What determines "believability of the reproduction illusion"

[PeterA]

Peter,

You are just addressing the classic definition of timbre - frequency response and decays, as I have referred before. However this definition is not enough for sound reproduction - almost all solid state electronics have excellent timbre if we just use these two aspects. Some people referred that electronics can change timbre, and give extraordinary importance to timbre. I think we need to know more about it. What is affecting our perception of timbre and is not timbre?

SET electronics systematically affects timbre, due to its output impedance. Curiously it is high on our "believability" scale.

microstrip, you asked us to define what we mean by the term when you wrote this: "But my ability is secondary to the thread - I would like to read how audiophiles define timbre - let us hope they do not say it is the quality that makes recordings "believable"."

I answered your question, though I did not mention "frequency response". What you ask in this post above in bold is a different question and a better one, though I can not answer it.

 

[ack]

I would also largely agree with Timbre being the most important but not to the exclusion of other important "believability" factors, like dynamics. I would also argue that far more subtle things like phase shifts in a system are the hidden destroyers of beliveability.

FWIW, I exclude presence from the list of things that make the reproduction event _believable_ per se; this attribute, and a few others (like _ultimate_ dynamics, soundstage, etc), belong to what I would consider Excitement. Presence adds an additional level of excitement, and the lack of it retracts little from it... Again, this is not different than in a concert hall: you sit up front, the presence is overwhelming and exciting; you sit in the back, you don't feel the presence, but the experience is still exciting, just not as much. Either way, both experiences are believable. As an example in high end audio, horns give me a great sense of presence and ultimate dynamics, and that's exciting; and if they were to combine it with accurate timbre they would be at the top of my list... but the ones I have heard don't, so I have not personally experienced a horn-based system that's believable, though they have been exciting. Similarly, I would say the same things about soundstage: so what if it's a little smaller, or a little larger - I don't think of the "soundstage" when I am in the concert hall... so secondary as well, and part of Excitement.

 

[DaveC]

SETs are high, in the right system, on believability because the nature of the distortions they make is sympathetic with the ear/brain's self-generated harmonics and masking that benefits low order distortions far more than high order distortions. Timbre is therefore perceived as more natural with a SET...a good one thta is. What do I mean by a good one? For starters it has to have a very well thought out robust power supply because there is no negative feedback to "clean-up" distortions from sloppy application of power. Secondly it MUST have a sufficiently larger transformer so that core saturation is not an issue up to at least the rated power. Surprisingly, this sin is committed by even very expensive SETs and Push/pull amps. Yes, Push/pull tube amps are just as gulity of these sins as well. Why do companies skimp? Good output iron is pretty expensive and usually the most expensive single component in a tube amp. It is also harder to get good high frequency extension from a large core output transformer. A good SET will have an output transformer that is low distortion in the bass and extension to well beyond 20Khz. If it doesn't do this, then the believablilty factor will be lower just like if the tube operational points are drifting around due to an inadequate power supply.

I agree wrt power supply and OPTs, one nice thing about SET power supplies is the filter after the rectifier uses lower value capacitors so you can ditch the electrolytics and use film caps. I use Clarity TC series caps in my own tube gear, the difference vs electrolytics is pretty big.

Another key many SET designers miss is the driver section, the typical single triode driver is the source of a lot of distortion and typical "tube sound". A better driver with less distortion is capable of making a SET amp sound very precise and accurate, my own SET amp has sounded a lot less "tubey" than many SS amps. Interestingly, many preamps use decent circuits that work well for SET drivers but it's so rarely applied to an actual SET amp because of the additional complexity. Also, it helps A LOT if the driver section has it's own power supply, there are issues associated with using the output tube's PS for the driver circuit too.

Overall, I think SET + an efficient speaker can make for a very believable system, moreso than most lower efficiency systems that measure far better. For simple music like female vocals with sparse acoustic accompaniment, SET + a good single driver is almost unbeatable.

 

[PeterA]

FWIW, I exclude presence from the list of things that make the reproduction event _believable_ per se; this attribute, and a few others (like _ultimate_ dynamics), belong to what I would consider Excitement. Presence adds an additional level of excitement, and the lack of it retracts little from it... Again, this is not different than in a concert hall: you sit up front, the presence is overwhelming and exciting; you sit in the back, you don't feel the presence, but the experience is still exciting, just not as much. Either way, both experiences are believable. As an example in high end audio, horns give me a great sense of presence and ultimate dynamics, and that's exciting; and if they were to combine it with accurate timbre they would be at the top of my list... but the ones I have heard don't, so I have not personally experienced a horn-based system that's believable, though they have been exciting.

ack, I place greater importance on the notion of Presence. In my experience, a sense of presence has everything to do with "believability" in a home audio system. Of course, timbre has to be accurate, but if the system sounds flat, or images are undefined or wrong, in scale or location, or there is no dimensional, palpable impression of the performers in front of the listener, then it is just not believable to me. The sound also must give the impression of leaving the plane of the speakers and come out to fill the listening space. I have heard systems with accurate timbre but no presence, and they have not sounded believable to me. They may produce good stereo sound, but that is about all. They will not engage me emotionally, and although I appreciate the accurate timbre, I start to listen for more as if something is missing. I listen to the sound but don't get lost in the music.

I have compared the sound of an opera, heard over four consecutive mornings and afternoons from the front edge of the orchestra pit mere feet from the conductor to the sound later during those same four evenings heard from the front row of the director's box at the Vienna State Opera house. The sound was surely different, and I agree the level of excitement changed, but there was no lack of presence from the seats in the back of the hall in the second balcony at center. The presence was still there in abundance, it was just that my perspective or relationship to the performers on stage was different. The shape, scale, location and ratio of direct to reflected sound changed, but there was no mistaking the vivid presence of the performers in the hall. The listening perspective was just different.

Frank and DDK wrote about the "full effect" while listening to their audio systems. If a system has presence, as well as the other necessary ingredients for believability, then that system will have it as one walks around the listening room. In the most successful systems, I find that the degree of presence and believability do not change much as one moves around. This is similar to the experience in a concert hall. The sound is always believable and is always "present", but if a system lacks this presence, then for me it is not believable.

Here is a qualification: One can argue that if the timbre, plus volume and dynamics, of a system playing a recording of a piano, is accurate, then the system will reproduce the sound of a piano convincingly as heard outside of the room, down the hallway. That is true, and one may "believe" that it is a real piano being played out of sight. So, perhaps that is enough for "believability". But, for me the stakes are higher when seated in the listening room with the system, as they are while seated in a concert hall. I am after emotional connection to the music, and this is elevated when the system has both believable, accurate, timbre and also a sense of Presence.

 

[microstrip]

microstrip, you asked us to define what we mean by the term when you wrote this: "But my ability is secondary to the thread - I would like to read how audiophiles define timbre - let us hope they do not say it is the quality that makes recordings "believable"."

I answered your question, though I did not mention "frequency response". What you ask in this post above in bold is a different question and a better one, though I can not answer it.

My concern is that we are transposing the usual definitions and experiences of timbre in real life to electronic signals, and there we can not find any equivalence. Interestingly morrycab addressed a relevant fact - he doesn't not expect that we will be able to identify some types of timbre differences from recordings unless we are familiar with life instruments.

Soundlab's are very clear showing timbre differences, particularly in dissecting the rising edge of notes or the differences between amplifiers. It is one of the reasons I am so interested in this subject, as I am in the process of trying different amplifiers with them.

 

[PeterA]

My concern is that we are transposing the usual definitions and experiences of timbre in real life to electronic signals, and there we can not find any equivalence. Interestingly morrycab addressed a relevant fact - he doesn't not expect that we will be able to identify some types of timbre differences from recordings unless we are familiar with life instruments.

Yes, I agree that that is an important point. That is why in a past digital thread about the NADAC or about what matters in reproduction, proponents argued that "all we have is the recording" so reproducing that accurately should be our priority. I made the under appreciated comment that we also have our memories. That is, we remember what instruments sound like based on our experiences with them from our past. We compare those memories to the sound we hear from systems in order to assess how accurate the reproduction is. This surely includes are perception of accurate timbre.

 

[ack]

ack, I place greater importance on the notion of Presence. In my experience, a sense of presence has everything to do with "believability" in a home audio system. Of course, timbre has to be accurate, but if the system sounds flat, or images are undefined or wrong, in scale or location, or there is no dimensional, palpable impression of the performers in front of the listener, then it is just not believable to me. The sound also must give the impression of leaving the plane of the speakers and come out to fill the listening space. I have heard systems with accurate timbre but no presence, and they have not sounded believable to me. They may produce good stereo sound, but that is about all. They will not engage me emotionally, and although I appreciate the accurate timbre, I start to listen for more as if something is missing. I listen to the sound but don't get lost in the music.

I have compared the sound of an opera, heard over four consecutive mornings and afternoons from the front edge of the orchestra pit mere feet from the conductor to the sound later during those same four evenings heard from the front row of the director's box at the Vienna State Opera house. The sound was surely different, and I agree the level of excitement changed, but there was no lack of presence from the seats in the back of the hall in the second balcony at center. The presence was still there in abundance, it was just that my perspective or relationship to the performers on stage was different. The shape, scale, location and ratio of direct to reflected sound changed, but there was no mistaking the vivid presence of the performers in the hall. The listening perspective was just different.

Frank and DDK wrote about the "full effect" while listening to their audio systems. If a system has presence, as well as the other necessary ingredients for believability, then that system will have it as one walks around the listening room. In the most successful systems, I find that the degree of presence and believability do not change much as one moves around. This is similar to the experience in a concert hall. The sound is always believable and is always "present", but if a system lacks this presence, then for me it is not believable.

Here is a qualification: One can argue that if the timbre, plus volume and dynamics, of a system playing a recording of a piano, are accurate, then the system will reproduce the sound of a piano convincingly as heard outside of the room, down the hallway. That is true, and one may "believe" that it is a real piano being played out of sight. So, perhaps that is enough for "believability". But, for me the stake are higher when seated in the listening room with the system, as they are while seated in a concert hall. I am after emotional connection to the music, and this is elevated when the system has both believable, accurate, timbre and also a sense of Presence.

For one, I just don't agree with the highlighted statement - there is no presence when sitting at Symphony Hall's rear-left and rear-right orchestra seats, for example; it's even worse at Tanglewood; but the experience is still believable; try it. I just do not buy that every seat in every hall offers presence, therefore, presence is not part of what makes things believable to me; it just adds Excitement, but on the other hand, there is nothing wrong in seeking Presence as well. In fact, I'd rather be on the conductor's podium! So nothing wrong with your definition of believability either, but I don't agree that a system w/o presence won't be believable. For example, I have heard highly believable systems (per my definition) - like the Magico M5s, driven by Nagra tubes - which render everything far into the stage, with no real presence [performers not in front of me], and they were spectacular in their own right; a lot of folks like that sound.

You also brought up an interesting counterpoint in your last sentence: what is "enough" for believability; and you mentioned perhaps timbre plus volume and dynamics. I just focused on what is the TOP attribute and what comes after, but not what's enough. I have not thought about what's "enough".

 

[DaveC]

Has anyone heard a high-performing system that doesn't have "presence"? It seems like this just happens when other things come together...

Presence from outside the room when you can't see the speakers is also interesting, how live the music can sound... imo it is somewhat important and has to do with the speaker having an even power response since you're not hearing any direct sound, but also that it can play at realistic SPLs, have extended frequency extension on both ends and proper dynamics.

 

[Al M.]

For one, I just don't agree with the highlighted statement - there is no presence when sitting at Symphony Hall's rear-left and rear-right orchestra seats, for example; it's even worse at Tanglewood; but the experience is still believable; try it. I just do not buy that every seat in every hall offers presence, therefore, presence is not part of what makes things believable to me; it just adds Excitement, but on the other hand, there is nothing wrong in seeking Presence as well. In fact, I'd rather be on the conductor's podium! So nothing wrong with your definition of believability either, but I don't agree that a system w/o presence won't be believable. For example, I have heard highly believable systems (per my definition) - like the Magico M5s, driven by Nagra tubes - which render everything far into the stage, with no real presence [performers not in front of me], and they were spectacular in their own right; a lot of folks like that sound.

You have a point here!

I crave presence for emotional involvement, but in some live situations/seats in the hall there just isn't much of it.

Same holds for ultimate dynamics, incidentally. I want the best dynamics, but often in the concert hall, while dynamics are always very good, there just isn't the ultimate 'jump factor'. This holds especially when seated a bit further from the stage.

Also, I have found that often live dynamics, especially on orchestral music, seem somewhat 'diluted' by the sheer scale of the sound (yet this is not necessarily always the case). I have sometimes wondered if exciting orchestral dynamics at home are not partially an artifact of the smaller scale.

On the other hand, dynamics of jazz ensemble in a small club seem at times enhanced by the sheer scale of presentation.

 

[ack]

You have a point here!

I crave presence for emotional involvement, but in some live situations/seats in the hall there just isn't much of it.

Same holds for ultimate dynamics, incidentally. I want the best dynamics, but often in the concert hall, while dynamics are always very good, there just isn't the ultimate 'jump factor'. This holds especially when seated a bit further from the stage.

Also, I have found that often live dynamics, especially on orchestral music, seem somewhat 'diluted' by the sheer scale of the sound (yet this is not necessarily always the case). I have sometimes wondered if exciting orchestral dynamics at home are not partially an artifact of the smaller scale.

On the other hand, dynamics of jazz ensemble in a small club seem at times enhanced by the sheer scale of presentation.

Precisely. Another classic example is solo violin, or any soloist for that matter - especially soprano. Where I like to sit, up in the second balcony, I struggle to make sense of the soprano's lyrics; she is so far away into the stage and certainly not present in front of me, yet it's still all real. Contrast with an up-close orchestra seat, where she's right in front of you, quite present and also very real. Contrast yet again with a tenor or a bass - his voice fills the concert hall much more than the soprano and the illusion of presence is elevated, but still he's also not quite right there in front of me up in the balcony, yet very real.

 

[fas42]

Hello ack

Agreed but there has to be a lot more to it than that as far as making something sound believable. After all you can easily distinguish differences between instruments and recognize singers voices on many meager systems. I can do that in my car. So even of you can get the timber correct enough to know who is singing or what instrument is playing that does not make it believable.

Rob

The human voice is a perfect test sound in this regard - from a lifetime of listening to this type of acoustic information we instantly can detect nuances in the quality of it. Yes, we can recognise someone we know over a terrible communication link - but that is miles from being able to amplify that electrical signal to realistic SPLs, and being fooled if we are not aware of the source of the sound.

I have a number of test CDs that I use expressly for this - on any system you know who is singing, except it becomes like a caricature on poor playback. On better ones you appreciate more and more the "technical" quality of how the person is singing, their craft - but only on a convincing system does that sound became a 100% human voice, in the room - spooky real, are the sort of terms people use to describe this. Just the slightest hint of artifacts in the reproduction, and we dismiss the voice as being valid, it's now obviously just a recording ...

Billie Holiday, and Odette are two classic voices for this - the fact that the recordings are not pristine makes the job of the system even harder; it's an immediate tick, or cross when picking the competence of a setup using this material.

 

[fas42]

Here is a qualification: One can argue that if the timbre, plus volume and dynamics, of a system playing a recording of a piano, is accurate, then the system will reproduce the sound of a piano convincingly as heard outside of the room, down the hallway. That is true, and one may "believe" that it is a real piano being played out of sight. So, perhaps that is enough for "believability". But, for me the stake are higher when seated in the listening room with the system, as they are while seated in a concert hall. I am after emotional connection to the music, and this is elevated when the system has both believable, accurate, timbre and also a sense of Presence.

Yes, this is the two sides of the coin - and is the much harder thing to get right. The believability has to be there at the other end of the house, and, when sitting directly in front of, merely feet away from the speakers. There are systems that can do one or the other, but doing the both at the one time, meaning no change of the volume control, is far trickier to make happen. The mention of horn speakers getting the excitement factor in spades, but failing to convince when standing right at the mouth of the beasts, is a perfect example of the system being halfway there - it has dynamics, but not correct tonality; there is too much obvious distortion, in ASA terms, when listening at a spot where SPLs are realistic.

 

[stehno]

Pretty interesting how we seem to over-analyze even the simplest of questions.

I wonder. If my brain is analog and the Supreme Being is digital, would that make my soul the DAC?

 

[fas42]

Same holds for ultimate dynamics, incidentally. I want the best dynamics, but often in the concert hall, while dynamics are always very good, there just isn't the ultimate 'jump factor'. This holds especially when seated a bit further from the stage.

Also, I have found that often live dynamics, especially on orchestral music, seem somewhat 'diluted' by the sheer scale of the sound (yet this is not necessarily always the case). I have sometimes wondered if exciting orchestral dynamics at home are not partially an artifact of the smaller scale.

On the other hand, dynamics of jazz ensemble in a small club seem at times enhanced by the sheer scale of presentation.

I would suggest that "jump factor" for live sound is determined in large part by the nature of the echoes. "Big" sound in a small space bounces around and around, and our brain finds that "exciting", there is so much happening in the sound field, and our minds get a kick out of it. But, the quality of the sound from the speakers of an audio system, and thence those of the echoes has be 100% OK, in ASA terms, or we feel overloaded by the sound - it's no longer exciting ...

 

[PeterA]

Has anyone heard a high-performing system that doesn't have "presence"? It seems like this just happens when other things come together...

Presence from outside the room when you can't see the speakers is also interesting, how live the music can sound... imo it is somewhat important and has to do with the speaker having an even power response since you're not hearing any direct sound, but also that it can play at realistic SPLs, have extended frequency extension on both ends and proper dynamics.

I have not heard a high-performing system that does not also have "presence". For me, a sense of presence is required to be high performance. However, I have heard systems that have a sense of presence but, they are not what I would describe as "high-performance" systems. The problem is that they can work well with the room to provide a palpable, dimensional, sound with realistically spaced and scaled instruments, a good, large stage, etc. but there is something else missing, perhaps a higher level of resolution, a balanced bass response and extension, or driver integration. A lot also depends on the type and scale of the music and on the recording quality. At least on my system, it is easier to convincingly reproduce a well recorded small ensemble than it is a large scale symphony, so, depending on the music, my system has presence but some might argue that it is not high performance, because of the limitations of my small speakers and the size of my room.

I have also heard systems that have the potential to be high-performing, but the room limitations or how the system is set up, prevent them from achieving high level sound.

If "other things come together", as you write, then high-performing systems should also have Presence.

 

[fas42]

Just came across this thread by Gary, of the "fun" system he set up - with mini-monitors and huge tube amp, http://www.whatsbestforum.com/showthread.php?20857-Genesis-at-T-H-E-Show-Newport-2016. This is exactly the sort of sound experience I work on getting, with the 'bizarre' visual mismatch with what's in front of one compared to the sound being heard ..

 

[Al M.]

I would suggest that "jump factor" for live sound is determined in large part by the nature of the echoes. "Big" sound in a small space bounces around and around, and our brain finds that "exciting", there is so much happening in the sound field, and our minds get a kick out of it.

It does not bounce around with proper room treatment. But hey, I forgot, you find room treatment unnecessary....

 

[fas42]

It does not bounce around with proper room treatment. But hey, I forgot, you find room treatment unnecessary....

What I always after is convincing, or believable sound - as has been expressed many, many times, something like a real saxophone played in a very dead room, or a very live room will sound very different, the acoustic makeup of the sound as registered by your ear will be differ greatly - but the fact that the instrument is a living, breathing object, acoustically, is unmistakeable, both times ...

Peter said

I have also heard systems that have the potential to be high-performing, but the room limitations or how the system is set up, prevent them from achieving high level sound.

If "other things come together", as you write, then high-performing systems should also have Presence.

and that's exactly how I see it - with the one variation being, that "room limitations" will prevent believability, is not the case.

Large scale symphonic requires a higher degree of competence, the ability to reproduce climaxes effortlessly, while still rendering nearly inaudible passages in that piece convincingly - this is not trivial to achieve ...

 

[Steve williams]

Frank

It seems to me that you are always chasing a moving target and have never found that perfect sound.

 

[fas42]

Steve, I have heard competent sound many times - but I have to "pull out all stops to do it"; things like shutting down the house I'm in electrically, switching off all wireless devices in the area; warming up for long periods of time. IOW, I can't just walk in first thing in the morning, switch it all on from cold, do nothing else and get brilliant sound within 5 minutes or so ... it's never happened for me that way.

The moving target is getting believable sound in exactly that scenario; in the midst of a home working normally, whenever I want to - that's proved very elusive. Every now and again, I push everything to the n'th degree, just to check, confirm everything is in good shape for me to get that quality - but the real "product" needs to be in the form equivalent to a modern, well engineered car; it should work totally competently, completely unassisted by any fiddling, just by turning a key or equivalent and proceeding ...