Getting a 3D holographic presentation from 40.1

[Kathylim]

I recently listened to a toys for boys speakers and it was impressive to say the least. It was played in the living room and not only was the presentation 3D with the musicians seemingly located in the room but also of the right scale i.e the piano doesnt sound like it is 20 feet big. Best, musical as well.

I have a musical system driven by a USD100 (15watt) amp but want to extract the full potential of the 40.1. Is that wrong?

The following is extracted from the Harbeth site on the 40.1 .......

"The speaker is completely transparent and paints a 3D holographic sound stage which is totally addictive for its neutrality."

The 40.1 can deliver the scale of a live performance but how can I achieve a 3D holographic sound? is it a matter of placement or room acoustics?

[hifi_dave]

I can certainly achieve that in my demo room with a range of electronics. Placement and room acoustics play a large part in the process and my present room is far from ideal. I am planning an extension in the Spring but until then I have to struggle on with the help of some home made absorbers behind and to the sides of the speakers.

The imagery is very good indeed but the 3d effect is better with some electronics than others. Of course, best results are from a good TT combo.

[A.S.]

...I have a musical system driven by a USD100 (15watt) amp but want to extract the full potential of the 40.1. Is that wrong?

Are you sure that it's an ever-achievable sonic objective with an amp that falls below the 'ideal' minimum specification we give for the M40.1?

If you refer to the M40.1 page on the Harbeth brochure here you'll see that I mention 50W, not 15W, as the minimum amp spec for what is a large three-way system. If the amp is priced at $100, one can only guess at the material cost and you could probably buy a few beers for the same component outlay. I'd strongly suggest that you invest in an amplifier that's more of a natural match to this flagship speaker!

[Kathylim]

Alan, thank you for your reply. I am familiar with the recommended minimum specification.

The amp is a Sansui Au101 made in 1974. I bought it 2 years ago for USD100 and in good condition (recapped). I may appear to you that I may have taken the "any decent amp will do" doctrine to the extreme but I can assure you, it is a decent amp.

I settled with the Sansui in my system as it is the only amp which gives me glimpses, though faint, of a 3D presentation from time to time on certain recordings. As I have not been able to achieve the ideal presentation from the 40.1 it came down to just enjoying the music which the Sansui does quite well but has always left me wondering whether the 40.1 is capable of more. Though 15 watts, it allows me to play most music even rock at spls loud enough to cause hearing damage, if for an extended time.

I have tried the, Leben CS600 (32watts),LFD (60 watts), Exposure 2010s (55 watts) and the Pathos Logos (110watts) with the 40.1. All have not been able to deliver that 3D sound. With the exception of the Sansui, the presentation from the other amps is recessed/flat against the wall.

I believe Dave will attest to some of the mentioned amps being of decent quality and based on his reply, has tried some of them, with success.

Based upon the foregoing, do I discount the amp? but why is the Sansui able to deliver some of the desired effects but not the rest?

[Hwveldhuis]

100 USD must be a joke or a typo...

Grt. Mike

[Kathylim]

Not a typo nor a joke. But a joke would be say having owned an Audio Research CD7, Ref 3, Vt100 mk iii and a Pass Labs 350.5x and not getting the music nor the ideal presentation.

[A.S.]

Alan, thank you for your reply. I am familiar with the recommended minimum specification.

The amp is a Sansui Au101 made in 1974. I bought it 2 years ago for USD100 and in good condition (recapped). I may appear to you that I may have taken the "any decent amp will do" doctrine to the extreme but I can assure you, it is a decent amp....

Clearly there is a strong emotional bond between you and this nearly forty year old mid-market amplifier. I respect that. But can you see the irony of the situation? You are seeking fast track to the holy grail of two channel audio reproduction (a 3D sound stage) but your route there is in a Morris Oxford.

Common sense tells me - and I know nothing whatever of your amplifier - that even in the slowly-evolving world of audio amplifier technology, a contemporary mid-price amp will surely outperform a tired forty year old specimen. There are so many reasonably priced modern examples to chose from that are discussed here on HUG. And they need not cost a fortune. If there was absolutely no progress in amplifier design over the past forty years then we'd all be using classics, and the amplifier industry would have closed down long ago. Modern amplifier designers have the audio measuring tools, track layout CAD and a generation of skills at optimising circuitry that were only a science fiction dream back then. And they've used them intelligently: so intelligently that the differences between modern amps are tiny.

My honest opinion is that you are never going to reach your goal unless you take a cold, hard look at the necessary investment you need to make in your entire system to match the performance potential of your class-leading Monitor 40s. And 15W power for the M40.1 is far below my recommendation.

[Kathylim]

But can you see the irony of the situation? You are seeking fast track to the holy grail of two channel audio reproduction (a 3D sound stage) but your route there is in a Morris Oxford.

There are so many reasonably priced modern examples to chose from that are discussed here on HUG. And they need not cost a fortune.

My honest opinion is that you are never going to reach your goal unless you take a cold, hard look at the necessary investment you need to make in your entire system to match the performance potential of your Monitor 40s.

After the many paths I have travelled, I am surprised there is even one...i.e a fast track to the holy grail.

Well the Sansui resides in my system simply because the other mid market amplifiers I have tried and mentioned in my earlier post have not produced the desired results. I am now confused as to what constitutes the necessary investment to my entire system if I am to discount the other mentioned amps and of course the Sansui.

[Heretic]

Kathylim, you may borrow my Krell amp anytime... Full 150 "Modern" Watts all at your disposal. Its a Krell of the no-nonsense Dan D'agostino era. Then please do share back the findings here?

I am fully aware of the esteemed Mr. AS refraining from giving any endorsement to any amp brand, but at least it might pass through his seal of approval (a silent nod would suffice) to having 40.1s driven by a 150 Watter...

[Don Leman]

A picture of your setup would be helpful to those wishing to provide suggestions.

[ryder]

I am not too sure on the suggestion of making the necessary investment to match the performance potential of the class-leading Monitor 40s and to achieve Kathylim's goal. The OP has highlighted earlier that he had tried some of the modern amps that fit the M40.1's criteria (>50W), and to his ears these amps do not sound as convincing as the 15W vintage Sansui, and they do not deliver the 3-D soundstage well enough.

Considering Harbeth's take on negligible or zero sonic differences between amplifiers, I cannot see the reason how a necessary investment in modern amplification will resolve the OP's issue due to Harbeth's philosophy in the topic of amplifier.

{Moderator's comment: how are we supposed to progress this discussion if the user is intentionally ignoring our recommendation? We say minimum 50W. The Sansui is rated at 15W. Consult the brochure and you will see the only Harbeth that we recommend a 15W amp with is the smallest Harbeth. The P3ESR. The biggest Harbeth *needs more amp power* because it demand more power due to three drive units plus complex crossover. This issue must be resolved first.}

[A.S.]

...I am fully aware of the esteemed Mr. AS refraining from giving any endorsement to any amp brand, but at least it might pass through his seal of approval (a silent nod would suffice) to having 40.1s driven by a 150 Watter...

150W available to drive M40.1 and a first class amplifier brand reputation says to me that this is home setup is likely to deliver a great sonic experience with oodles of power reserve for those thrilling climaxes.

Consider this imperfect analogy: the (incandescent) light bulb lighting your room may well have a 150W rating. That will fill every corner of your room with bright light. Remove that bulb and fit a 15W (one tenth of the power) and what then? The room is miserably dark: there are deep shadows in the corners. You cannot even read. You are stumbling around in the gloom. Why would you want to live like that when you are advised that 50W is necessary to throw the minimum light into the environment?

I don't just dream-up the minimum amplifier requirements for the fun of it. I am aware that if I suggest a minimum amplifier power rating that's too high, those customers with smaller amps may be frightened off Harbeth and select another brand which emphasises higher efficiency. Conversely, I am aware that to produce a reasonable sound pressure level that gives a satisfying quasi-real life experience a certain amount of power is necessary. So the minimum power amp ratings I've listed in the brochure are really minimums bearing in mind that you should interpret the manufacturer's amplifier power outputs with a very large degree of scepticism. Outside the lab, many amps are unlikely to be able to deliver their rated power on music when driving real-world speakers.

What tube fans don't realise (and I've heard SHL5s driven by 300B 7W tubes and sounding good) is that when you connect a 'scope across the 7W amp's output terminals and look at the music waveform, it shows significant clipping. And that clipping may be present for 25%, 50% or even 100% of the time. That shouldn't be a surprise at all: 7W is a minuscule amount of power. So how is it that those users are satisfied with what they hear? Simple - the tube amp (and I stress this, the situation with a transistor amp is totally different) clips is a sonically benign way. In other words, it runs out of power in a way which does not immediately reveal itself to the human ear. It doesn't sound hard or coarse when clipping: it sounds fat and warm. And that's all part of the magic sonic experience of small (tube) amps.

So - rule of thumb: give yourself a fighting chance of high fidelity sound at home: have a sensible amount of amplifier power available at all times.

[delgesu]

i drive my 40.1 with very old but completely refurbished naim 135 mono´s (rated 75 watt/8ohms , 120 watt / 4 ohms). the sound is perfectly projected into the room. yes, one can call it 3D, if you want. but generally i think, "3D sound" is only possible, if the record allows for it. most of the times it is 2D due to multi-miking or whatsoever.

in my room sound is widely spread between and behind the 40.1s. perfect, in one word.
far more interesting for me is the delicacy of tone color. nobody is more realistic in this field than Harbeth.

best,
delgesu

[Hwveldhuis]

Hi Kathylim,

First of all my reply regarding the 100usd wasn't very thoughtful, my apologies. The cool thing is: many, many years ago I owned a Sansui 101. It was my first stereo amplifier! Really enjoyed the sound. Didn't realise this, but after rereading this thread.

I recently bought Monitor 30's (you can read my story in the recent Harbeth newsletter). I have listened to them on various amplifiers, with many different sources. They really grow on you after listening for a longer period. 50 watt is mandatory, so why not get a decent amplifier and use it for at least 2 weeks?

For what's worth it: I use an Accuphase 350, 100 watt neutral 3d energy ;-).

Grt. Mike

[STHLS5]

Hi Kathy,

If you experience *a better sound with a under powered 15 watter amp for your M40.1 then you are having a speaker that is far too big for your listening area. Try the smaller Harbeths. And you are not the only one complaining about difficulties getting good sound from big *speakers. Another friend of mine living in your neighborhood driving another large speakers having the same difficulties. *I am beginning to suspect the design of the houses in area may not be ideal for big speakers unless you want to add large quantity of absorbers and other room treatment.

ST

[Kumar Kane]

I have tried the, Leben CS600 (32watts),LFD (60 watts), Exposure 2010s (55 watts) and the Pathos Logos (110watts) with the 40.1. All have not been able to deliver that 3D sound. With the exception of the Sansui, the presentation from the other amps is recessed/flat against the wall.

With all but one of the above exceeding the 50w spec, and all of them known to be more than just competent, how come no one is talking to the quoted state of affairs?
Perhaps it is a question of speaker/listener positioning. I don't know about 3D and what exactly that means in the audio context, but I get a decent, defined sound stage out of my C7s when I am sitting closer to them than they are to each other. That isn't the usual listening positioning dictated by the room, which is a lot further away from the speakers. From there I get very good music, but a wall of sound, one can't locate different instruments in different places as one can from closer. Given that most speakers set ups at home are usually a domestic issues driven compromise, I am quite ok with that. My guess too is that the speakers would need to be placed significantly out into the room to get the best sound stage from them, at least up to 5-6 feet away from any wall.

[Kathylim]

I thank you all for the sensible responses with none of the "why obsess over the sound"..."revel in the music" or "just use any decent amp...they are all the same", which some espouse. It would have been infuriating to read such comments when I have tried several amps, both budget and of greater value and still not getting the 3D presentation which I am now told the 40.1 is capable of. Such comments say I belong on a psychiatrist couch and not on my home couch, if I aspire for more from the flagship.

If anything, Alan is correct, the subject on amps has a life of its own. I eschew the matter but here we are. I thank you for your views on tube amps and will try others above the recommended specification, befitting the 40.1.

Ryder - It appears, amp and size does matter after all, contrary to opposing views.

To the moderator - I am not intentionally avoiding your recommendation to prevent this matter from progressing. I have tried tried the Leben (32watts), LFD (60 watts), Exposure (55 watts), Pathos Logos (110 watts) but I have not suceeded in getting the 3D performance with any of the mentioned amps. I will unpacked them from the store and try them again.

delgesu - I have the CB135 mono blocks/32.5 pre (with the Avondale card) and a hicap but I have discounted them as they are old and need to be serviced.

Don - I will also take some pictures of my system and of the listening area and will post them for views after I have re-tried the amps and others in excess of 100 watts but without headway.

Heretic - may take you up on your offer to try a 150 watt amp. Thank you.

Hwveldhuis - no offense taken. The Sansui is very enjoyable. I had it in my office before with the P3ESR.


While room acoustics and placement may be critical factors what still nags at me is the ability of the Sansui to let me have brief glimpses of a 3D presentation and which projects the sound away from the back wall, between the speakers and the wall when all the others amps dont. Anyway we shall re-visit the issue after I have tried the other amps.

[Gan CK]

To begin with, i am rather (or very) surprised that the OP found the Sansui to have a nice 3D sound as from memory i never found it to be the case. I owned a couple of popular Sansui Solid State amps from late 80s to early 90s but never found them to be outstanding at all. Yes they had loads of power & kick but they were also rather uncouth & tonally flat.

I had the huge & heavy flagship AU-919 integrated pitted against puny amps like Arcam Alpha, Cyrus 1 & Creek 4140 & i felt those puny british amps to sound much more musical, sophisticated, transparent & posessing superior tonal attributes. There was totally no comparison! Also compared other Sansui integrateds like AU-5500, AU-8500 & a few others with those puny british amps & the results were the same.

The puny Cyrus 1 (only 30wpc) was even pitted against a 45kg Pioneer receiver (300wpc) & the Cyrus beat the Pioneer flat to the ground. Perhaps this AU-101 is different from those i had before. Or perhaps it has been heavily modded before.

[A.S.]

... I thank you for your views on tube amps and will try others above the recommended specification, befitting the 40.1.... While room acoustics and placement may be critical factors what still nags at me is the ability of the Sansui to let me have brief glimpses of a 3D presentation and which projects the sound away from the back wall, between the speakers and the wall when all the others amps dont...

Of course, we must remember that whatever technical issue underpins that mystical "3D" experience you write about (and genuinely believe in), it is unlikely to be a characteristic of the amplifier - indeed, any amplifier. Amplifiers, to the amazement of many I'm sure, are really dumb. They are as basic a piece of technology as you can get. All they have to do - yes all they have to do - is magnify the incoming source signal by perhaps 20-100x and present that on the output terminals to drive the speakers. That's all. Nothing more and hopefully nothing less. As Peter Walker of QUAD so rightly said, the perfect amplifier is 'a straight wire with gain' (gain means amplification).

So, is it technically probable that this exceedingly simple device could take the incoming audio signal, magnify it and regardless of the owner's taste, the music, the recording, the room or even the appropriateness of messing around with the sound, add a "3D" effect? No. Something else is going on here.

An example that's so vivid. In the early-mid 1970s my parents had a B&O colour TV - early days for the technology. To my young eyes, this set in its beautiful cabinet truly seemed to have a 3D picture with real, palpable depth; football matches drew you in. My friends parents colour sets had over saturated, flat 2D pictures with absolutely none of this 3D effect. It made such an impression on me that here we are, nearly forty years on, discussing this mysterious effect. It took me about twenty years to understand why such a crude, early TV could have created such a vivid impression in my young mind, one which if I were to see the set today, I'm certain I wouldn't recognise. It was, as these things so often are, a trick bring played on the observer. The TV picture could never be better than the camera that captured the image or the transmission system that delivered it to my home. And the video camera technology of the day was extremely poor. The reason for this 3D illusion was that the shadow mask of the CRT fitted to the B&O had a rather coarse grid (through which the electrons were fired onto the tube face) and this grid in effect sharpened the edges of the electron beam reducing splashing onto out-of-grid adjacent phosphors. In addition, judging by the massively complex circuitry of the set, the engineers had thrown lots of technology to sharpening-up the tuner performance, very fine adjustment of pincushion and other geometry issues and taken as a whole, the picture was, for the day, really crisp.

But that was nothing more than an illusion. Seen today, it would be a joke. But it's interesting how these experiences stick in the mind. Whatever mental cues are triggered in your brain to give this occasional sonic 3D illusion, I am completely confident another amplifier will, in the right mental circumstances also generate. It must in truth be something to do with the recording, not the reproduction.


P.S. Amazingly I found a picture of the set .....

>

[A.S.]

...So, is it technically probable that this exceedingly simple device could take the incoming audio signal, magnify it and regardless of the owner's taste, the music, the recording, the room or even the appropriateness of messing around with the sound, add a "3D" effect? No. Something else is going on here....

Whilst shaving and mulling over this 3D conundrum of how a 15W, thirty year old (Sansui) amplifier could give you this '3D' sonic effect you mention I may have the answer. It could indeed be the amplifier that's responsible. The clue is in the chronic power mismatch between the amp (only 15W at best) and the minimum recommended for the M40.1 (50W).

In my previous post I talked of my experience as a boy with the B&O colour tv and how the design of the CRT tube (and driving electronics) gave the illusion of a super-sharp, 3D picture, at the time. Technically, what the gauze mesh across the front of the tube did was to apply a 'high-pass electro-mechanical filter'. In other words, to sharpen the edges of the images by inhibiting blurring in the tube, or indeed, even reducing the previous blurring of the picture in the camera/transmission system. A good explanation of the effect of 'sharpening' in didital photography can be found here. See how a little sharpening applied to the edges of the image makes it stand out against the background?

Here is my theory then concerning the 15W Sansui. I suspect that it is occasionally clipping. You may not even be aware of it - but 15W maximum power available to drive M40.1 is almost guaranteed to clip at least some of the time. The clipping, if benign, that is, not prompting you to leap up and adjust the volume downwards, is generating fast-edge transients, and those transients in effect subjectively sharpen the edges of the music giving you this 3D effect. That could be proven by attaching test equipment to the amp and measuring its real-world behaviour driving a speaker not a test resistor in the lab.

My guess would be then that you only experience the '3D' effect when playing at medium to high levels (hence clipping) on wide-range music and never at low levels or on music of limited audio bandwidth which demands little power and avoids clipping.

Just a thought.