Concert Hall? Or Dedicated Listening Room?

Gs5556, I think that, in fact, the best sounding concert halls are rectilinear, i.e. the famous "shoe-box" configuration. They are, for the most part, smaller than the halls to which you have referred. Fan type halls are constructed that way as a means to get more people in the hall and not have them too far from the performers and therefore suffer acoustic problems that need to be corrected by all of those devices that you see in those halls.
Bob P.

When a sound emits out of a musical ensamble in a concert hall it must travel a great distance before it strikes a reflective surface. Also, if you notice the walls of some of the better concert halls ( Lincoln Center, Radio City etc.) you will notice a great deal of fabric on the side walls. When a sound emits out of your speakers it only has to travel a few feet (if you're lucky) to strike a reflective surface. This reflection depending on how far you sit from your speakers can reach you just as fast as the direct wave. This reflective wave is the one you are trying to minimize, for this will distort the music. You can also try to paint your room with acoustic paint.

The short answer is yes. Just design your listening room without any parallel surfaces and have the dimensions increase from the front wall back, much in the shape of a horn. This way, room modes and standing waves are eliminated.

Most all concert halls, movie theaters and ampi-theaters have width and height dimensions increasing as it fans out from the sound source. It's done so that every seat hears the sound at the same volume. Also, every stepped wall, ceiling and decoration has a purpose: to reflect sound to the seats.

If Carnegie Hall was a typical audiophile's rectangular living room, it would not be anywhere near as acoustically efficient. And then it would probably need those silly room treatments.

Many of the great concert halls are sized for the music, sound better with lots of people in the seats and actually have a lot of acoustic treatment -- sometimes the treatment is more obvious than other times. Often overlooked architectural offsets, uneven walls, curtains, etc. all contribute to the nice acoustics in these environments. Sometimes, the acoustic treatments are much more obvious and include large diffusers in the rear and side walls and ceiling absorbers.

In any event, size is a good place to start with a dedicated listening room. A 20Hz wave needs about 28 feet to accommodate half of it so, if possible, that's a good place to start. Reverb time is a function of the cubic area of a room, the surface area of the room and the absorbtion coefficients of the surfaces -- again, big rooms are good. Both reverb time and the nature of standing waves and reinforced nodes (i.e., where each of the room dimensions "support" or don't "support" certain frequencies) in, especially, smaller rooms contribute to the quality of sound. Generally, the treatments most audiophiles actively pursue are necessary because the rooms can't be designed toward an ideal from the perspective of size and surfaces. There is no perfect room dimension or character, but the great concert halls tend to follow similar sets of sizing ratios.

There are some great books (e.g., Alton Everest's books) and sites on the topic. One of the key principles have to do with getting the dimension ratios right: Some good ones are a) 1:00 to 1.28 to 1.54, b) 1:00 to 1.60 to 2.33, c) 1:00 to 1.40 to 1.90, d) 1:00 to 1.50 to 2.10 and e) 1:00 to 1.26 to 1.59. You want to avoid a cube (since all three dimensions reinforce the same frequencies) or any two dimensions being the same. Smaller rooms especially benefit from bass traps that could tone down some of the excess bass that is reinforced by the room. Other key principles have to do with reflection times (e.g., the rear wall reflects music back to you after you hear it from the speaker itself) and reverb times (i.e., how long it takes for the room to decay the sound by 60 db). Nothing is really simple about this -- e.g., an "ideal" reverb time for rock music is different than one for opera. Room treatments can also make a big difference in these, with diffusers affecting the nature of reflections and some treatments absorbing music quicker to give a faster, flater (across frequencies) reverb time. This is especially important at points nearest the speakers where the reflections occur first.

I'm a rank amateur on acoustics but I've found it very valuable to study up a bit before building my listening room. If you're in the process of constructing one, I would encourage you to do some reading (or hire an expert) to get the most out of it. Good luck on your journey.

this is dvd /cd done to the max
http://theshowreport.com/tunelandpics/BillWilkinspics/pioneerdv270/PICT0006.JPG

hi

Why don't you check out Michael Green ,check out tuneland ,they are beyond what you think ,if all you know about MG is the pillows,your in for a rude awakening...

Go to tuneland,check out these threads,Hiend1,Xavier,JIM,Bill,MG systems,cdimi,Doug ,Roy and so many more,20k-100k systems being sold,hi-fi is dead compared to the systems these guys have.

Interesting idea.

I think concert halls and many listening venues are designed to carry, transmit and accentuate musical performances. They create their own dimensionality and tonal character.

Reproducing music in our home is a different endeavor. For the most part, we're trying to recreate that performance by creating a listening environment that will convey its life without obscuring or interfering with it.

I understand your aversion to a recording studio like environment for a home listening room. I'm partial to a small study/library with a 2 channel rig. Something cozy.

CW, how cold is it where you are? I often lose perspective of winter being that I'm in Los Angeles.

"Problem" with that is that the acoustic of your listening room will interfere with the acoustic of the recorded space and the stereo imaging the recording engineer and producer worked so hard to capture. Think of listening to your current rig in a marble/granite tiled room and you'll get the idea. If you listen to mono recordings, or have Bose speakers, or you prefer everything you hear to be in the same acousic (like a cathedral), your concept could work very nicely. But if you want to listen to the recording to hear not just the music but also the recorded space in which the music was made and the characteristic sound of the musicians making that music, I would think that a room designed to sound like a particular concert hall would blur or even obliterate those cues. All that said, though, you really do not have to have a rubber-walled recording studio look (I couldn't stand that either) to get good sound--take a look at some of the virtual systems like Albert Porter's, for example.