is a standard for recording PCM audio. The CD-ROM standard is derived from the CD-Audio standard, but defines a format for general data storage." (Pohlmann, 2008, pp.276) CD-ROM/XA (eXtended Architecture) is the most efficient Yellow Book format. It has a bitrate of 1.4Mbps, the same as Redbook.
It is important to recognize that the 1.4Mbps data rate for CD refers to the SPDIF output of a transport. The EFM coding that actually appears on the disc itself is read at 4.3218Mbps. We have to allow for the subcode, modulation, TOC data, and clock synchronization information. So, if you want to get caught up in numbers, this is well over 4 times the data rate of your CAT5 network!

CD transfer rate is 1200kb/s or 150kB/s or 0.14MB/s.
10base Ethernet in the 80s was at 1.25MB/s.
Fast Ethernet in 1995 was at 12.5MB/s.

Diminish, I have the earlier edition of Pohlmann but unable to find the info about 4.3218Mbps for EFM coding.

ST

Diminish
16-10-2011, 01:12 AM
@ STHLS5: "Diminish, I have the earlier edition of Pohlmann but unable to find the info about 4.3218Mbps for EFM coding."

C'mon, I'm not making this stuff up! One place it can be found is in the chapter entitled "The Compact Disc", p.244 in the 4th Edition. "Each audio disc stores a stereo audio signal comprised of two 16 bit words sampled at 44.1 kHz; thus 1.4 million bits / second of audio data are output from the player. Other data overhead such as error correction, synchronization, and modulation are required. Altogether the channel bit rate, the rate at which data is read from the disc, is 4.3218Mbps."

The figures given by HUG-1 simply were not correct. The 150,000 Bps figure for CD ROM is in Bytes (not bits) per second. Internet connections as well as CD players are concerned with bits per second. More notably, the Yellow Book standards for CD ROM are not particularly relevant to a discussion on Redbook vs. hi-res audio.

STHLS5
16-10-2011, 01:58 PM
@ STHLS5: "Diminish, I have the earlier edition of Pohlmann but unable to find the info about 4.3218Mbps for EFM coding."

C'mon, I'm not making this stuff up!..
...

Thanks. I found it. It was never my intention to suggest you are making up those figures. :)

You mentioned earlier “ the disc itself is read at 4.3218Mbps............this is well over 4 times the data rate of CAT5 network”. I am only interested to that statement and not about the general discussion about CD vs Hi-Rez.

In the wikipedia (Redbook standards) it is stated that the raw bitrate at optical pick up is 4.3218Mbps but it is not exposed to the application reading the disc. The actual data read is 2048 bytes per sector x 75 sectors per second = 150KiBytes/s (1228.8 kbit/s).

Even if we agree that the transport reads 4.3128Mbps, it is still about 0.54MB/s which is far below than the earlier 10base Ethernet capabilities. So how can it be over 4 times the data rate of CAT5 network?

(Note: 8 bits (b)= 1 byte(B))

ST

Diminish
16-10-2011, 10:36 PM
@ ST "In the wikipedia (Redbook standards) it is stated that the raw bitrate at optical pick up is 4.3218Mbps but it is not exposed to the application reading the disc. The actual data read is 2048 bytes per sector x 75 sectors per second = 150KiBytes/s (1228.8 kbit/s)."

I'm not sure what you mean by the distinction "not exposed to the application reading the disc". The optical pickup is what reads the disc, correct? If you intend the DAC section as the "application reading" the data and define the data to be read as the SPDIF audio stream, I agree completely. I've said several times now that the transport is concerned with much larger amounts of data than the DAC section. This, along with the fact that this process exists in mechanical, optical, and electronic domains, represents the entire basis for my argument. Your Wikipedia article says "By comparison the bit rate of a "1x" data CD is defined as ... (1228.8 kbits/s)" The 150KBytes/sec. figure was also for the data CD. So, the difference is that the data CD has a slightly slower data rate (1411.2kbit/s versus 1228.8kbit/s), so what?

Now, in terms of the comparision to networking. I misread HUG-1's 1,000,000,000 bits/s figure, and regarded it at 1,000,000 bit/s. Since large bit / byte rates are normally given with Kilo or Mega prefixes, I misinterpreted his unit by a factor of 10 which lead to an improper conclusion. I was completely wrong in the statement that a CD transport's data rate exceeds that of such a network, however, I don't see where this nullifies my baseline contention.

One major difference between a modem and a CD player is the importance of timing. For accurate playback, not only must the DAC decode the correct value, but it must do this at precisely the right time. Any deviation from this is known as "clock jitter". This is a difficult thing to measure because the time intervals are so minuscule. There are also different types of jitter (random and deterministic are two types) with deterministic jitter being the more sonically detrimental. Disparities in the pico second rage (1/1000000000000 of a second) can be audible.

Internet protocol involves data being sent in discrete packets where timing is much less crucial. Another reason why this is not a fair comparison is the method of data transfer. CAT5 cables carry parallel data where bytes of data can be transferred through many different paths. Generally speaking, the more channels available for transmitting data, the faster the transfer and greater the throughput. The SPDIF specification is for serial transfer over a 75 Ohm coax.

I am not and was not contending that a CD transport represents the largest, or fastest method of data transfer. Neither am I saying that it is state of the art in 2011. One has only to look at a Blueray mechanism to see far greater data capabilities. For the last time, the point was that; due to the potential for errors in the mechanical, electrical, and optical domains and the higher data rate present in the pickup, that a transport would have more potential to effect the overall sound quality than the player's DAC. I don't know that there's much to be gained in exploring it any further.

Personally, I would much rather resume the conversation about Redbook vs. Hi-Res. Along those lines, I purchased some tracks from AIX Records (iTrax) yesterday and was very impressed with the quality of sound of the Jazz and Folk tracks. I also got 6 tracks from their Classical catalog, but I was somewhat less than impressed by these.
All of the tracks were 24 bit 96kHz Hi-Res. LPCM. I bought them as WMA Lossless files, but its also possible to buy the entire CD Audio files. You can get them in 2 channel or 5.1 surround from a Stage or Audience perspective. I only concern myself with 2 channel. I converted the WMA's to FLAC to be consistent with the rest of my Library. Prior to deleting the WMA's, I listened for differences in the FLAC files and heard absolute nothing. I also burned a CD copy which effectively "downsamples" them to Redbook. In order to do a comparison, I have to listen to the Hi-Res. from my computer, and compare that to the 16/44 from my transport through the same DAC. I could downsample in JRMC or rip the CD's back into the Library for a closer comparison, but I think that the above method is sufficient.

You could argue that the JRMC software is imposing a sonic characteristic during encoding, decoding, importing, burning. Using my CD player as a transport would certainly allow for some differences. I use a Sonicweld Diverter 24/96 USB>SDIF converter for computer playback. This is a high quality device that may well yeild a better (less jittery) SPDIF output than my Marantz R15S2. That notwithstanding, the sound is quite good on the Jazz and Folk tracks through CD or JRMC. I hear the same drawbacks to the Classical tracks through either medium, but the Clarinet's texture becomes a bit harder on CD. The soundstage is a bit better defined on the Hi-Res. material and perhaps a bit deeper. Comparing from memory, in a broad sense, I would say that the sound offered by the best of the AIX tracks exceeds the best I've heard from CD.

{Moderator's comment: noted about the hires tracks and Alan's demonstration recently of 'spaciousness'. What did you make of that demo?}

EricW
16-10-2011, 10:55 PM
In the wikipedia (Redbook standards) it is stated that the raw bitrate at optical pick up is 4.3218Mbps but it is not exposed to the application reading the disc. The actual data read is 2048 bytes per sector x 75 sectors per second = 150KiBytes/s (1228.8 kbit/s).

ST

Actually, according to the Wikipedia article you cite, the 2048 bytes per sector figure is for a data CD (CR-ROM). The figure for an audio CD - which I think is what this discussion is about - is 2352 bytes per sector. The 75 sectors per second figure is the same.

STHLS5
17-10-2011, 01:25 AM
Hi Diminish, thanks for clearing up the confusion. Please carry on with the discussion about Hi-Rez but I have reached a point that my ears only good enough for CDs only. Though, I prefer to buy SACD, XRCD, HQ etc etc I believe their superiority is in recording or mastering techniques and not in the format. I am even contended with MP3 nowadays after realizing some oldies that I was listening were actually in MP3 and I didn't even realize that.

I just learned how to use my laptop as a music server using the ONkyo NDS-1 as an interface to my legacy DAC Theta Digital GenIII and my young children didn't even notice any difference until I began side by side comparison. And speaking of hi-Rez, it is only recently I found out my SACD Marantz Reference SA11S2 is using the the good old 44.1kHz 16 bit to play Cd. Even though, the industry standard for most high end player is 24bit and 196khz DAC, Marantz engineers thought it was okay to stick to the old 16bit/44.1Khz and it was positively reviewed by Stereophile.


Actually, according to the Wikipedia article you cite, the 2048 bytes per sector figure is for a data CD (CR-ROM). The figure for an audio CD - which I think is what this discussion is about - is 2352 bytes per sector. The 75 sectors per second figure is the same.

Yes, you are correct but the 256 bytes of CRC and another extra 48 bytes do not contain any data. So technically only 2048 is important for the discussion above in regards to data transferred.

I am no expert in digital audio so any further arguments by us about what is the actual data stored, read or transferred would be like the story of the blind men and the elephant.

ST.

Kumar Kane
17-10-2011, 06:48 AM
When one talks of high resolution, the impact is very marked in video, with the difference between hidef and standard very clearly visible to anyone that sees it, trained eyes or not, be it Bluray DVD or HDTV via satellite. And video seems to be making further leaps, with 3D. Although even the current solutions are clunky ( glasses required ), I guess progress will continue, to being able to see realistic 3D as easily as one sees 2D today.

That certainly does not seem to be the case with audio for music listening with no video involved, which seems to be at the end of the road. What, I wonder would be an equivalent leap? There has been much progress from a convenience standpoint with digital audio, music servers, internet music services, multi room playback and the like, but my question is towards the quality side of things, where there doesn't seem to have been any real progress for many years now.

Diminish
17-10-2011, 06:40 PM
"{Moderator's comment: noted about the hires tracks and Alan's demonstration recently of 'spaciousness'. What did you make of that demo?}"

Hi, since you asked, I went ahead and listened to the Rach. tracks. There were some notable differences that I picked up on: the SD track sounded more distant, or another way of saying this, would be that it was more "laid back". At times, it sounded flat, but when the full range of the piano was invoked, I had to question that. The wind instrument (flute?) that comes in during the final seconds seemed further from the piano than in the HD.

In the HD track, I thought the piano sounded closer; a more "forward" perspective. The most significant difference was longer reverb. trails ("note decay") in the HD recording. The wind instrument appeared closer to the piano. If you take that along with the observation that the flute sounded farther away in the SD, and the forward perspective noted on the HD compared to the laid back SD track; it would certainly seem that I'm saying that the SD version conveyed more spaciousness.

Well, that's not exactly what I mean to say. I heard more "air" in the HD recording although it was closer in perspective. I also heard more depth, or 3 dimensionality, in the HD although the SD seemed placed further back. Whatever the case, I was able to readily distinguish between the two during blind trials.

Am I correct that what we are listening to two 192kbs tracks; one taken from a 24/88 Hi Res. and the other a standard Redbook? Honestly, I would have expected the lossy conversion to mask most of the details that were preserved in the 192kbs tracks.

When I do these comparisions at home, I'm able to directly compare Hi Res. material with Redbook by routing both through the same software, USB>SPDIF converter, coax cable, and DAC. Most of the time, I hear less disparity than what was revealed by the 2 examples here. With one notable exception, I have yet to hear a true "Night and Day" difference.

I recently purchased YES's "Fragile" from HD Tracks. If I compare one of the songs on that album with the same song from another album, Classic YES has some of the same songs. There is a huge difference. I never thought that Classic YES was very well recorded to begin with, but they are a hard band to capture. Comparing Long Distance Runaround, there simply is no comparison. Its impossible to focus on one specific area where the 24/96 is better; it should be obvious to anyone; even audiophobes and music haters. I'm not sure that these are the same recording, and therefore that the only difference is the resolution. Long Distance Runaround is the same duration on both albums, but the recording volume is lower on Classic YES. This could be due to the 8 extra bits.

Generally speaking, what I normally hear in terms of differences is most notable on classical recordings. Most CD's portray massed strings as a single big instrument rather than a group of individual instruments playing together. For some analog buffs, any digital reproduction of stringed instruments is anathema. While still not to the level of good analog, Hi Res does a better job than Redbook for sure. SACD is even better than the PCM formats at this particular task. In general treble has less offensive glare or hardness, bass is better defined in terms of pitch, and the midrange somewhat more compelling.

There are many experts who feel that DSD (the SACD coding) masters produce better Redbook sound. I also think that record labels who produce Hi Res. digital care more about sound reproduction. Much less, if any, dynamic compression takes place.

Significant thought is given to microphone placement and less mixing, and for the most part no overdubbing takes place. A big advantage of higher bit word lengths is a greater dynamic range and more precision within this range. Higher sampling rates capture more sonic information and allow for more low pass gradual filters.

Pluto
17-10-2011, 07:16 PM
That certainly does not seem to be the case with audio for music listening with no video involved, which seems to be at the end of the road. What, I wonder would be an equivalent leap?
Ambisonics starts to bridge the gap between recorded sound being a mere photograph, and reality.

Loudspeaker manufacturers would love it too :-)

Sadly, the required positioning of the loudspeakers is prohibitive for all but the most devoted.

kittykat
20-10-2011, 06:17 AM
It's hardly worthwhile to argue about the merits of the CD format any more since it won't be with us for much longer...

That’s quite a big call.

Looking at Billboard’s market watch stats (24th Sept edition), 212 million albums were sold in the last 12 months, of which 140 million (66%) were in CD and 32% (68 million) in digital. Digital album sales climbed 20% y-o-y. At this rate, digital album sales would be greater than CD album sales sometime between 2014 and 2017. At the current trajectory of 4% CD album sales decline y-o-y, CD sales could still top a hundred million per year in 2020 (and that’s almost 40 years after its introduction).

Imo, what makes most people think the “CD is dead” is due to digital track sales. 889 million tracks (or 301 million equivalent albums) were sold last year. If we add digital tracks to digital album sales, digital sells 2.5 times more than the physical. The demand for albums (and CD) should however not just drop off, especially if 47% of album sales are for catalog and approximately 53% for current music. What the figures don’t report is the proportion of catalog and deep catolog by format. I suspect most catalog sales is in CD format.

As long as there are still people who enjoy music and are pupils to it, enjoy artwork, the smell of print and the tactility of touching an album, CD’s (or any physicals) could still be around for a while.

Your Myanmar taxi driver could be in this group and if he is, I’m very sure he kept his CD copy safely at home.

HUG-1
20-10-2011, 12:56 PM
"{Moderator's comment: noted about the hires tracks and Alan's demonstration recently of 'spaciousness'. What did you make of that demo?}"

Hi, since you asked, I went ahead and listened to the Rach. tracks. There were some notable differences that I picked up on: the SD track sounded more distant, or another way of saying this, would be that it was more "laid back". At times, it sounded flat...Last chance to comment on these test tracks (http://www.harbeth.co.uk/usergroup/showthread.php?1293-The-truth-about-high-resolution-audio-compared-with-std.-CD-44k&p=15964#post15964) before we look at them technically ..................

Just as with all matters concerning audio there are no "right" answers and no "wrong" answers. Everything is in the grey area between and a matter of personal perception.

Pluto
20-10-2011, 09:27 PM
Last chance to comment
Listening only on naff computer speakers -

HD has more stereo width, possibly mainly at the lower signal levels. Technically speaking, only the louder elements of the 'S' component ('S' = width for these purposes) are making it through the codec. As the hall acoustic exists mainly within the 'S' component, the narrower (SD) example exhibits less of the hall acoustic.

A.S.
21-10-2011, 10:53 AM
Listening only on naff computer speakers -

HD has more stereo width, possibly mainly at the lower signal levels. Technically speaking, only the louder elements of the 'S' component ('S' = width for these purposes) are making it through the codec. As the hall acoustic exists mainly within the 'S' component, the narrower (SD) example exhibits less of the hall acoustic.... the professional (sound engineer) listener comments!

One point I should have made long ago is that I only generate and test these audio clips on my own $30 plastic pc speakers. I do not play them through quality speakers or hi-fi system because I am not intent on revealing some extremely subtle nuance but a general point. And I do that by allowing a side-by-side comparison to be made by the listener And for that, your plastic PC speakers should be perfectly adequate. For about $30, Logitec (a brand that makes a wide range of well engineered pc accessories) offer several speakers: these here used to make the clips are their LS11.*

Turning to these two clips first presented in post #32 ...

/library/mp3files/Rachmaninov_SD.mp3 SD example

/library/mp3files/Rachmaninov_HD.mp3 HD example

The listener's feedback was as I expected and is neatly summarised by Pluto above. 'The HD recording has more stereo width'. Assuming that we agree on that (listen again to the repeated clips above) we can pursue why this is. Without any further background information, you and I casually listening could draw the conclusion that the HD recording brought some additional realism, a greater 'being there' experience. And probably we would cheerfully cough-up an extra few (or many?) dollars for that masterpiece recording even if we already owned the 'SD' recording. That is how the movie and recording industry works; they are very creative in selling you (again) what you already have. Be it VHS>DVD or DVD>BluRay, or LP>CD then CD>Remastered CD. It's a game.

In my post #32 introducing these clips and running with the flow of the discussion I said -


... neither you nor I, as ordinary members of the public, have (any) awareness of the mysterious process of 'mastering' these recordings. We would be barred from the CD mastering facility. Their tricks and techniques are closely guarded commercial secrets. Their secret business is of increasing the appeal of recorded music. The more they sell the better so 'mastering' is an absolutely crucial step in the commercial process of bringing music from the recording studio to our homes. 'Whatever it takes' is their motto.

Now the sad fact is that every commercial recording once 'in the can' is frozen in time at the day it was captured, with those performers, those microphones and with the limitations of recording skill and technical equipment on the day. Sounds not 'on' the recording are not on the recording - period. The recording is as complete and sealed as an oil painting. Mono cannot be regenerated as surround sound in post-production. But for marketing purposes, ways have to be found to 'leverage' the significant cost invested in the recording to find new consumers for it. And since music is a highly personal subjective matter, the most likely new market for a re-release is those that have 'already expressed a preference for' (marketing speak) the artist. And so, the crucial importance of remastering what was sealed at a point in time into something new, fresh and sellable.

The truth is that both of my recordings clips started out as exactly the same. I simply took the original high quality recording and duplicated it. The original I labelled 'SD' and the copy I manipulated - I remastered - and labelled it 'HD'. With a little appreciation of listener preference behaviour (i.e. the sort of things that most people would find audibly attractive most of the time) it took just a few minutes to remaster the clip. I'm sure you have the tools to make the same transformation on your PC: you can remaster your entire audio collection for free! More spaciousness, more open, greater dynamics - more revealing, a greater sense of scale etc. etc. etc. .... all there at the click of a few keys.

What did I do? Can you do it yourself? What can we learn from this?



*The sound quality of active plastic pc speakers can be fairly good. The usual problem though is hum, both mechanical and electrical.

Kumar Kane
21-10-2011, 01:18 PM
The truth is that both of my recordings clips started out as exactly the same. I simply took the original high quality recording and duplicated it. The original I labelled 'SD' and the copy I manipulated - I remastered - and labelled it 'HD'. With a little appreciation of listener preference behaviour (i.e. the sort of things that most people would find audibly attractive most of the time) it took just a few minutes to remaster the clip. I'm sure you have the tools to make the same transformation on your PC: you can remaster your entire audio collection for free!

Why am I not surprised?!:-)) I was expecting something on these lines, and I now look forward to reactions....all of this is like photoshop for audio.

Pluto
21-10-2011, 02:48 PM
What can we learn from this?
We can learn to be more forthright! I has assumed that we were comparing the Radio 3 "hi-def" AAC feed with the lower quality WMA feed.

When I played these (quite late at night), I had a feeling that the "wider" one felt a bit too wide - width added by increasing the proportion of the 'S' component, i.e. artificial!

Had I spoken my mind (instead of thinking "time for bed") I would have had our evil moderator bang to rights :-)

That said, on the whole topic of remastering, I have a few "remastered" CDs that are vastly better than the original releases, the quality of the converters having come on in leaps and bounds between then and now.

I have also heard several remasters that suffer badly, in the latter releases, from excess limiting. "Loudness war" stuff.

A. E.
21-10-2011, 07:15 PM
*The sound quality of active plastic pc speakers can be fairly good. The usual problem though is hum, both mechanical and electrical.

I do understand now, why some ladies are happy with kitchen radio

A. E.
21-10-2011, 07:26 PM
What did I do? Can you do it yourself? What can we learn from this?


Dear Alan,

This shows me I can enjoy all my digital archive after a little touch, regardless of the other components like speaker stands, cables, pre and power amplifiers...

I could photoshop my raw photographs in the very first day, but it took me about a year to learn to get what I want exactly.

I don't understand how you did what you did, at the moment; but I want to know how to do it by myself...

Kumar Kane
22-10-2011, 03:12 PM
What did I do? Can you do it yourself? What can we learn from this?

Hi fi = high fidelity. Doesn't all of this now beg the question, fidelity to what? How is one to know just what is the reference any more?

A. E.
22-10-2011, 10:27 PM
Hi fi = high fidelity. Doesn't all of this now beg the question, fidelity to what? How is one to know just what is the reference any more?

who will choose the "reference" while everybody hears and perceives differently... I'm not sure even my L and R ears hear the very same... There should be more than one reference fidelity, tailor made for everyone...

On the other hand, time changes everything... When I was new at Photoshoping, all of my images were sharpened extremely and the colors were oversaturated, but just the opposite now. So even my own reference changes for getting further by time...

jplaurel
23-10-2011, 12:36 AM
No surprise here. As I said in my earlier response:

"I still believe that it would be possible to achieve the "larger room" sound of the HD file during the mastering process with a lower bitrate. For all we know, Alan's two recordings may be identical except for some DSP effects."

What have we learned? That much of the music from HDTracks sounds better than the original CD versions because of the remastering rather than the increased bit depth or higher sampling rates. Maybe it's possible for some very young people to hear differences in bit depth and sampling rates beyond Redbook, but at 50 years old, I can't.

Quick aside about the acute hearing of young people: Years ago, when my son was still in high (secondary) school, we were talking about kids having mobile phones in class as his school had recently implemented a policy requiring that they be turned off. He laughed off the policy, stating that phones are ringing in class "all the time" and the teachers have no clue. The kids' solution to the mobile policy was novel. He hit a few keys on his phone and said "can you hear that"? I couldn't. It turns out that the kids didn't turn their ringers off at all. They merely switched to high frequency ringtones above the threshold of the teachers' hearing. A very simple and clever solution.



The truth is that both of my recordings clips started out as exactly the same. I simply took the original high quality recording and duplicated it. The original I labelled 'SD' and the copy I manipulated - I remastered - and labelled it 'HD'. With a little appreciation of listener preference behaviour (i.e. the sort of things that most people would find audibly attractive most of the time) it took just a few minutes to remaster the clip. I'm sure you have the tools to make the same transformation on your PC: you can remaster your entire audio collection for free! More spaciousness, more open, greater dynamics - more revealing, a greater sense of scale etc. etc. etc. .... all there at the click of a few keys.

What did I do? Can you do it yourself? What can we learn from this?

*The sound quality of active plastic pc speakers can be fairly good. The usual problem though is hum, both mechanical and electrical.

jplaurel
23-10-2011, 12:44 AM
*The sound quality of active plastic pc speakers can be fairly good. The usual problem though is hum, both mechanical and electrical.

@Alan: I hear what you're saying about plastic desktop speakers. I once had a pair of the Harmon Kardon Soundsticks with their integrated DAC and miniature 4-driver line array and they sounded astonishingly good. And back when my work environment dictated that I not play music too loudly in consideration of my neighbor in the next office, I had a pair of Bose Computer MusicMonitors. These were active speakers with these teeny-tiny drivers and some sort of passive radiator on the back. They were actually pretty good. Imaging in particular was surprising.

{Moderator's comment: did they like most PC speakers emit a constant hummmmmmmm?}

Pluto
23-10-2011, 11:12 AM
It turns out that the kids didn't turn their ringers off at all. They merely switched to high frequency ringtones above the threshold of the teachers' hearing. A very simple and clever solution.
I think the teacher needs to acquire one of these (http://www.thesignaljammer.com/products/Cell-Phone-Blocker-Mini.html) ;-)

Drdennis
23-10-2011, 02:50 PM
I inherited eleven year old Soundsticks from my daughters college system. After sitting in storage for several years, I connected them to my new Mac Mini ('10). They are amazing for very near field listening. There is no hum whatsoever. I have considered upgrading to separate amp and DAC with P3's. The cost would be about $4,000, so for now I will listen to this surprising system. Perhaps, Harbeth could improve on a compact desktop system. I'm sure that this is potentially a huge market.

My main system;

Compact 7ES3
REL B3
LFD MK IV
SONY CDP 5400ES, VSE mods
Shunyata PC, Cardas cables

HUG-1
23-10-2011, 04:19 PM
I inherited eleven year old Soundsticks from my daughters college system...Are they active i.e. mains powered?

The hum in these (active) pc speakers comes from the internal mains power supply and/or the transformer causing the plastic case to vibrate.

Drdennis
24-10-2011, 12:21 PM
Soundsticks have an outboard power supply connected to mains.

jplaurel
24-10-2011, 10:36 PM
{Moderator's comment: did they like most PC speakers emit a constant hummmmmmmm?}

No, they did not. The newer "Soundsticks II" version, however, are a step backward. They no longer have the integrated DAC. Instead, you plug a 2.5mm stereo mini jack into your sound card. And they do hummmmmm.

steveinaz
13-02-2012, 03:20 PM
I have a few 24/96 (flac) albums I've down loaded from the Linn site. Realistically, I think it has more to do with the better mastering of these albums, than bit depth. I have many Redbook CD's that sound phenominal--so I know the potential is there. I haven't tried it, but my gut feeling is that if you downloaded the same album in both 16/44 and 24/96 (assuming good mastering), you'd be hard pressed to tell a difference.