[Ethan Winer]

Nathan,

> Most good studios are not nearly as dead as most people think. <

Probably, but it's important to distinguish between the "live" room where the actual recording takes place, and the control room where the mixing decisions are made later.

> Flat wall reflection adds to the total energy of the output, but does little to define the room's sonic signature. <

Except when a flat wall gives comb filtering. But you're implication is correct because comb filtering sounds the same from every flat wall assuming the same wall material. What changes the "sound" of the filtering is the distance from the wall and the angle of incidence.

> Don't you find that your traps are especially effective when placed in the corners Ethan? <

Of course, and you can see the difference in absorption with the exact same panel mounted both ways in the Absorption graph on our web site.

--Ethan

[John Casler]

 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.    

Hi Eighth,

I certainly agree that the results and recording chain are different and this of course means it is impossible to ever "get it right"

Although some engineers do rely heavily on "headphones" which "are" anechoic chambers.

Most of my concern stems from minimally miked "live venue" recordings and even they are sometimes "tampered" with to a large extent.

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."
 

Thus is the quandry.  However in this consideration we have a wide range of "engineering".

You have "minimally miked" live perfromances, you have multiple mike live perfromances, you have "studio" perfomances and probably many others.

You also have the same mulitple types of engineering and sonic manipulation, from minimalist to "total recreations" complete with studio echo/reverb and all.  (I really dislike that stuff)

Now the studio and "created" types of recording are generally the most "engineered" the "live" are still rather pure (let's hope).

That is, even though an engineer uses a specific room to "master" the recording, he does not "add" that room's sonic into the recording he just uses it (as a model) to make "trims" and adjustments of gain and balance.

In this case, one might best benefit from using a similar set up "if" one wanted to hear what a control room sounded like at mastering.

This might be the "best there is".  I have a tendency to doubt it.


 

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.  

I mostly agree with that.  I have many times ask or tried to list, the types and placement of room treatment to address the "hot spots" in order of importance and then continue on to approach the minimum room distortion.

 

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.
 

Actually measurments "don't" always convince me, since they really aren't what you hear.

I have been told that absorbative room treatment will reduce "HF" energy.  While this may be true to a measuring device, it is certainly not true to the original signal and doing so causes a improved perception of HF sonics and clairity.

Many times I have used the example of bright car lights coming at you at night and same lights during the day.  The direct energy from the lights is exactly the same, but all the ambient light during the day, "attenuates" the perception of the amount of brightness during the daytime.

 

That is what our products are designed to do, and I believe it is the only way to accurately treat a room.  

I look forward to your "new" product.

[csero]

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.  Ob ...

Not only that, but hearing is also sensitive to the direction of the room reverbs.
If you put a stereo mic pair in a live room at normal listening distance, it will pick up the reflected sound from all directions and lump them together without the directional info.
Played this back on a stereo setup even in a dead room, will not have the right balance of direct/reflected sound, because too much reflected sound ( early reflections and reverberation together ) coming from the front, and nothing from the back. This result in the bathroom sound - too much echo, even when the summed direct/reflected ratio is correct.

So for stereo, you are better off if you don't record too much "room sound", but try to add it with the actual listening room. Like LEDE, Dead End not to add any more at the speaker side, and Live End to add the missing behind you. They usually does not match, but sometimes they are not that far, and then you get the famous, "like the musicans standing in my room" sound. This is working for some records, not for the others, and definitely not portable ( which is IMHO the base of most of the gear fights in audiophilia ).

Room treatments are not (just) for correcting frequency anomalies, but rather create an acoustic environment, which is with it's own early reflection/reverb pattern is a livable space for the music you are going to listen to. For somebody it means big, live rooms, for others small, heavily treated ones.

[John Casler]

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) .

Hi Frank and I agree that there are a lot of problems with "stereo".

I will say however that I have done a considerable amount of critical listening in the extreme nearfeild and under (near) anechoic conditions, and have to say that the realism and ability to hear into a recording venue (in well done live recordings) is breath taking

When hearing the same recording in an untreated room the destructive effect is drastically different.

Since most have not had this opportunity, I felt the concept interesting.

The reason I posted this thread is to stimulate discussion of such from audiophiles and acousticians (of which we have some of the best).

While the variety of the recording processes is very wide, the only recordings that seem to suffer are the highly engineered ones, and even then, they don't always "sound bad" they just sound engineered.

Kinda like an electric keyboard against a live piano.  Both "can" sound good, if done right, but only one can sound "real".

[Ethan Winer]

Ulas,

> The guitar sound is created by the vibrating strings which is amplified, colored and distorted by the body of the instrument. <

Again, I wouldn't use the word distortion unless the strings are too low or the body is cracked and buzzing. But you are correct that body resonances define all acoustic instruments. And this defines the difference between an acoustic guitar and an electric guitar too! I play the cello, and own a pretty good one, so I know well what you're talking about.

However, this is very different from the sound of a room. You need the resonances in an acoustic instrument to get a unique and desirable sound from it. But resonances in a room can only be detrimental. This is not to say you want to make a listening room dead, because that's no good either. And with rooms I further divide the spectrum into bass and "not bass" because resonances have different effects (though both are a problem).

It seems to me the ideal listening room will not have severely pronounced resonances at any frequency. Especially below about 300 Hz, resonances only make a muddy mess of bass instruments. And resonances at midrange frequencies will cause some musical notes to sound louder and ring out for longer than others. So now we're down to simple comb filtering, which in "subdued amounts" is probably the most natural sound even though it causes a skewed response. But we're used to hearing it all the time. And the peaks from comb filtering are probably less damaging than peaks due to resonance because the latter also creates sustain.

--Ethan

[csero]

Hi Frank and I agree that there are a lot of problems with "stereo".

I will say however that I have done a considerable amount of critical listening in the extreme nearfeild and under (near) anechoic conditions, and have to say that the realism and ability to hear into a recording venue (in well done live recordings) is breath taking

When hearing the same recording in an untreated room the destructive effect is drastically different.

Since most have not had this opportunity, I felt the concept  ...

I know what you are talking about, I had extremely directional speakers in heavily treated room. Haven't you ever felt that you can hear every small detail of the record, but you are just not part of it? I definitely would not use the world "realism" for that.

[woodsyi]

My room definitely sounds better after room treatment than before.  With my room, acoustic double bass was a bear to get right.  For my test record, Collosus by Sonny Rollins, I had to attenuate bass to account for the resonant peak.  This also meant I had to reduce the mid/treble.  After room treatment with various Real Traps, no more unwanted resonant boost.  I can hear the individual strings with just the right decay.  I even undamped my woofers to get them more lively.  Strange as it may sound, I also hear more clear details on top.  It may have to do with early reflection panels but I think it also has to do with the fact that I can play the mid/treable at a louder volume and still be in balance with bass notes.  If putting basstraps and early reflection absorbers are killing my stereo sound, I would die a thousand death!

[John Casler]

Not only that, but hearing is also sensitive to the direction of the room reverbs.
If you put a stereo mic pair in a live room at normal listening distance, it will pick up the reflected sound from all directions and lump them together without the directional info.
Played this back on a stereo setup even in a dead room, will not have the right balance of direct/reflected sound, because too much reflected sound ( early reflections and reverberation together ) coming from the front, and nothing from the ba ...

Frank,

ALL Excellent points, and I think right on the mark.

I would say though that, I have found in a very non-reflective room, that I "DO" get "some" of the perception of rear reflections, even though none are there.

My current room has (don't laugh ) six large blankets hanging from the ceiling. Two to each side and two to the rear.  These are down to well below ear level and only 3 feet away from each ear and the back of my head.

I don't know if the brain is "creating" the sonic impression, or if specific phase specific info from the recordings causes it, but without "interference" from side and rear diffusion, the effect is very realistic.

 

 I know what you are talking about, I had extremely directional speakers in heavily treated room. Haven't you ever felt that you can hear every small detail of the record, but you are just not part of it? I definitely would not use the world "realism" for that....

Hmmmm... No, the reality seems pretty good to me

I think the thing that most people miss is the extremely subtle and delicately structured sonic matrix that conveys the space in the actual room.  I mean this is "SUBTLE" and when there is a "competing" matrix overlaying it that is "more immediate", you lose touch with it.

Some can find part of it in a "very large" treated room in the nearfeild, but once you tap into it, it is something to reproduce as often as possible.

[John Casler]

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...

Hi Eighth,

You are correct about my intentions.

What I hear you saying is that you feel there are some "benign" room sonics????

This is an interesting concept and should deserve additional thought and discusion (as well as research and listening)

My point would be to acheive a reduction/elimination of most room interaction that affects the ear/brain reconstruction.  

Just like a small amount of light in a movie theater won't destroy the "projected" picture, it is a gradient reduction of any ambient light that is not directly from the projector, that makes the picture better.

I think that ultimatlely we may have a combo solution of DSP and Room Treatment.

It would also be valuable to be able to easily "adjust" the room interaction (how about a new product Ethan/Eighth)

That is, I see primarily at least TWO possibilities:

1) Very limited Interaction (bordering on anechoic) to allow for fine live recordings to project their spatial sonic matrix

2) Recording Engineering Room type Interaction to allow us to hear what the engineer intended

3) Other, which could be just about anything, including Techno/Computer Generated Sonics and specified spatial ambiences.

[BrunoB]

Sound reflection on room walls alters  frequency response but also decreases intelligibility, micro and macro dynamics. I don't know however, if these effects can be considered as distortions or measured as THD.

For playing movies, I found it beneficial to have a room as dead as possible. Dialogs are easier to understand and sound effects have more impact.

For playing music, the effect of the room is like adding a reverberation which can enhance some dry recordings. However, room enhancement might  not be easy to adapt individually to each  particular music/recording. For instance, for music recorded in a good large concert hall, I don't think that the added sound of room can enhance the playback of the recording. In my experience, with less room interaction (I have a near anechoic sound system), one can hear more of the concert hall reverberations.



Bruno

[8thnerve]

What I hear you saying is that you feel there are some "benign" room sonics????

Let's put this in terms of degree rather than benign versus harmful.  Let's say we have two things causing distortion, one at a one to one ratio, and one that is amplified by a certain amount, whether 1 or 6 db.  Which would be the most important type to eliminate or at least abate?  The amplified one of course.  Now look around your room and see if you can identify any shapes that would qualify an as acoustic amplifier.  Think about pro audio tweeters when doing this exercise.

Do you see what I am getting at?

[John Casler]

Let's put this in terms of degree rather than benign versus harmful.  Let's say we have two things causing distortion, one at a one to one ratio, and one that is amplified by a certain amount, whether 1 or 6 db.  Which would be the most important type to eliminate or at least abate?  The amplified one of course.  Now look around your room and see if you can identify any shapes that would qualify an as acoustic amplifier. Think about pro audio tweeters when doing this exercise.

Do you see what I am getting at?...

Oh Yes, I see what your getting at and have seen it for years.  Ever since I accidently stood in the corner to listen and realized the sonic interaction is produces.

[8thnerve]

Of course, and you can see the difference in absorption with the exact same panel mounted both ways in the Absorption graph on our web site.

I focus on the combined effect in a room rather than a product's individual absorption coefficients.  If you put four of your traps along the middle of each of four walls, and measure for the room's frequency response; and then put those same four traps in each of the four corners and measure again, you should see a much flatter frequency response from the latter configuration.

[Ethan Winer]

Nathan,

> then put those same four traps in each of the four corners and measure again <

Of course. Corners rule!

--Ethan