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HUG - here for all audio enthusiasts

Since its inception ten years ago, the Harbeth User Group's ambition has been to create a lasting knowledge archive. Knowledge is based on facts and observations. Knowledge is timeless. Knowledge is human independent and replicatable. However, we live in new world where thanks to social media, 'facts' have become flexible and personal. HUG operates in that real world.

HUG has two approaches to contributor's Posts. If you have, like us, a scientific mind and are curious about how the ear works, how it can lead us to make the right - and wrong - decisions, and about the technical ins and outs of audio equipment, how it's designed and what choices the designer makes, then the factual area of HUG is for you. The objective methods of comparing audio equipment under controlled conditions has been thoroughly examined here on HUG and elsewhere and can be easily understood and tried with negligible technical knowledge.

Alternatively, if you just like chatting about audio and subjectivity rules for you, then the Subjective Soundings sub-forum is you. If upon examination we think that Posts are better suited to one sub-forum than than the other, they will be redirected during Moderation, which is applied throughout the site.

Questions and Posts about, for example, 'does amplifier A sounds better than amplifier B' or 'which speaker stands or cables are best' are suitable for the Subjective Soundings area.

The Moderators' decision is final in all matters regarding what appears here. That said, very few Posts are rejected. HUG Moderation individually spell and layout checks Posts for clarity but due to the workload, Posts in the Subjective Soundings area, from Oct. 2016 will not be. We regret that but we are unable to accept Posts that present what we consider to be free advertising for products that Harbeth does not make.

That's it! Enjoy!

{Updated Nov. 2016A}
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Frequencies, sound waves and hearing

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  • #31
    Track 1,2 and 3 appears to be identical. After many repeated tests, I am not able to distinguish if there is really any difference in track 1, 2 and 3 even in the loudness level. Unless, I am stressing to hear differences that may not exist in the first place, I would group 1, 2 and 3 as identical under normal listening conditions.

    Track 4 is without the distortion (i.e, rumble or tape hiss like sound) but occasionally it seems to hit the notes a bit louder than the previous tracks. It appears to be slightly louder, but I think it may be due to notes sounded fuller and maybe due to extended highs and lows. The notes' decay tends to be longer in track 4 which is probably due to the lack of the masking effect of the "vinyl" noise.

    At about the last 2 seconds in track you can hear the words "one for" followed by a soft guitar plucking. In track 1, 2 and 3 the word "for" is almost incomplete and the track ends without the extra note.

    ST

    Comment


    • #32
      Working against prejudices

      Ok, I've done my homework, I listened to the tracks 1 to 4. I must say that this "synthetic vinyl" sound does not represent the real vinyl sound. It reminds me some groups that use this "surface noises" to give their song a style. As an example, I'm thinking here about some pieces from DJ's Kid Koala, a true genious if you don't know him. It's important for me to work against some vinyl prejudices and stereotype.

      On the second hand, I want to be clear with Alan's statement: "I think that we can all agree that listening to analogue is a different experience to listening to digital." I don't. The only "scientific" comparison I had about this was explain above and we, friends and I, can't make any differences between the two formats.

      So, everyone talk about sample #4, but more subtile are the differences between #1-2-3? What are they?

      {Moderators comment: there are no differences between 1,2 & 3. They are the same file presented three times. Sample 4 is unique.}


      Sebastien

      Comment


      • #33
        As Alan said to me just now, we`re back on track now. Good feedback which we all benefit from. Anyone else hear these issues?

        Comment


        • #34
          More on the guitar buzz

          Originally posted by EricW View Post
          ... one thing I do hear in track #4 in particular is some noticeable fret buzz on the guitar on certain notes, as well as some missed/muted notes.
          Good Eric, that is exactly what I hoped you'd hear. Let's listen to it again ... here is the exact same Track 4 as before, but posted below for your convenience...

          4 clean reference recording)

          As you say, if you listen really carefully as the guitar is played, you can hear an accompanying buzzing sound. The 'buzz' has a wideband bright tone to it. It sounds like some part of the guitar structure or strings is resonating but in a non-musical way that has no apparent relationship to the note being played. It truly is a non-musical accompaniment. Perhaps a button on the player's jacket in contact with part of the guitar? Or a glue joint that 's failing on the guitar leaving two parts flapping against each other? It should be audible even on $3 headphones like mine here. I'm not an audiophile and I can hear it.

          OK, the next step is to note very carefully what EricW said. He said ....

          I tried listening for that [buzz] on the other tracks, but it either harder to hear or not there at all...
          Do we agree that when we listen to tracks 1, 2 or 3 that, as EricW says, we can't hear that guitar buzz (clearly or at all) that we can hear on track 4? For convenience, here is track 1, but 1,2 and 3 are identical.


          1 analogue-like recording)
          Alan A. Shaw
          Designer, owner
          Harbeth Audio UK

          Comment


          • #35
            Fret buzz?

            Originally posted by A.S. View Post
            ..Do we agree that when we listen to tracks 1, 2 or 3 that, as EricW says, we can't hear that guitar buzz...

            Sorry, but isn't the fret buzz audible in other tracks as well? Anyone can give exactly where the extra buzzes in track 4?

            Comment


            • #36
              More on the buzz

              Originally posted by STHLS5 View Post
              Isn't the fret buzz audible in other tracks as well?
              The buzz is right on the edge of the noise floor. If you listen you'll possibly hear on 1-3 that the buzz has a much warmer, less bright or less 'toppy' or clean character than on the reference track (4) and significantly, that the buzz periodically disappears under the noise i.e. is swamped by the noise. You'd be justified in saying that the buzz is modulated by the noise as the noise swooshes up and down. Agree?

              Once ones attention is drawn to a sonic issue it's easier to identify it. It's much, much more difficult to hear a sonic issue without a crib, alone, and relying on your own ears. Which is why in my opinion audio design-by-committee is foolish as is listening-by-committee.
              Alan A. Shaw
              Designer, owner
              Harbeth Audio UK

              Comment


              • #37
                This is getting bit complicated for a non technical guy like myself. When the tracks were posted for the first time, I thought track 2 was easier to my ears than track 4 despite the inherent noise in 2. After, several times I guessed 1,2 and 3 probably identical. Now, I am made to understand that the fret buzz ( which is rather a common occurrence due to many factors) wasn't the intended relationship to the note. I have accepted them part and parcel of imperfect guitar in other CDs that I have heard them.

                So could this be the reason why vinyl is preferred because it drowns unnatural and unwanted resonance?

                ST

                Comment


                • #38
                  You cannot assume that what you call fret buzz is actually anything to do with the guitar. Later we can look at what actually is the source of that noise. Now all that matters is that you can hear it. Now we can move on. It is helpful not to try and anticipate the direction Alan is intending to take this subject.

                  V

                  Comment


                  • #39
                    Wax recordings, 78s and noise ...

                    I've spent a couple of hours this afternoon rooting around in local charity (second-hand) shops looking for suitable audio material for the next step. It occurs to me that I should stress yet again, that our sole intention is to illuminate the path to the (technically) highest possible fidelity. That does not of course preclude you from making a decision on what sound you prefer for any component of your replay system. And whatever decision you do arrive at is entirely reasonable given your own value system. If you love CD that's great. If vinyl is your thing - terrific. My own personal weakness is audio cassette, a format I really like for convenience, wide selection of inexpensive audio books and I can play in the car. It is also a format that in the 80s and 90s I invested many long hours in tweaking and adjusting record and replay bias, level and eq, and made innumerable tests on the recording quality of various blank tapes. As I recall, one of the very best was a batch of Woolworths ferric tapes! The next batch was a disaster. So again, whatever sound right to you is what is right for you. Full stop.

                    OK, so let's move on a bit. What I wanted to show thus far is that, given a reference recording (example 4) we can manipulate it by adding-in some of the characteristics of a typical analogue system and arrive at a slightly different sound. It doesn't matter what we prefer - that's your choice not mine - but it certainly is a different sonic experience. The question is, in absolute technical terms, is it better? Perhaps we should define better. Setting aside emotional subjective factors, I'd look back over the history of recording back to the wax cylinder and say that better fidelity has as a minimum something to do with the reduction in unwanted noises on replay which were not present in the original performance. There are other factors such as wider frequency range, lower distortion and so on, but the path to greater fidelity has a primary goal of reducing unwanted noises.

                    The earliest known recording is from 1878 onto tin foil here. The voice is claimed to be Frank Lambert speaking to us from one hundred and thirty years ago:

                    Example 5:

                    We can reliably assume that it is the sound of a human voice but the unwanted noise is so intrusive that it's very difficult to figure out what is being said. Next came recording by cutting a groove onto a wax cylinder. This a completely mechanical process. The performers sound was funnelled down a trumpet, concentrated at a small chisel which literally cut the groove into the rotating wax. To increase the loudness, the performers had to project their voices and instruments or sit closer to the cutting-horn. Here is a modern session cutting a wax disc. And here is what the playback sounds like:

                    Example 6:

                    We can clearly follow the music, the articulation is tolerable, but there is no high (or low) frequency detail and the accompanying brush-tapping is completely absent because of the low energy in the sound and the inability of an acoustic-only signal to sufficiently power the heavy cutter to follow the fine high frequency detail of the brush sound. And again, the pervasive surface hash obscures all the fine detail in the voice and instruments. Doubtless, this system was hailed as having remarkable, true-to-life fidelity at the time. Read more here.

                    That led to the 78 rpm shellac disk. As mentioned here "Before 1925, all 78s were recorded by means of the artist singing or speaking into a horn [just like the wax cylinder], the power of their voice directly vibrating the recording stylus and thus cutting the wax of the master disc. Collectors call these discs "acoustic" recordings. After about 1925, 78s were recorded by the artist singing or speaking into a microphone and [electrical, valve] amplifier which then cut the master record. This allowed a wider range of sound to be recorded. Records recorded by this process are called "electrical" recordings. Collectors can identify these discs by either by listening or by means of small marks in the record surface close to the label."

                    Here is an example of a piano recording from 1925. I'm convinced that this is an electric recording because of the extended higher frequency range (for a 78 disc) but still we have the very obvious surface noise:

                    Example 7:

                    Now to illustrate a point. If we take the above 78 in example 7 and we remove all the crackles, clicks and most of the surface noise we have a cleaned-up recording. Please compare example 7 and 8. Whilst the surface noise is undoubtedly reduced what I hear in ex. 8 is the addition of a digital-artefact warbling (slightly bathroomy quality) and what appears to be much less 'detail'. Now that's very interesting because in ex. 8, by removing the high frequency noise we've removed the illusion of extended high frequencies in the piano. So ex. 8 sounds duller and less detailed. But in fact, the illusion of more detail in example 7 was a psychoacoustic trick. The surface noises fooled us into thinking that there was more top. There really wasn't. But whatever the technical arguments urging us to remove the surface noise from example 7, personally I'd rather have the illusion of the extra piano brightness.

                    Example 8: - de-noised version of ex. 7

                    Note that the noise-reduction system cannot repair or disguise the distortion in the last notes in both ex. 7 and 8.
                    Alan A. Shaw
                    Designer, owner
                    Harbeth Audio UK

                    Comment


                    • #40
                      Noise and informaton

                      Thank you for the lesson and for pulling together all this fascinating information.

                      Two questions/comments:

                      1. To those who say the demonstration is invalid because it's digitally synthesized vinyl we're listening to, wouldn't the correct response be that the issue here is one of noise levels, and whatever else "real" vinyl may do well, the information loss will be the same (if the noise levels match), because the loss is due to the level of noise, not the medium?

                      2. Is there an analogy to be drawn with Harbeth's RADIAL cone material, in that it reveals more detail, especially low-level detail, because of inherently lower signal loss due to self-generated noise (compared to regular cones)?

                      Comment


                      • #41
                        It's better to have wax outside the ear

                        Absolutely delightfull! I appreciate that piece of history about the wax disc. Plus, I discover the "Boulder Acoustic Society". I really like their sound, more on the original YouTube's video than on the wax disc ;-)

                        It's also interesting to have such chronological demonstrations of different recordings from different methods at different times. We can clearly see recording's methods improving.

                        About examples 7 and 8. I haven't been fooled on frequencies at first and prefer number 8. That's funny, I have some old recordings from the 1930's-40's-50's in my LP collection that sound close to this.

                        Alan, after all, I'm still wondering why do you refuse to call yourself an audiophile? You'll have to explain it to me one day. If you already expressed yourself about this on the HUG, please give me the link. Thank you.

                        Sebastien

                        Comment


                        • #42
                          Track 4 vs Track 8(Example 8)

                          With the risk of getting censured, I have to say I am unable to connect with your last statement, i.e

                          Originally posted by A.S. View Post
                          ....... But in fact, the illusion of more detail in example 7 was a psychoacoustic trick. The surface noises fooled us into thinking that there was more top. There really wasn't. But whatever the technical arguments urging us to remove the surface noise from example 7, personally I'd rather have the illusion of the extra piano brightness........
                          with what I experienced in Track 3 and 4. My perception was track 4 to be with more extended highs. Please note, track 4 was without "noise". So how do you reconcile with your new statement that surface noise fools us into thinking that there was more top.

                          Either, I am very wrong with my perception or artificially induced distortion alters the perception and sound differently than sound recorded with inherent noise. In track 1 what Alan did was to introduce the noise over the original recording making the highs (or extended highs and buzzes) to be drowned with the noise. In the case of track 8 (example 8), when noises were removed the highs too get removed in the process.

                          So is it possible when we remove the noises in track 1 using a similar process as in track 8, then would track 4 sounds duller and less detailed?

                          ST

                          p.s.Off Topic: Ipad/ Apple is not supporting Flash Player and some say that the new html5 standard would make Flash Player obsolete. Maybe, Harbeth need to rethink the use of Flash Player and future compatibility. It has been annoying two months for me that website with Flash Player cannot be viewed in Ipad. Can any IT experts shed some light here?

                          {Moderator's comment: we'll just have to see how web media develops. We settled on Flash because a) it's an Adobe product and totally supported and b) was playable on 95%+ of pcs. c) good video/audio quality. We will make a PDF embedding these examples for you to test on your iPad.}

                          Comment


                          • #43
                            Audiophilia?

                            I don't think one should claim to be an "audiophile" without a rock-solid understanding of how the ear/brain works. My knowledge about that - or indeed about anything - is wafer thin. So it would be laughable to hold myself up as an "audiophile" whilst I'm still learning.
                            Alan A. Shaw
                            Designer, owner
                            Harbeth Audio UK

                            Comment


                            • #44
                              Eric - I should hand the reins over to you and take a nap!
                              Alan A. Shaw
                              Designer, owner
                              Harbeth Audio UK

                              Comment


                              • #45
                                Originally posted by STHLS5 View Post
                                ... I have to say I am unable to connect with your last statement, i.e ... My perception was track 4 (the CD quality example) to be with more extended highs. Please note, track 4 was without "noise". So how do you reconcile with your new statement that surface noise fools us into thinking that there was more top...
                                Ok, we are not comparing like with like.

                                To recap: Tracks 1-4 have basically the same frequency response (bandwidth) plus a you say, added noise on 1-3. And you prefer example 4 which has no added noise and seems to have more top and detail? [And does]. Right? But I said that the addition of noise can trick us into thinking that there is more top in the music - how to reconcile these two observations.

                                What we mustn't forget is that the CD example (no.4, in fact 1-4) have a wide, continuous, extended bandwidth up to 24kHz (I recorded at 48kHz sampling rate). The noise I added is dumped on top of that bandwidth right across the band. And (approximately) that is what we have with example 7: (probably) random, wide band noise perhaps with some emphasis in the higher frequencies. The limitations of the recording/cutting and playback technology on that 78 would have meant that the upper piano harmonics just didn't come through that record/replay process: they just are not there. And we can't put them back or we could make narrow-band performances recorded 80 years ago sound like wide band CD - impossible.

                                So perhaps the 78 disc's audio bandwidth is only 6 or 8kHz. But we're listening on modern wide-band equipment. And we can assume that the random surface noise will extend right up to 20kHz +. So we have an audio gap between the upper edge of the captured piano sound and the full noise spectrum of the noise.

                                That's where the psychoacoustics takes over. Unlike the high quality recordings (ex. 1-4) where there is a wide audio bandwidth with the noise plonked on top, with the 78 we have a narrow band recording with wide band noise superimposed onto it. And that noise in the higher frequencies beyond the limited piano tone is sufficient far away from the piano frequencies that the audio masking process in the brain brain is fooled, and the noise stands out in sharp relief. It seemingly 'brightens' the piano, and seemingly "adds" the missing harmonics which are, in fact, not there on the recording at all.

                                I've take No.8, the de-noised 78 and added some noise to it, with an premphasis towards HF noise. Now we're moving back towards the sound of the original 78 (no.7) with the untreated surface noise. I prefer the brighter tone of No.9 compared with No.8 and after a second or two the obvious hiss does not draw attention to itself. In this example, I've turned the noise on and off to 'brighten' the piano. This trick works because there is an spectrum gap between the missing harmonics of the piano and the bandwidth of the hiss. This is an example I have made in haste ...

                                Example 9: - noise added back in to de-noised example no. 8
                                Alan A. Shaw
                                Designer, owner
                                Harbeth Audio UK

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