Spend less on speakers, more on acoustic treatment?

[tonmeister]

Hello all,

Is it fair to say that correct acoustic treatment is vastly underrated by most people? I'm working on my dedicated home theater room, and recently went on a "parade of homes" tour and was looking for theater ideas.

The thaters I saw were nice, and professionally designed, but the sound was just OK. The speakers used were theoretically very good.

However, I couldn't see any evident acoustic treatment. It could be that it was fantastically well hidden, but I don't think so.

It got me thinking about my own design and thinking about whether I should stop obsessing about speakers and start obsessing about AT.

Put another way, given a limited budget, might I be able to achieve pretty darned good results by focusing my efforts on A.T.? Granted, the speakers are only as good as they are good (A.T. won't improve them) but I'm guessing that in many, many cases what people actually have running at home (and what I saw in those theaters) is great equipment wasted in a bad space...

thoughts?

You got the title backwards. It should read: Spend MORE on speakers, and LESS on Acoustical Treatment"

Turning bad loudspeaker sound into HEAT [through absorption] is passe, a waste of energy, and environmentally irresponsible in 2010. Instead buy a good speaker so you need less treatment. Carpet, furniture and bookshelves (make sure a copy of Floyd Toole's "Sound Reproduction in on it after you read it] will take care of the rest.

 

[JerryLove]

Really? Ok, now repeat the test, without the speaker (acoustic source) and tell me what you hear and measure. Remember, the room itself will be otherwise completely unchanged. Tell me what "problem" with the room you find.

Done. Sound reproduction was reduced about 100%.

Your turn. Take a great pair of speakers and place them in vacuum and tell me what you hear and measure. Remember: the speakers themselves are unchanged (unless you decompressed them too fast and they blew).

So, if I understand where you are going: you've proven that speakers are 100% of the sound, and I've proven that rooms are 100% of the sound.

That or I've proven that your test is useless and has no real bearing to the question at hand.

OK. Now I'll take a pair of Bose bookshelves and put them in a well built home theater room. You take whatever your favorite speakers are and put them in the shower at the local gym. Let's see who's sound better cranked up.

I can tell you in advance that everyone will prefer mine, despite the lesser speakers.

The truth is, and the OP assumed this, both matter. The question is which, if either, is currently over-valued in the exchange.

There's no simple answer... except to recognize how many people fail to realize that the room is involved at all, or correctable at all, and therefore place zero value on room accoustics. Clearly the value is >0% (remember our vacuum experiment), and therefore many people undervalue room treatments.

 

[JerryLove]

Turning bad loudspeaker sound into HEAT [through absorption] is passe, a waste of energy, and environmentally irresponsible in 2010. Instead buy a good speaker so you need less treatment. Carpet, furniture and bookshelves (make sure a copy of Floyd Toole's "Sound Reproduction in on it after you read it] will take care of the rest.

I assume you are in violent opposition to the THX standards then?

 

[AJinFLA]

Done. Sound reproduction was reduced about 100%.

Hi Jerry,
I guess that joke sailed a bit over your head . That's ok.
Out of curiosity, does your room have acoustic problems? Is it "treated"?
Does it have problems unrelated those B&W's I saw pictured once, that you had to fix?
My weekend work schedule might be about to end after this week. Would you like to put your acoustics beliefs to test vs mine, firsthand, in a couple weeks?
Lemme know.

cheers,

AJ

 

[JerryLove]

Hi Jerry,
I guess that joke sailed a bit over your head . That's ok.

Perhaps it just wasn't funny.

Out of curiosity, does your room have acoustic problems? Is it "treated"?

All rooms have acoustic problems. The only question is severity.

There are no deliberate treatments in either of my listening rooms aside from speaker placement.

Does it have problems unrelated those B&W's I saw pictured once, that you had to fix?

Those speakers are not in use.

My weekend work schedule might be about to end after this week. Would you like to put your acoustics beliefs to test vs mine, firsthand, in a couple weeks?

If you like, though I've already proven it with my thought experiment, and with real-world examples everyone here is familiar with. But very well: we'll take your favorite speakers into an all-concrete room (perhaps an indoor pool area, or a bathroom with hard ceiling) and see if room interactions make any difference.

Perhaps afterwards we can walk outside and you can prove how the sound is completely identical there as in the tile room.

To say a room doesn't effect the sound waves in it is, simply put, insane.

 

[tonmeister]

I assume you are in violent opposition to the THX standards then?

I don't have a copy of them, so I will reserve judgment.

The new CEDIA recommendations for home theater acoustics make sense to me. One of the things they don't recommend is THX dipole surrounds, which make no sense as surround channels, and most of the commercial versions have terrible performance compared to a well-designed bi-pole or regular forward facing direct radiator.

 

[WmAx]

Jerry, I just got back in the house. I took all of my acoustical treatments and burned them out back in a bonfire since they were not contributing anything substantial. I guess I should have asked if you wanted them first .. sorry about that. Acoustically ideal rooms are pointless, man.

Now back to reality....

Ideal sound reproduction will always entail ideal acoustics. If someone truly wants the maximum level of performance, I can't see a way around acoustical treatments(to be defined as devices that manipulate the acoustic properties of a room to (a) targeted characteristic(s)). One can have better SQ in a typical room using speakers with certain properties. But maximum potential requires specific effort(s). And one need not use devices at 1st reflection points to remove what can be useful acoustic energy for SQ with the right speakers - acoustical treatments can be used in all sorts of ways. I use a non-traditional method of treatment as you may remember. Since my speakers benefit greatly from the 1st reflections, I do not treat these on the side or rear for 1st reflections; just ideal spacing from the walls. My treatments are elsewhere, to simply absorb random excessive echo/reverb and to greatly decrease crosstalk from L to R and vice versa (as you remember the unusual center panel system protruding from front wall penetrating deep into the room). Also, they are very broadband traps to reduce midbass and some LF resonance from the room. One can use treatments to benefit even a speaker with perfect off axis characteristics across the entire audible band even though this is not the typical method. (Most room treatment regiments use outdated LEDE and/or heavy removal of 1st reflections regardless of speaker polar radiation characteristics).

-Chris

 

[Alex2507]

You got the title backwards. It should read: Spend MORE on speakers, and LESS on Acoustical Treatment"

How much less?
How big is the Harman test room and how much was spent there?

One of the things they don't recommend is THX dipole surrounds ...

So now we have CEDIA and THX in direct opposition on what we should be doing?
I'm going to decare myself my own final authority on everything since I always agree with me.

Jerry, I just got back in the house. I took all of my acoustical treatments and burned them out back in a bonfire ...

Now that's funny ...

 

[AJinFLA]

All rooms have acoustic problems. The only question is severity.

There are no deliberate treatments in either of my listening rooms aside from speaker placement.

So if I understand you correctly, your room, which is one of "all rooms", has acoustics problems....that you solved by positioning the speakers...and required no "treatment"?
So exactly how does that differ from my and Sean's et al, position?

What room "problem" did you solve (via positioning), that was directly attributed to the room (all of which have problems)???

Those speakers are not in use.

Which ones are? Do any of the speakers used previously reveal the problems that must exist in the room?

If you like

I would hate to invite myself over if you don't like. This is going to be in your home, I'm the guest remember? Is your interest in having alien acoustic sources and beliefs in your room causing you to waver?

The room is rarely, if ever the problem.

though I've already proven it with my thought experiment, and with real-world examples everyone here is familiar with. But very well: we'll take your favorite speakers into an all-concrete room (perhaps an indoor pool area, or a bathroom with hard ceiling) and see if room interactions make any difference.
Perhaps afterwards we can walk outside and you can prove how the sound is completely identical there as in the tile room.

So, in your reality and "thought experiments", your (untreated) living room is the (real world) rarity and an "all-concrete room (perhaps an indoor pool area, or a bathroom with hard ceiling)" would be the norm for a listening room?

To say a room doesn't effect the sound waves in it is, simply put, insane.

Could you please use the forum "Quote" function and quote exactly who said that? TIA.

cheers,

AJ

 

[Seth=L]

I believe arguing with AJinFLA is akin to arguing with a concrete wall. This makes sense, he doesn't want his concrete surface to be treated.

 

[rmk]

Jerry, I just got back in the house. I took all of my acoustical treatments and burned them out back in a bonfire since they were not contributing anything substantial. I guess I should have asked if you wanted them first .. sorry about that. Acoustically ideal rooms are pointless, man.

Now back to reality....

Ideal sound reproduction will always entail ideal acoustics. If someone truly wants the maximum level of performance, I can't see a way around acoustical treatments(to be defined as devices that manipulate the acoustic properties of a room to (a) targeted characteristic(s)). One can have better SQ in a typical room using speakers with certain properties. But maximum potential requires specific effort(s). And one need not use devices at 1st reflection points to remove what can be useful acoustic energy for SQ with the right speakers - acoustical treatments can be used in all sorts of ways. I use a non-traditional method of treatment as you may remember. Since my speakers benefit greatly from the 1st reflections, I do not treat these on the side or rear for 1st reflections; just ideal spacing from the walls. My treatments are elsewhere, to simply absorb random excessive echo/reverb and to greatly decrease crosstalk from L to R and vice versa (as you remember the unusual center panel system protruding from front wall penetrating deep into the room). Also, they are very broadband traps to reduce midbass and some LF resonance from the room. One can use treatments to benefit even a speaker with perfect off axis characteristics across the entire audible band even though this is not the typical method. (Most room treatment regiments use outdated LEDE and/or heavy removal of 1st reflections regardless of speaker polar radiation characteristics).

-Chris

Excellent points Chris. I was told essentially the same thing by Keith Yates and he gets $250/hr for his thoughts.

 

[AJinFLA]

This makes sense, he doesn't want his concrete surface to be treated.

That is easily falsified, as when I had actual bare concrete surfaces (and similar cinder block) to contend with acoustically (back in '04). I did partially "treat" a single surface with a diffusive material (behind the dipole). The rest was just plain 'ol, wood, rugs, furnishings, etc, etc.
No loss of spaciousness, spatial realism or clarity (and unnecessary conversion to heat), from having insufficient reflections.

cheers,

AJ

 

[AJinFLA]

Excellent points Chris. I was told essentially the same thing by Keith Yates and he gets $250/hr for his thoughts.

Do you have any links to his AES papers or texts?
TIA

 

[WmAx]

Excellent points Chris. I was told essentially the same thing by Keith Yates and he gets $250/hr for his thoughts.

I am not familiar with Yates' most recent practices, but I do know that it used to be he recommended the same incorrect treatment suggestions as most room treatment 'experts'; that is, to reduce early reflections as a normal practice. This is counterproductive for modern high performance speakers that exhibit a very similar response off axis as compared to on axis, assuming correct spacing/placement, of course. Result would be a reduced realism of timbre and reduction in soundstage/spatial realism. Has he changed his stance on this?

-Chris

 

[haulin79]

To the OP,
It has nothing to do with the amount of money you spend on room acoustics. It all depends on how bad or good your room acousitcs currently are.

Some rooms have naturally good acoustics, so they don't need much improvement. For example, tapestries on the side walls, diffuse bookshelf in the rear.

We can put it into quantifiable terms:
A typical inexpensive speaker has a frequency response of, let's say, +/-3dB. Now, put those speakers in a room with professionally designed acoustics, the frequency response might now be +/-12 dB.

But let's say you put a "perfect" pair of speakers in an average room...the frequency response can now deteriorate to +/-30+ dB!

I'm a car guy, so here's a car analogy, lets say the room is analogous to the tires: The best car (speakers) in the world is useless with flat tires (poor room acoustics). At the same time, the best tires in the world won't make me want to drive a Yugo.

 

[WmAx]

Some rooms have naturally good acoustics, so they don't need much improvement. For example, tapestries on the side walls, diffuse bookshelf in the rear.

Just a FYI: If you mean to effect the 1st reflection points, a tapestry is not going to have an even broadband effect, nor will it be a good idea in the first place to try to absorb/diffuse the side reflections if the speaker has a near identical amplitude/frequency response far off axis as compared to on axis.

 

[rmk]

I am not familiar with Yates' most recent practices, but I do know that it used to be he recommended the same incorrect treatment suggestions as most room treatment 'experts'; that is, to reduce early reflections as a normal practice. This is counterproductive for modern high performance speakers that exhibit a very similar response off axis as compared to on axis, assuming correct spacing/placement, of course. Result would be a reduced realism of timbre and reduction in soundstage/spatial realism. Has he changed his stance on this?

-Chris

Like you, Yates has a very high opinion of himself. The difference is that he has designed and built several hundred Theaters and music rooms around the world. He also has the academic and real world credentials necessary to get those kinds of jobs. In other words, he walks the walk.

I do not know if he has changed his opinion on treating first reflection points but he downplayed their significance in my room and stated that he felt that was a conventional wisdom that is also a common error in treating some rooms.

 

[JerryLove]

So if I understand you correctly, your room, which is one of "all rooms", has acoustics problems....that you solved by positioning the speakers...and required no "treatment"?

My room, like all rooms, effects what I hear when I am listening.

Repositioning my speakers changed how the room interacted with the sound (which is now eminating from a different location and with a different primary axis of emission) to cause the sound at my listening position to be different than it had been before. I considered the change for the placment I ended up with an improvement.

So exactly how does that differ from my and Sean's et al, position?

You believe that rooms have no effect on sound. I am well aware that is not true.

What room "problem" did you solve (via positioning), that was directly attributed to the room (all of which have problems)???

For one thing, I reduced early reflections from the bass driver by moving the speakers out from the wall. I also reduced a couch that was interacting with the sound by toe-ing in the units.

Which ones are? Do any of the speakers used previously reveal the problems that must exist in the room?

I would hate to invite myself over if you don't like. This is going to be in your home, I'm the guest remember? Is your interest in having alien acoustic sources and beliefs in your room causing you to waver?

Let's just take a portable audio source you like to five-guys and crank it. We can compare it to out-doors.

So, in your reality and "thought experiments", your (untreated) living room is the (real world) rarity and an "all-concrete room (perhaps an indoor pool area, or a bathroom with hard ceiling)" would be the norm for a listening room?

Who said anything about "norm"? You keep asserting that rooms don't affect sound. If that's the case, then you should find no SQ losss playing your gear in a room of bare tile walls. It should sound identical to an anechoic chamber.

Could you please use the forum "Quote" function and quote exactly who said that? TIA.

No. Vastly overrated. The room is rarely, if ever the problem.

You then spend the next half-dozen pages simply dismissing the entire idea and leveling passive-aggressive insinuations against any statement to the contrary.

If you believe I've mischaracterized your position, and that you don't believe rooms have no effect: you've had ample opportunity to clarify yourself.

Having had several occasions to hear the exact same speakers in the exact same room before and after the carpet was replaced with tile: I know too well that "normal" rooms can have signifigant effect.

Tile bathrooms, something most everyone has been in, and which affect sound so much as to be unpleasent, are a good example. My earliest experiences were actually with things like overturned boats. Water really does nasty things to sound in small spaces.

 

[WmAx]

Like you, Yates has a very high opinion of himself. The difference is that he has designed and built several hundred Theaters and music rooms around the world. He also has the academic and real world credentials necessary to get those kinds of jobs. In other words, he walks the walk.

I do not know if he has changed his opinion on treating first reflection points but he downplayed their significance in my room and stated that he felt that was a conventional wisdom that is also a common error in treating some rooms.

I don't know anything about his self opinion, and I don't care about reputation of anyone, that's not of interest to me, and reputation/experience does not ensure one to be correct in and of itself. I was simply stating factual information regarding 1st reflections based on known perceptual research texts(which I have verified myself, and with many subjects), as I did not want people familiar with his writings to think I support treating 1st reflections indiscriminately.

I have not read anything from Yates in the past few years, so it may very well be he has revised his treatment methods for 1st reflection points.

There are also many speakers that the off axis response is perhaps beneficial to absorb/reduce in intensity. To be beneficial, the far off axis response should be very similar to on axis response.

-Chris

 

[PENG]

I believe arguing with AJinFLA is akin to arguing with a concrete wall. This makes sense, he doesn't want his concrete surface to be treated.

And he seems to think his wall is reinforced with Dr. Olive, if true that's better than re-bars.