[John Casler]

With all the concern over the most miniscule amounts of "smearing and distortion" in their components and cabling, I wonder if anyone knows how much "distortion" is introduced by the listening room?

Distortion is "any" addition or subtraction of the original purity of signal.

I would guess it is in the neighborhood of at least 30-40%

Has anyone heard any numbers?

[angelo]

the distortion that occurs in equipments and speakers are based on electrical, magnetic, mechanical phenomenon while a listening room is basically a space of air where sound travels, to say "room distortion" would be very inaccurate when comparing to equipment distortion that can be measured by analyzers.

maybe ethan w. have some figures with regards to room effects and acoustical treatments

angelo

[zybar]

With all the concern over the most miniscule amounts of "smearing and distortion" in their components and cabling, I wonder if anyone knows how much "distortion" is introduced by the listening room?

Distortion is "any" addition or subtraction of the original purity of signal.

I would guess it is in the neighborhood of at least 30-40%

Has anyone heard any numbers?

John.

If you measure most rooms, you will see swings between 10-40 db's in frequency response.  Although this isn't technically distortion, it is absolutely impacting the sound you hear in a very negative fashion.

I agree that until people address the room (via proper placement, room treatments, and technology - Tact, DEQX, Rives, etc...), playing around with cables, power cords, etc... is just plain a waste of time and money.

Wish I had understood this a long time ago...

George

[John Casler]

the distortion that occurs in equipments and speakers are based on electrical, magnetic, mechanical phenomenon while a listening room is basically a space of air where sound travels, to say "room distortion" would be very inaccurate when comparing to equipment distortion that can be measured by analyzers.

maybe ethan w. have some figures with regards to room effects and acoustical treatments

angelo

Hi Angelo,

You are correct that the "sound" that is reflected and sent back into a room is not electrical, it is a mechanical distortion that likely could be measured in many ways.

I would think it could certainly have a Signal to Noise Ratio.

I would think that it would also have a type of "phase" distortion, since the frequency might be a pure tone, but the phase of the reflected sound would be a different story.

If I was in the "acoustics" biz (which obviously I'm not) I would be looking at finding measurments for these gross distortions and how the "treatments" I (if I were in that business) made or sold, addressed, them.

As I said, when I speak of distortions, I am talking about anything "subtracted from", "added to", or "adjustment of" the original signal, from the speaker to your ear/brain, that changes the "transfer function" of the performance as it was heard originally.

[John Casler]

John.

If you measure most rooms, you will see swings between 10-40 db's in frequency response.  Although this isn't technically distortion, it is absolutely impacting the sound you hear in a very negative fashion.

I agree that until people address the room (via proper placement, room treatments, and technology - Tact, DEQX, Rives, etc...), playing around with cables, power cords, etc... is just plain a waste of time and money.

Wish I had understood this a long time ago...

George

I think we think alike here.

I would think that (and I could be wrong) in a "reproduction" environment, any measurable signal beyond what is measured in "anechoic conditions" would be considered distortion, since it would be absolutley impossible for it to be anything else?

Yes?

The questions are; Just how much can affect the sound, How much it affects them,  and What are acceptable levels?

[8thnerve]

John, you are correct.  They are massive amounts of distortion caused by any enclosed space, that are measureable in the frequency and especially the phase domain.  Measuring these distortions however are quite hard as there are too many factors to test in an actual room.  Testing requires an anechoic room (or a very controlled and large freefield environment) with many tests of material types, shapes and sizes to understand how the basic individual elements within a room affect the phase and distortion of the signal, so that we can then start to add them together to see how they interact with each other, and what the end result is.  The problem is the large amount of testing and money that is required to do such a thing.

Fortunately, you can be a part of the history making process.  Just send a donation to the Eighth Nerve architectural acoustics reasearch and development department, and we'll give you the latest in room acoustic treatment designed to eliminate said distortion until we quantify all the phenomenon and adjust the products to reflect our discoveries.  

[Ethan Winer]

John,

> I wonder if anyone knows how much "distortion" is introduced by the listening room? <

As George explained, the word "distortion" is best reserved for true nonlinearity, where new frequency content is created, such as THD and IM distortion. Those can be expressed as a percentage of the original source. The room effects you're describing show up as simple frequency response errors, and also echoes.

> I would think that it would also have a type of "phase" distortion <

There too, the only damage done by phase shift is to the frequency response when the original and shifted versions are combined.

--Ethan

[Ethan Winer]

George,

> until people address the room ... playing around with cables, power cords, etc... is just plain a waste of time and money. <

No kidding. I recently had a customer tell me he was about to "upgrade" his system by buying $5,000 worth of speaker cables, but realized just in time he'd be better off getting room treatment. For a lot less than $5k I might add!

--Ethan

[8thnerve]

There too, the only damage done by phase shift is to the frequency response when the original and shifted versions are combined.

I disagree slightly with this; I would state that as "the damage done by phase shift is to the musical signal when the original and distorted versions are combined."  I do believe that the room causes nonlinearity that would classify accurately as distortion, not just frequency abberations.

[Ethan Winer]

Nathan,

> I do believe that the room causes nonlinearity that would classify accurately as distortion <

Nonlinearity always adds new content in the form of harmonics or other artifacts (such as aliasing), but how could a room do that?

--Ethan

[John Casler]

 John, you are correct.  They are massive amounts of distortion caused by any enclosed space, that are measureable in the frequency and especially the phase domain.  Measuring these distortions however are quite hard as there are too many factors to test in an actual room.  Testing requires an anechoic room (or a very controlled and large freefield environment) with many tests of material types, shapes and sizes to understand how the basic individual elements within a room affect the phase and distortion of the signal, so that we can then start to add them together to see how they interact with each other, and what the end result is. The problem is the large amount of testing and money that is required to do such a thing.

Fortunately, you can be a part of the history making process. Just send a donation to the Eighth Nerve architectural acoustics reasearch and development department, and we'll give you the latest in room acoustic treatment designed to eliminate said distortion until we quantify all the phenomenon and adjust the products to reflect our discoveries.
...

Hi Eighth,

Thanks for the "opportunity"    

And the input.  I know many accept some of the "room" sound as part of the system.  

While I know it is impossible to "do away with it totally", My main intent is to "manage" it to reduce it's contribution to the original recorded signal.

I like this Circle, since I think you and Ethan give a lot of info, which is sorely needed (what does sorely mean here?)

Anyhow, I think it is valuable to recognize that a venue "uses' the room to make the sound of the recording (or perfromance)  sound a certain way.  BUT....When we get into a playback room, using the room takes on a different perspective which is "destructive" to "reconstructing" the original.


I'll participate in your project by occasionally posting what I think are "stimulating" proposals, concepts, and even stupid ideas.

[8thnerve]

Nathan,

> I do believe that the room causes nonlinearity that would classify accurately as distortion <

Nonlinearity always adds new content in the form of harmonics or other artifacts (such as aliasing), but how could a room do that?

--Ethan

Well, here I am on sticky ground.  I hate to say it, but I can't get into too much detail, as I am pursuing patents on my new products which are designed to correct for this.  I have said for years however that corners are the most destructive element within a room, and it is obvious to everyone that has used my products that they are always intended to be placed in the corners, so the corner being my focus is obvious.

Based on the currently accepted acoustical physics formulas and theories, there is absolutely no reason why my products should work at all, much less to the degree that they do.  Add to that the fact that any of our customers would agree that they certainly do work, as evidenced by having only 2 returns in over 3 years, and it is clear that there are some major things that are not understood about architectural acoustics.

Sorry to be vague, but I guess what I am saying is what I have been saying all along, it's all about the corners!  How else can you explain the complete elimination of echo with 4 Seams and 4 Corners across the ceiling/wall boundary?  At any rate, once the new products are out, when launching the new website, I will put a new section of technical documents that will be as explicit as I can be about this phenomenon.

[8thnerve]

Anyhow, I think it is valuable to recognize that a venue "uses' the room to make the sound of the recording (or perfromance) sound a certain way. BUT....When we get into a playback room, using the room takes on a different perspective which is "destructive" to "reconstructing" the original.
 

Yes, but it is generally more complicated than that.  The actual recording is only one phase of the recording process.  The mixing which is one of the most critical phases, is never done in an anechoic chamber, therefore, trying to turn a listening room into one with little to no reflection will result in you not hearing what the artist, mixer, and producer wanted you to hear.  Most good studios are not nearly as dead as most people think.  They mix and determine the final sound in a room, so they are already "adding" to the original signal, by determining this in a room in the first place.  Add to that the fact that the acid test is taking the CD out to someones car (I'm not kidding, every major studio engineer does this) and then possibly adjusting the mix to compensate for that environment, and you are dealing with a complete change of this precious "original signal."

So where does that leave us then, if there is no chance that we can hear the original?  Well, we have to do our best to replicate the sound that was heard in the studio.  By eliminating the sound of the corners, we eliminate the sound of the room.  Flat wall reflection adds to the total energy of the output, but does little to define the room's sonic signature.  This leaves us with an energetic environment that is free from imparting most of it's own sonic character onto the reproduction.  Energy, extension, and the ambient cues that the mixer allows us to hear (or unintentionally left ) give us the best representation we can hope for in a real world scenario.  

If measurements are what convince you, realize that by adding absorptive material to your room, you reduce some of the peaks in the upper portion of the spectrum and less in the lower portion.  You ALSO lower the troughs as well, as you are simply reducing all acoustic energy; essentially turning down the volume on echo and distortion, which happens to be more effective at higher frequencies where echo is most conspicuous.  In contrast, by treating the corners the way that we do, we eliminate a good deal of distortion in the first place, which not only reduces the peaks EVENLY across the spectrum, but also increases the troughs!  Why?  Because the distortion acts as a comb filter on the original signal causing peaks and troughs; by reducing this distortion, we move back towards the original signal which contains neither.

That is what our products are designed to do, and I believe it is the only way to accurately treat a room.  Don't you find that your traps are especially effective when placed in the corners Ethan?

[Ulas]

With all the concern over the most miniscule amounts of "smearing and distortion" in their components and cabling, I wonder if anyone knows how much "distortion" is introduced by the listening room?

That’s an interesting premise. Paraphrased, it means the sound coming from the speakers is pure and true to the source but what we hear is colored and distorted by the room. The goal then is to nullify the effects of the room.

Let’s apply the same reasoning to musical instruments; the guitar, for example. The guitar sound is created by the vibrating strings which is amplified, colored and distorted by the body of the instrument. I think the first thing an audiophile/guitarist would do is stuff the guitar box with acoustical foam to cancel the nasty reflections inside. Then isolate the bridge from the soundboard with sorbothane or other constrained layer damping material. Ideally, you would eliminate the guitar body altogether and use a highly damped, non-resonant material to support the strings.

Pretty silly, huh? The guitar is the guitar. Every one sounds different and that’s the way it should be. It’s pointless to try to change an instrument to sound like something it isn’t. That’s not to say that if a guitar has poor intonation or buzzing strings it shouldn’t be fixed. The same with the room: It is what it is and needn’t be “fixed” unless it is truly broken. My goal is to create the sound of the musicians performing in my room as it is. The last thing I want to make my room sound dull and dead like a recording studio.

[John Casler]

That’s an interesting premise. Paraphrased, it means the sound coming from the speakers is pure and true to the source but what we hear is colored and distorted by the room. The goal then is to nullify the effects of the room.

Let’s apply the same reasoning to musical instruments; the guitar, for example. The guitar sound is created by the vibrating strings which is amplified, colored and distorted by the body of the instrument. I think the first thing an audiophile/guitarist would do is stuff the guitar box with acoustical foam to cancel the nasty reflections inside. Then isolate the bridge from the soundboard with sorbothane or other constrained layer damping material. Ideally, you would eliminate the guitar body altogether and use a highly damped, non-resonant material to support the strings.

Pretty silly, huh? The guitar is the guitar. Every one sounds different and that’s the way it should be. It’s pointless to try to change an instrument to sound like something it isn’t. That’s not to say that if a guitar has poor intonation or buzzing strings it shouldn’t be fixed. The same with the room: It is what it is and needn’t be “fixed” unless it is truly broken. My goal is to create the sound of the musicians performing in my room as it is. The last thing I want to make my room sound dull and dead like a recording studio....

Ulas,

Talk about "silly".

I said nothing about subtracting the natural sounds of a guitar.

I said nothing about even subtracting the sound of the original venue.

If you think your room will "contribute" to the original recording then go for it.

[csero]

Ulas,

If you think your room will "contribute" to the original recording then go for it.

Yes it does. What do you think why recording engineers put the mics in front of the musicans or above the conductor's head, not 10th row in the audience?

[John Casler]

Ulas,

If you think your room will "contribute" to the original recording then go for it.

Yes it does. What do you think why recording engineers put the mics in front of the musicans or above the conductor's head, not 10th row in the audience?

Hi Frank,

Are you saying you feel the "reflected sound" from a 15 x 17 x 9 room will sound virtually the same as a 100 x 100 x 60 venue even when "overlaying" it?

[8thnerve]

That’s an interesting premise. Paraphrased, it means the sound coming from the speakers is pure and true to the source but what we hear is colored and distorted by the room. The goal then is to nullify the effects of the room.

Ulas, I don't think that is what John meant.  I read that to say that we as audiophiles spend a great deal of time and money to reduce distortion throughout the electrical components of our system, but very little time spent trying to reduce distortion caused by the room and its effect on the sound.  And I agree with John that the amount of room distortion is FAR greater than the distortion from our well made and very well-engineered electronics.

I also agree with you Ulas that mass absorption is the wrong way to go to correct that distortion, and I have cited several reasons for my case.  I think it is just as important to accurately fix room distortion as it is to realize that it is an issue in the first place.  Either way, the first step is realizing that acoustic treatment is a crucial part of any system where accuracy, realism and musicality are goals.

[csero]

Hi Frank,

Are you saying you feel the "reflected sound" from a 15 x 17 x 9 room will sound virtually the same as a 100 x 100 x 60 venue even when "overlaying" it?

No, (this is one of the big problems of stereo), but without it it will be even worse ( for 2 channel playback) .

[nathanm]

If the microphone(s) record a musician in a live, reflective room and you wish to hear what that microphone heard then your playback room should be far less live and reflective otherwise you're getting TWO layers of reverb instead of one.  That is not to say that there is a right way or a wrong way to enjoy music IMO, but the fact remains that whatever word you use to describe it, be it distortion or reverb or whatever, the playback room's acoustics will be adding to the sound the less absorptive it is.  Objectively speaking this is a deviation from the source and less high fidelity.  If you record a guitarist in an anechoic chamber and play it back in a normal-sounding room it might sound more natural than it would in the chamber because we are so used to hearing reflected sound everyday; however it would not be faithful to the source.

My guess is that if people prefer listening in a live room then their choice of recordings perhaps feature very dry mixes.  In absorptive rooms dry recordings might sound subjectively dull and boring without the reverb. It's just basically a dry\wet balance you're dealing with and what the listener prefers.  An overly dead room might not satisfy because the particular recording might not have the level of reverb\presence qualities the listener enjoys.  I think this is due to both engineering practices and the relative insensitivity and lack or reach that microphones have in comparision to the human hearing mechanism.  You have to put most mics closer to the source than you have to put your head in order to record the same apparent level.  But then again I haven't had experience with cool stuff like PZMs and the like so I am a little disappointed with the unreality of microphones in general.