Axiom Home Page Forums General Discussion Home Theater Room Shapes

Many good points have been mentioned regarding treatments. I spent nearly three months modelling and experimenting with acoustical panels at the reflection points and building bass traps. Anyone who wants to improve the sound quality of their HT room should carefully treat their environment. Its a highly effective way to optimize sound reproduction. It doesn't have to be expensive and it can be tastefully done as Randy has shown.

Existing furnishings like bookshelves at the rear and side reflection points are excellent for sound dispersion. Rugs on the floor or blankets on hard funiture are easy quick treatments. Heavy velvet curtains around the sides of the screen are another easy treatment which adds to the theatre like look.

And the more bass traps the better. I have four floor to ceiling traps in each corner as well as several at wall ceiling corners and that has been the most significant sound upgrade to my HT. I may build several more though the room is already "studio-like" according to most visitors.

Taming the first and second reflection points is an important objective if one is to achieve excellent sound in an HT. I agree one has to be careful not to overdo treatments along the walls but placements at the mirror images along the walls and ceiling do indeed get rid of smearing from the main channels as a result of delayed sidewall and ceiling echo. That phenomena is different than optimizing spaciousness through off axis dispersion, an important attribute for the side/rear surrounds. I found coverage of about 25% of the wall area with teatments did much to tighten up and clarify bass and mid-range. The upper mids and higher sounds benefited greatly from absorption at the first reflection points.

For strictly stereo listening I have opted for a spacious vaulted room with far away reflection points so speaker placement/toeing and listening position are the primary acoustical determinants.

Oh yes. A strategically placed rug, armchair and bottle of cognac can also be very effective in dulling those reflections.

>>I also never meant for my comments to be taken in a harsh manner. If they have then I appologize

No worries. It's been months since our last good cage match.

>>For strictly stereo listening I have opted for a spacious vaulted room with far away reflection points so speaker placement/toeing and listening position are the primary acoustical determinants.

I can vouch for how good that room sounds. "Majestic" was the first word that popped into my mind when the music started.

Acoustic treatment is a fairly new subject for me but after listening to all you guys banter and learning from your posts, I feel like a pro. I haven't yet started the room treatments but like I said before, by carefully locating the speakers and tuning with test tones, I have made a monumental difference in sound quality. I can honestly say that it is now very easy for me, and my wife, to distiquish a good studio recording from a mediocre recording from a reference recording. I could never do that before and I didn't even think my wife listened that closely! I have been listening to "supposed high quality" equipment for a long time and never noticed such recording discrepencies.

Nice of you to say John. I'll have to have you over again seeing how you inspired me to replace the Arros with QS8s. Much better soundfield. This time I buy the exotic beer.

I've been toying with a Cary Audio slp-98 tube pre-amp in the stereo. Looking forward to your impression.

John and John,

Thank you so much for all your feedback, sometimes I wish I came across in the same manner as both of you. I know I admire and look up to your knowledge. If I ever make it up to your neck of the woods, I hope I get a chance to meet you in person.

Also, your inputs on the whole treatment subject have helped me greatly understand what I'm experiencing, now if I could only retain all of this.

>>If I ever make it up to your neck of the woods, I hope I get a chance to meet you in person.

I think we would be mighty PO'ed if you were in the area and didn't visit...

>>I haven't yet started the room treatments but like I said before, by carefully locating the speakers and tuning with test tones, I have made a monumental difference in sound quality.

This is a great place to learn, isn't it. It's one of the few places on the internet where I can ask a dumb question and get a careful, helpful answer...

>>I can honestly say that it is now very easy for me, and my wife, to distiquish a good studio recording from a mediocre recording from a reference recording.

It's a little scary at first when you start hearing good vs. bad recordings. "There's something wrong with my system... now it's good... now it's bad... oh, it's the recording"

Going back to the "room shapes" topic for a minute, after catching up on sleep I think I can make a more coherent argument.

As others have said on the thread already, there are limits to how much of a performance can be captured in a stereo recording. In particular, you can't capture 3-dimensional effects (the acoustics of the room where the performance took place) except to the extent that they can be projected onto a single dimension (the axis between the speakers).

You can capture some of the reverb and reflections of a great hall but the most you will get on a stereo recording is a bit of reverb and a small portion of the spaciousness.

Anything else, if you want it, needs to come from the room. Now, a reasonable question pops up -- do you want the same "spaciousness" when listening to a jazz trio that you wanted when listening to Handel's "Messiah" ? The answer is "probably not, but your room doesn't sound *that* big anyways"

Spaciousness and soundstage are different (duh ) and they need different things out of a room. You need a bit of control of first reflections to preserve soundstage (or, presumably, a room which is quite wide relative to the speaker spacing so that your brain can filter out the first reflections) but you also need a bunch of reflection off the side walls to get that ambience and spaciousness.

To be blunt, the recording engineer gives that up when they mix in a dead room, BUT they are probably doing the right thing for the listener. We don't want the recording engineers mixing in awful two-dimensional echoes to do a crappy job of simulating the original venue -- their job is to get the music accurately and tightly represented on the recording to the best extent possible in a two channel environment -- our job is to add the 3-dimensional ambience which you can't get through a 2.0 recording anyways.

The next interesting question is obviously "what about 5.1". The answer is equally obvious -- "I don't know". A 5.1 recording gives you a second dimension -- front to back -- but still doesn't give you the third dimension.

I designed my new house to give me that third dimension. John moved his stereo system into the great room to get that third dimension. We buy QS8s over other surrounds to get that third dimension.

Where do the other speakers go in 10.2 anyways ? Hopefully some of them are above or below the standard 5.1 set...

Ahh, here we go. General consensus seems to be that the most important additional channels in 10.2 are the "high left" and "high right", which provide most of the spaciousness and allow the listener to compute the size of the original venue.

There seem to be 14 channels in 10.2, not 12. Apparently the 10.2 moniker is meant to indicate that it is "twice as good as 5.1", even though the format is actually 12.2 not 10.2. Go figure.

Interestingly enough, nearly all of the added channels are intended to "convey the sense of spaciousness which can not be properly reproduced in 2.0 or 5.1".

In other words, if you are going to build a dead listening room you probably want to think about pre-wiring for those extra channels right now

12 channels? pffft! I already pre-wired 14!

-Hutz

Well then, my friend, you are "10.2 ready".