Can room acoustics amplify the sound of speakers?

In attempting to solve some room acoustics problems, I have encountered a dilemma: Can room acoustics actually amplify the sound from speakers?? This is my scenario, I play music fairly loud, but am no headbanger (for example Yes' version of "America" or "Going for the One", Allman Brothers "In Memory of Elizabeth Reed") I understand what it means to pressurize a listening room and how recording venues have different degrees of loudness which should be adjusted or matched by the volume control. The source of this question originates when I play music loud, the dynamic passages become less clear and more congested or noisy, but a transition to a softer passage, the clarity and harmonics of the music improves. Am I hearing more total harmonic distortion at loud volume levels, and less so on the softer passages??, OR, is my amp clipping, or is the music's demands beyond the capabilities of my integrated amp. The amp is a Creek SE5350 Classic (80RMS) driving Acoustic Zen Adagios. The room is only 12X14. Will appreciate any advice or explanation. Jim
What often happens is room reflections either cancel or reinforce different parts of the musical spectrum. I have been using room treatments and found that by placing them in different positions the sound changes dramatically. Several of the companies offering room treatments give free advice; I got mine from Ready Acoustics and it has really improved my sound.
I agree with Stanwal.
If your room isn't accoustically treated at the first reflections, and preferably the second also, the nodes can make havok of the imaging and it will fall apart at high SP's.
If you don't have enough headroom in your amp this can also cause the image to fall apart at loud SP's.
And, if your speaker isn't capable of filling the room with said SP's, it will break apart.
And a combination of all the abouve will be evident
It is possible that the colorations you hear at high levels are actually present at lower levels, but are below the detection threshold.

In a small room, you inevitably have lots of early-onset reflections, and in general early-onset reflections are more likely to be detrimental than later-onset reflections. In my opinion it makes sense to address this situation at the speaker design level, rather than relying solely on room treatments, because room treatments are not frequency-selective enough to target the types of problems loudspeakers tend to have in small rooms.

For instance, if your tweeter has much wider dispersion than your woofer(s) in the crossover region, the reverberant field in your room will have excess energy in the lower treble region, at the lower end of the tweeter's range. This is more likely to color the tone and degrade the clarity if the reflections begin arriving relatively early, as is the case in a small room. Absorptive panels cannot target just that frequency region; they will absorb broadband, and enough absorption to eliminate the coloration may also make the room too "dead". Some absorption will probably be beneficial in your case, but in my opinion it's easy to over do it in a small room.

The fact that you're using the word "amplify" makes me think that you may indeed be getting emphasis in the 3-4 kHz region from the reverberant field, as that is where the ear is most sensitive so extra energy in that region would seem to amplify things.

Imho, ime, ymmv, etc.

Stand in your room and clap your hands. If it echoes, then the same thing is going on on every note that comes out of the speakers.
Keep it simple at first and progress by process of elimination.
I've chased and solved the very same problem in my own system and it wasn't the room acoustics ... see if this is similar

You system sounds wonderful 99.5% of the time does everything right from sound staging to top to bottom coherency ... nothing sticks out or glares in the midrange and extreme's ... top and bottom end are extended and well defined

Everything sounds fine until there is a very brief and powerful peak/passage (Crescendo) called for, that demands a large draw of current for a very brief period

Hint ... it isn't the amp clipping or it would be shutting off briefly

For that brief nano second or so ... the whole presentation goes to Hell in a Hand Basket ...

The sound stage shrinks to a small ball in between your speakers ... the sound congels ... it ESPECIALLY sounds like someone is shouting rather than singing ... and dynamics get looped off on the trailing edge ...

You also notice that this happens only on PEAKS and is not connected or related to any normal upper octave frequency brightness

It's like you're driving down a very smooth highway at a high rate of speed and you hit a deep pot hole abruptly ... and it's over that quickly

The problem of the brief shouty-ness is probably caused by the OPAMPs in the CD player's SS output stage not being able to deliver enough current to drive the IC and the load on a strong PEAK and they loose their linearity momentarily when placed under the high demand for current during the PEAK/Loud passages

This is not an issue of impedance or voltage mismatch between components ... it is the Op Amps distorting because the can't deliver the current required in that brief high demand period

When the music becomes demanding, the OPAMPs will loose their linearity for a brief moment, distorting and that distortion then confuses and causes the Negative Feedback loop, to oscillate and ring while trying to maintain the signals integrity from input to out put

The negative feedback loop try's to maintain the signal from input to output but when the chip OP Amp run out of deliverable current for that nano second on a PEAK and distorts .. the negative feedback loop picks up the distortion and starts oscillating and ringing for that brief moment that the Op Amps can't maintain the needed current to dive the intergrated and are out of linearity

The ringing which is very brief, and only on the peaks of demanding passages is perceived as "Shouty-ness" and seems to be pretty common with CD players that use SS output stages with chip OPAMPS ... although I don't think many are aware of it or blame the problem on something else

Here's more proof ... no matter what volume you are listening to your system at ... low, medium, or high ... this distortion and shouty-ness will be present on all strong peaks as it is the Op Amps in the source causing the problem and sending the distortion to the next component ... the intergrated amp ... and not the intergrated amp's lack of power because the distortion is still present at low listening levels on the peaks ... so the amp can't be running out of power at low and medium listening levels

If this sounds like your problem ... tell me what you use for a source and I might have the solution ... and if this does not sound like your problem ... it's a good thing I put on my Flame Suit and Eye Protection on
Zmanastronomy, good advice.

I think you hit the proverbial nail on the head. Burson audio is a firm believer in the drawbacks and limits of opamps and they keep them out of their product for some of the very reasons you state. Since acquiring their integrated, I've noticed and appreciated the dynamic scales it reproduces with aplomb. Nothing congeals or shrinks in scale: it just goes louder and sometimes startles me.
A bit off topic, but like many other things, not all opamps, and not all opamp applications are the same.
Just last night we compared my SS Dac with , I believe, 5534s with a $9K tube dac. No contest. Saying all op amps are bad is like saying all tubes are bad, all cone speakers are bad, etc. If there is one single rule in audio it is that APPLICATION IS EVERYTHING. Great designers can use average parts and get the most of them, bad designers can make ANYTHING sound bad.
Which DAC was the better? I'm thinking the $9000 tube dac, but in this game you never know.
nonoise ... my post comes from direct experience of having a very well treated room with a good response curve but the same annoying shouty-ness and congestion that Sunnyjim is complaining of

I swore it was the far wall barking at me and then I read a blurb about op amps fading and getting shouty ... I added a current dividing SS outboard buffer and the shouty-ness and congestion went away

So I switched the player and the buffer for a player that has a SS class A no negative feedback J/Fet analog out and now have plenty of current and no feedback system to muck things up

Un and Stan Duke and Zman ... Let me try and tidy up a bit

I will be the first to agree that until you neutralize the negative effects of the room ... you're shoveling ---- against the tide

Until that room's negatives are corrected you can't really know the full potential or real signature of your equipment


On Op amps ... I should have made it clear that the ones I were referring to are the ... all circuits on one, everything on the head of a pin with power supply type intergrated chip that have trouble remaining linear ...

There are also discrete Op amps made up of anywhere from 20 to 40 individual components on a board to build a single op amp circuit to perform tasks ... much more robust ... but you don't find them in a most CD players, especially Sunnyjim's Rega

Yes the industry loves the convenience, ease of implementation, size, low cost, and all in one architecture of these darling pin head all in one CHIP OP AMPS

Agree with Stanwall that many talented designer can find alternative ways to skin a cat .... but I strongly suspect Sunnyjims cat is mea owing because of that all in one chip in the analog output
Davehrab. Well said.
This is a very interesting topic as I notice the same problem with my Vandersteen 1Cs. At low to moderate levels they perform exceptionally well, but if I turn the volume up to far they lose the magic. Now with my Soliloquy 5.0s this does not happen. I can play them much louder with no noticeable change in tonal character. In fact, with the Soliloquys I seem to listen at much louder levels simply because they keep the magic.
I'm reading Duke's contribution with interest as I always thought it was simply an overloaded room. But if two different speakers act so differently in the same room, in basically the same position, there must be something else going on.
My room is approximately 11X13 with treatment in place. I'm working on dialing in the best placement for the 1Cs and fairly small changes have made significant differences, especially toe-in.
The tube one is up for sale. At least in this system the SS DAC was better; YMMV.

The Vandersteen's tweeter crosses over a little lower than the Soliloquy's, and does so with a more gentle slope. The Vantersteen's tweeter is a bit smaller in diameter than the Soliloquy's (1.0" vs 1.125"), and the Vandersteen's midwoofer is considerably larger in diameter (8" vs 5.25").

These factors contribute to the Vandersteen's tweeter putting out more energy to the sides than the Soliloquy's tweeter, while at the same time the Vandersteen's midwoofer is putting out less energy to the sides. So in theory at least the coloration-inducing effect of early onset reflections is likely to be worse with the Vandersteens.

If my hypothesis applies in your situation, increased toe-in should reduce the "room overload" effect by decreasing the amount of energy in that first reflection off the near side wall.

I want to thank everyone who has contributed to this thread; I have learned a great deal about the electronics of op-amps. My walls are "not barking" at me yet as Davehrab noted about his back wall, but the shouting has not stopped. Two questions emerge from the responses to this thread. First, Why don't high-end audio stores encourage an acoustic evaluation of a buyer's room; surely, they could provide their own acoustic treatment service, or just sell the product on a DIY basis and create additional revenue, for themselves, especially in these tough economic times, Second, it would be interesting to find out how many manufacturer's rely on a "one chip" output configuration Davehrab suggested of the Rega Apollo. If that is the only cause,and not a combo of CD output design and not resolving the negatives of room acoustics. How many of us, just guess at acoustics, or assume that the overstuffed furniture in the living room will cure all the negatives. I can only remember once over 38 years of audio clearly hearing the difference created by two floor to ceiling bookcases behind both speakers that "dramatically" changed the sound.

I would like to contact Rega, and see how they respond to explaining this "problem" of an apparent uncontrolled increase in volume, resulting in a loss of clarity on dynamic passages. I am not sure I understand how Davehrab would solve the electronic problem of overloaded or overworked op-amps. How much could it possibly cost a manufacturer to eliminate this problem. I am sure buyers would pay a reasonable increase in retail to attain good sound. Jim

Your thought of audio chains (at least upscale ones) providing room treatment advice with the purchase of equipment and not offering it is a good one. Just one look at the 'Geek Squad' for computers and HT installations merits a good look at the concept. Most stores don't have the resources of a Best Buy but they could at least aid in setting it up and advising. When I got my speakers, the guy who owned the place where they were auditioned came over to deliver them and later on suggested at least one sound panel for the side of my room that was filled with windows. And this guy operates out of his house and doesn't even make or own the speakers. He's just a great guy to do business with.

On the matter of the Rega being the source of your woes, if it is determined to be the opamp in the unit, it can be swapped out for a better made one or even a Burson discreet opamp. Burson has testimonials and tutorials over at their website. Hope this helps.
My walls are "not barking" at me yet as Davehrab noted about his back wall, but the shouting has not stopped

Consuming large amounts of Gin and Corn Chips at mid day lead to colorful metaphors ...

Shouting is the correct word and symptom ... also substitute Congests for Congeals in the first post ... they are not the same thing and congests momentarily is what it does

Why don't high-end audio stores encourage an acoustic evaluation of a buyer's room; .... and create additional revenue

For years the industry has made money in spite of itself ... it didn't have to offer anything additional to be profitable and stay in business

A up sell (Room Acoustic) purchase after the initial sale may void the whole deal because there is a chance you will balloon the customers budget and lose the entire sale

Most sales seem to be predicated on price and position in Stereophile/Absolute "Recommended Components" list ... gives you very little to sell with

Try pitching the features and the benefits and educate and informing your buyer

Note to Sellers ... sometimes "I don't No" mean "I don't Know" .. and needs some aditional educations to change the "No" to "Know"

I think there is 3 things every buyer wants and deserves ...

Price .. Service .. and Availability = Real Value

Second, it would be interesting to find out how many manufacturer's rely on a "one chip" output configuration Davehrab suggested of the Rega Apoll

If you knew you would faint ... it's the weapon of choice in over 90% of the sub $2500 and down machines

Don't task me ... just contact the mfg of your player and ask them if they use a chip or discrete op am in the analogue out section of their player

Now of course they are going to deny any such problem exits with this Chip Op Amp ... but here's where you have to trust your Ears (What you Hear) vs your Eye's (What you read)

How many of us, just guess at acoustics, or assume that the overstuffed furniture in the living room will cure all the negatives

"Knowledge without understanding is a direct path to failure"

How many do you think put the effort into the self education like Duke did ... we all started with the same amount of knowledge ... NONE

I am not sure I understand how Davehrab would solve the electronic problem of overloaded or overworked op-amps.

I can give you 4 suggestions ... Good Better and Best and Replace ... but lets see if anyone else can offer a solution before I commit

How much could it possibly cost a manufacturer to eliminate this problem. I am sure buyers would pay a reasonable increase in retail to attain good sound.

It's not as easy as just fixing ... My Ayre D1EX was $8600 ... that fixed it

I don't think it's as much a price thing with Mfgers as the universal (ality) of the chip .. multiple application on one chip for ease of implementation, and convenience for building and mfgering are probably more the reason at this price point component
I do rememeber reading how each reflective surfaces adds 3db to the bass responce. (Notice it is not a power gain, just a shift in Hz responce). So, relative to your seating posistion, 3db for floor, 3bd for backwall**, 3bd for sidewall**)

** if speaker is "too close" to back or sidewall.
It is quite true that most of the chips used in current CD players were designed for other applications and have significant shortcomings in CD use. Rega deserves credit for trying to use a chip actually designed for CD use by a small English company. I believe the company went under but not before Rega bought a good supply of the chips. Their new high end player, called the ISIS I believe, has gotten some very good reviews and their lower price ones do well in their price categories. Right now many of the top specialist manufactures depend on NOS parts; this obviously cannot last indefinitely.
Stan .. appreciate you coming back and offering support to my theory on sunnyjim's problem

Initially I know s/j was a bit reluctant to accept what I put forward vs the Industry but ... with your post and support I'm sure he feels much better now about accepting what the problem is and now just has to resolve it

Also appreciate you removing all self interest when giving subjective opinion on this one .... has to be tough to get caught between consumer and industry ... but today I think s/j came out the real winner the way it's supposed to happen in this forum