How audible is distortion?

[amirm]

Is it not the case that the room's response at higher frequencies also tells a human what its response will be at lower frequencies? i.e. if a human can tell they are in a large room based on speech, say, their experience tells them what it will do at frequencies far lower than their voice. Ditto a small room. If we try to game the system by creating a separate path for the bass, I am guessing that a listener will feel that something is amiss - all the cues and sensations won't add up.

Not that I have noticed. Indeed bass frequency resonances can last more than each consonant in English language causing intelligibility problems with voices.

A boomy room remains a boomy room. Just get a sub and turn it up and try to listen to music. You will notice the boomy sub no matter what.

 

[sergeauckland]

Not that I have noticed. Indeed bass frequency resonances can last more than each consonant in English language causing intelligibility problems with voices.

A boomy room remains a boomy room. Just get a sub and turn it up and try to listen to music. You will notice the boomy sub no matter what.

Whilst I don't disagree in principle, I wonder just what sort of rooms people have if the bass resonances are sufficient to cause speech intelligibility problems. ALL the rooms I've had over the years have not given me any problems of that sort. It may have something to do with construction methods, as all my rooms have had solid plaster over brick walls and concrete floors, not drywall or suspended floors, but if anything, I would have thought that those rooms would have had more boom, not less, given that drywall and suspended floors are lossy.

So, are some of us just a lot more sensitive to room modes? The room I'm currently using gives me an in-room response that doesn't deviate more than +-3dB up to about 1kHz, where the response starts to drop gently downwards. The maximum peak is at 80Hz (floor to ceiling mode) but that's only about 3dB high, so I haven't done anything about it. My room is completely untreated and no DSP room correction, so am I just lucky? If so, then I've been lucky in all my houses over the years.

I do use DSP to equalise my 'speakers flat on-axis pseudo anechoically, but not for LF correction.

S.

 

[Theo]

Lots of comments about distortion induced by the recording/reproduction systems indicating that this a non-trivial question. Variability of opinions tends to show that hearing varies from one to another. Not a big surprise, is it?
Here is another phenomenon which should be taken into account: the distortion generated by the ear itself, especially IMD, which "can create additional harmonic content and add spatial depth when incorporated in music" as mentioned in the paper linked below.
Paper
We may each have our own distortion spectrum (varying with age). Combined with the loudspeaker generated HD-IMD, this may explain the tendency to like a little bit of "warmth" (like tube warmth): when the patterns are similar, the ear may 'like" it... Would this explain the diferent sensitivities we have to certain parameters and our tastes in audio gear and music? How do we measure it and take it into account? Listening tests for everybody?

 

[oivavoi]

FWIW: I'm among those who thinks that eq can be useful based on room response in lower frequencies. For me this is based on personal experience. When adding a sub to a setup, I have often experienced a "boominess" that goes away when I apply eq in the bass. I think it has to do with two things:

1) In the deep bass we don't hear any direct sound, basically we only hear the room. Intuitively, it therefore makes sense to me to apply eq based on the room.

2) Most venues where live music is heard are reasonably big, which make the problem with room modes much smaller. Most domestic rooms are small by comparison, so overhang in the bass can mask things which go on in higher frequencies.

Strangely, though, I don't perceive any boominess at all with the D&D 8Cs, even though the room I have at the moment is extremely small. I even haven't bothered to try out the EQ, because I like it so much as is, and I will move quite soon. But this might also have to do with the fact that it's a wooden house with thin wooden walls and floors. It might be that the deep bass simply leaves through the wooden room boundaries.

------

Let me also add some thoughts on my experience of playing grand pianos in different venues, including some cramped domestic living rooms (cool that there are so many people here with experience from live instruments btw!). Not many people put a concert piano in their living room - but they do exist. My clear experience is that some rooms are too small for a concert grand. The bass can then overpower the room, and the whole sonic result will become more muddy. In such small rooms, a smaller piano with less energy in the bass will be better. I also think that some active bass traps could help.

But I don't see any difference in principle between how instruments and speakers behave in small rooms. Speakers sound better in larger rooms, just like instruments do.

 

[Jakob1863]

<snip>

But I don't see any difference in principle between how instruments and speakers behave in small rooms. Speakers sound better in larger rooms, just like instruments do.

It surely depends on the instruments (classes of and specific realisation within) - assumed at least a minimum sized room - as some are better at projecting as others and so more made for smaller rooms.
And it depends what we are looking at, distribution of some instruments might be not so much different from a single loudspeaker reproducing the same content, but there is a profound difference if we examine the virtual/phantom sound source on the medium plane in the two channel case.

 

[sergeauckland]

Lots of comments about distortion induced by the recording/reproduction systems indicating that this a non-trivial question. Variability of opinions tends to show that hearing varies from one to another. Not a big surprise, is it?
Here is another phenomenon which should be taken into account: the distortion generated by the ear itself, especially IMD, which "can create additional harmonic content and add spatial depth when incorporated in music" as mentioned in the paper linked below.
Paper
We may each have our own distortion spectrum (varying with age). Combined with the loudspeaker generated HD-IMD, this may explain the tendency to like a little bit of "warmth" (like tube warmth): when the patterns are similar, the ear may 'like" it... Would this explain the different sensitivities we have to certain parameters and our tastes in audio gear and music? How do we measure it and take it into account? Listening tests for everybody?

I don't doubt that some additional distortion is 'nice', it gives the sound 'body', and thus accounts for why some people are happy to use valve amplifiers, especially of the SET variety, NOS DACs, horn loudspeakers, or indeed why some still prefer LP playback to digital.

However, if one is as anally retentive as I am, I really don't care what anything sounds like, as long as it measures correctly. If it measures correctly, then if I don''t enjoy it, that's MY fault, not that of the equipment.

S.

 

[oivavoi]

And it depends what we are looking at, distribution of some instruments might be not so much different from a single loudspeaker reproducing the same content, but there is a profound difference if we examine the virtual/phantom sound source on the medium plane in the two channel case.

Absolutely. Personally I struggle to become "convinced" by the illusion presented to my brain by loudspeakers, no matter how good they are. I just doesn't sound real to me, in an ultimate sense. I suspect that has a lot to do with the dispersion pattern, and the fact that the phantom images don't excite the reflections of the room.

 

[amirm]

Whilst I don't disagree in principle, I wonder just what sort of rooms people have if the bass resonances are sufficient to cause speech intelligibility problems. ALL the rooms I've had over the years have not given me any problems of that sort.

Well, for music people don't pay enough attention to words to be noticed. Try watching movies and any borderline dialog gets worse that way.

Regardless, this is one of those effect that you don't notice as much in the negative, than positive. That is, remove the problem in bass and you instantly realize how important it is. The sound becomes so much less restrained and open. That boominess rigning is masking a lot of low level detail due to huge energy in bass frequencies.

Once there, you notice it a lot more. This is why my show reports frequently mentions room being boomy.

 

[svart-hvitt]

Yes, I had already seen one Kii reviewer who went straight for the room correction - it's an almost universal mindset, particularly among the people who would be in the market for DSP-based speakers. B&O supply their own room correction system also, I believe - but the enlightened listener could at least turn it off

Just curious: Have you ever heard Kii, DD8c or BO90?

 

[Fitzcaraldo215]

I consider live performances that I experience(in that space) to be just that. Reproduced performances(in our space) as just what they are. Different things altogether. All the wishing and hoping and huffing and puffing will not bring them together unless individual psychoacoustic wishing takes over the difference.
The recording of the performance is a distorted impression of the original and the path to the consumer just adds more distortion, as does the listening experience.

I wonder why there is so much interest given to it. Lengthy opinion posts that don't go anywhere. Druthers surpassing reality.

Enjoy live performances and enjoy recordings, or not.

2ch or more, the recording is not 'real' and 'reproduction' in a random space is shaped by environment and expectations.

That's life.

.

Well, yes, of course live and recorded are different. But, misguided or doomed to failure in my quest though I might be, I continue to seek reproduction in my home that more closely approaches what I hear live. That is my expectation, my gold standard, though realistically, like all things, it will never be perfectly achieved. But, much as my sound gives me musical listening pleasure today, I am not just going to give up and be totally satisfied with or complacent about something that falls short.

I have been both surprised and delighted by the huge progress home audio reproduction has made in the the decades I have been engaged in it as a hobbyist and music lover. I do not share your apparent pessimism about the gap vs. live. From the get go in my teens, I never did see high fidelity reproduction as a plateau. I saw it as an ongoing quest to further improve sound to make it ever closer to the ideal of the sound live performance. The past 10 years have been a particularly exhilarating step forward for me personally with improvement toward the ideal far beyond my expectations. I am much less mindful of the reproduced vs. live gap routinely in listening today.

We have had both continuous, evolving improvement plus some major breakthroughs - stereo vs. mono, Mch vs. stereo, digital vs. analog, etc. Yes, we have also had many false starts, dead ends and overblown claims along the way. Though audio technology is mature and further improvement trying, difficult and largely incremental, it has come a long way, it is better than ever, and I see no reason it cannot go further still.

 

[Fitzcaraldo215]

But I don't see any difference in principle between how instruments and speakers behave in small rooms. Speakers sound better in larger rooms, just like instruments do.

I think implicit in your comment is the notion that the only important sounds we hear are the direct sounds from the instrument or speaker itself. In the concert hall, we actually hear inseparably direct + reflected sound, and most in the audience hear considerably more reflected energy than direct. This has been amply proven many, many times objectively.

Oversimplifying, large performance spaces have much, much longer sonic reflected path lengths than small rooms, introducing much more time delay or reverb in the perceived diffuse sound spectrum than small rooms. Reflections and distance from the stage also alter the frequency balance, generally attenuating the highs and adding more emphasis to the bass - so called "warmth". Different halls do this to a different degree, and some are traditionally considered acoustically "ideal" in terms of how they influence sound in the audience for orchestral music - the Concertgebouw, Symphony Hall Boston, the Musikvereinsaal, etc. Attempts by acousticians to reproduce the specific sound parameters of those halls in newly architected ones via measurement, etc. have been decidedly mixed. Nontheless, typical symphony or chamber venues have more in common than they do differences, owing to the large space and typical performance arrangement they are dealing with, though some are considered better than others.

Bottom lines:

-- it is not about speakers or instruments, it is about direct sound coupled inseparably to our ears with delayed, reflected sounds from the hall that makes a large concert venue sound different.
-- no way on earth a listening room or small venue can simulate the reflected sound field of a concert venue, even for chamber or solo music. The listening room audio path lengths are hopelessly too short with insufficient time delay of reflections and without the tonal balance contributed by reflections and attenuation in air at the greater distances in the large hall.
-- the reflected sound field in the hall is also spatially multidimensional in xyz space, and it is important to keep the spatial directions of the reflected sound field properly oriented in xyz space on playback for maximum faithfulness to the live sound.
-- stereo redirects all sound at the listener from the front only, a small fraction of even 360 degree xy space as heard in the hall and losing directional information of much of the perceived spatial sound field.
-- an excellent, viable compromise to the above is 5/7.1 discretely recorded Mch sound. While limited to only xy, not xyz, it can capture and direct the reflected sounds at the listener on playback while preserving much of the 360 degree spatial aspect of the sound in the hall via direct and phantom imaging.
-- possibly, Immersive 3D in xyz space is better still, but it has not yet been commercially viable for music recordings, unlike xy Mch which enjoys a persistent, though small, commercial niche in classical music.

 

[Wombat]

I think implicit in your comment is the notion that the only important sounds we hear are the direct sounds from the instrument or speaker itself. In the concert hall, we actually hear inseparably direct + reflected sound, and most in the audience hear considerably more reflected energy than direct. This has been amply proven many, many times objectively.

Oversimplifying, large performance spaces have much, much longer sonic reflected path lengths than small rooms, introducing much more time delay or reverb in the perceived diffuse sound spectrum than small rooms. Reflections and distance from the stage also alter the frequency balance, generally attenuating the highs and adding more emphasis to the bass - so called "warmth". Different halls do this to a different degree, and some are traditionally considered acoustically "ideal" in terms of how they influence sound in the audience for orchestral music - the Concertgebouw, Symphony Hall Boston, the Musikvereinsaal, etc. Attempts by acousticians to reproduce the specific sound parameters of those halls in newly architected ones via measurement, etc. have been decidedly mixed. Nontheless, typical symphony or chamber venues have more in common than they do differences, owing to the large space and typical performance arrangement they are dealing with, though some are considered better than others.

Bottom lines:

-- it is not about speakers or instruments, it is about direct sound coupled inseparably to our ears with delayed, reflected sounds from the hall that makes a large concert venue sound different.
-- no way on earth a listening room or small venue can simulate the reflected sound field of a concert venue, even for chamber or solo music. The listening room audio path lengths are hopelessly too short with insufficient time delay of reflections and without the tonal balance contributed by reflections and attenuation in air at the greater distances in the large hall.
-- the reflected sound field in the hall is also spatially multidimensional in xyz space, and it is important to keep the spatial directions of the reflected sound field properly oriented in xyz space on playback for maximum faithfulness to the live sound.
-- stereo redirects all sound at the listener from the front only, a small fraction of even 360 degree xy space as heard in the hall and losing directional information of much of the perceived spatial sound field.
-- an excellent, viable compromise to the above is 5/7.1 discretely recorded Mch sound. While limited to only xy, not xyz, it can capture and direct the reflected sounds at the listener on playback while preserving much of the 360 degree spatial aspect of the sound in the hall via direct and phantom imaging.
-- possibly, Immersive 3D in xyz space is better still, but it has not yet been commercially viable for music recordings, unlike xy Mch which enjoys a persistent, though small, commercial niche in classical music.

Also, the microphones dotted in and around the orchestra are not 'hearing' what audience individuals hear.

 

[RayDunzl]

When critically listening, I'm happier with my lower harmonically distorting less bouncing off the walls dipoles than with my higher harmonically distorting more bouncing off the walls LSR 308, irregardless of the source material.

When casually listening, they're interchangeable, and the JBL are my economical daily drivers now.

Both need similar correction applied in the bass region - a peaky hump at 35Hz, a broad hump around 100Hz, and cancellation around 45Hz. This, despite the JBL claimed flatness anechoically, and the whatever-curve the dipoles have.

Raw room measure, with settings on the speakers set for "less bass", but no DSP.

 

[Blumlein 88]

Wonder about this idea Room EQ is no good above the Schroeder frequency. If you have a highly flat speaker in an anechoic chamber ok.
But what about those that aren't?

I'm thinking of two speakers I've had the chance to measure with Tact gear, with Dirac, and with REW. I've done this in more than one room, and more than one spot in that room, and more than one listening position for both speakers.

I need to pull out those measures, but from memory above 300 hz all three measuring methods using 1/6th smoothing look nearly identical. Same overall trend for each speaker, and each speaker has different trends. Does this trend mesh with the anechoic results? I don't know, but you would think at least broadly it must. So a well chosen room curve for a target and 1/6th smoothing to adjust I would think perhaps you are getting the speaker close to how it might have a flatter anechoic result. Directional features are more complex, but at least mostly on axis seems a likely improvement.

Then it occurred to me that our own hearing does something like 1/4 and 1/5 th octave smoothing and wider at lower frequencies. Maybe that is part of how our ears ignore the room and hear thru it to the direct first arriving sound. It surely would only be part what our brain/ears do.

So maybe a good experiment would be to measure the little 305s a few places in a large and small room, and outside in the backyard. See if anything reliable shakes out. I would think maybe Harman has done this research. Maybe someone can point to it if they have. My conjecture is perhaps the right amount of smoothing varying with frequency (maybe ERB smoothing) and different windowing for different size rooms might let you look back to what the speaker is doing anechoicly. In which case if a speaker has consistent trends from flatness room EQ isn't a mistake. That perhaps rather than precise sub-hz response flattening what you really need is wider smoother adjustments leaving in the differences that come from the room itself.

 

[amirm]

Then it occurred to me that our own hearing does something like 1/4 and 1/5 th octave smoothing and wider at lower frequencies. Maybe that is part of how our ears ignore the room and hear thru it to the direct first arriving sound. It surely would only be part what our brain/ears do.

The frequency resolution of the ear shrinks proportional with frequency. From my article: https://audiosciencereview.com/forum/index.php?threads/perceptual-effects-of-room-reflections.13/

So the ideal filtering would vary from low to high frequencies. I use 1/12 or so just about transition frequencies (200 to 600 Hz) and then progressively make it smaller depending on what I am looking at. For just toal response I will use 1/6th.

 

[Blumlein 88]

The frequency resolution of the ear shrinks proportional with frequency. From my article: https://audiosciencereview.com/forum/index.php?threads/perceptual-effects-of-room-reflections.13/

So the ideal filtering would vary from low to high frequencies. I use 1/12 or so just about transition frequencies (200 to 600 Hz) and then progressively make it smaller depending on what I am looking at. For just toal response I will use 1/6th.

BTW, we were saying different things about width of filters at various frequencies. In octaves of width, the ear is filtered wider in the low end. In terms of width in hertz yes the filtering is narrower in low frequencies. I used octaves as smoothing is usually in fractional octaves. Fortunately REW has an ERB smoothing option.

 

[Cosmik]

Just curious: Have you ever heard Kii, DD8c or BO90?

No, although I have heard the B&O 50.

My experience of such speakers is mainly through the ones I have built, which go directly for neutral as much as I can make them. They produce a true step output.

Long before the speakers you mention, I made the decisions to go for sealed, three way, DSP, linear phase, time aligned, etc. so my assumption is that these commercial ones will sound very similar. I didn't do listening tests in order to decide on sealed vs. ported, DSP vs. passive, two-way vs. three way, etc. and I don't think the above manufacturers did either; they just took the obvious direct line to 'neutral'.

My speakers don't have the bass dispersion control, of course, but the boxes are wider than modern speakers so at least they go a bit lower before going omni-directional.

The upshot is that the whole process was straightforward with no mystery and no 'voicing' (as the D&D guy said about their speakers) except for what basically constitutes baffle step compensation derived from a standard calculated curve based on the baffle width, plus I have an adjustable bass roll-off.

So I don't ascribe anything mysterious to speakers any more, and when I read reviews of the speakers you mention I notice people saying things that reflect my experience. But there's always the possibility I will be appalled when I finally hear them!

 

[Wombat]

No, although I have heard the B&O 50.

My experience of such speakers is mainly through the ones I have built, which go directly for neutral as much as I can make them. They produce a true step output.

Long before the speakers you mention, I made the decisions to go for sealed, three way, DSP, linear phase, time aligned, etc. so my assumption is that these commercial ones will sound very similar. I didn't do listening tests in order to decide on sealed vs. ported, DSP vs. passive, two-way vs. three way, etc. and I don't think the above manufacturers did either; they just took the obvious direct line to 'neutral'.

My speakers don't have the bass dispersion control, of course, but the boxes are wider than modern speakers so at least they go a bit lower before going omni-directional.

The upshot is that the whole process was straightforward with no mystery and no 'voicing' (as the D&D guy said about their speakers) except for what basically constitutes baffle step compensation derived from a standard calculated curve based on the baffle width, plus I have an adjustable bass roll-off.

So I don't ascribe anything mysterious to speakers any more, and when I read reviews of the speakers you mention I notice people saying things that reflect my experience. But there's always the possibility I will be appalled when I finally hear them!

I seem to remember a representative/s of one or more of the three loudspeakers state that they used psychoacoustics in the design of their speakers.
Are there Standards for such algorithms or for a standard reference model that accommodates variation between individuals.

Application of psycho acoustics is a generally a tweak to fool us into believing the smaller boxes are punching above their weight. Could we call them lossy loudspeakers or lousy losspeakers. For all the kudos given to these items on this forum the opinions have been individually subjective - no technical depth beyond general comments from the mfrs.

??????

 

[svart-hvitt]

No, although I have heard the B&O 50.

My experience of such speakers is mainly through the ones I have built, which go directly for neutral as much as I can make them. They produce a true step output.

Long before the speakers you mention, I made the decisions to go for sealed, three way, DSP, linear phase, time aligned, etc. so my assumption is that these commercial ones will sound very similar. I didn't do listening tests in order to decide on sealed vs. ported, DSP vs. passive, two-way vs. three way, etc. and I don't think the above manufacturers did either; they just took the obvious direct line to 'neutral'.

My speakers don't have the bass dispersion control, of course, but the boxes are wider than modern speakers so at least they go a bit lower before going omni-directional.

The upshot is that the whole process was straightforward with no mystery and no 'voicing' (as the D&D guy said about their speakers) except for what basically constitutes baffle step compensation derived from a standard calculated curve based on the baffle width, plus I have an adjustable bass roll-off.

So I don't ascribe anything mysterious to speakers any more, and when I read reviews of the speakers you mention I notice people saying things that reflect my experience. But there's always the possibility I will be appalled when I finally hear them!

Interesting!

Do you have picture(s) of your creatures? Or maybe you’ve described the design and making process elsewhere?

 

[Cosmik]

I seem to remember a representative/s of one or more of the three loudspeakers state that they used psychoacoustics in the design of their speakers.
Are there Standards for such algorithms or for a standard reference model that accommodates variation between individuals.

Application of psycho acoustics is a generally a tweak to fool us into believing the smaller boxes are punching above their weight. Could we call them lossy loudspeakers or lousy losspeakers. For all the kudos given to these items on this forum the opinions have been individually subjective - no technical depth beyond general comments from the mfrs.

??????

These cardioid type speakers are designed to meet a specific goal (uniform dispersion at all frequencies), so they are not, IMO, fooling us in that regard: I think they are just meeting that goal better than other speakers.

The one area where psychoacoustics might come into operation is the bass limiting at very high SPLs, where the system may do things dynamically, and maybe there are specific tricks necessary to make it more transparent. Then yes, I would see that a smaller box is being pushed into an area where it is struggling - but by all accounts this is only at very high SPLs indeed. The Kii uses motion feedback, so its bass is probably counter-intuitively strong and clean anyway.