After a year long offensive, my troops have taken over the never-used dinning rooms and established a HT beachhead. Ran the surround wire through the walls this weekend, so its time to tweak. It is a small room (15x12.5x9), so reflections abound, but it already sounds much better than the prior placement in the multipurpose/multi-portal den. I'm building some sound absorbing and dispersing panels for the walls and am looking for some free help on the placement. Also looking to position the sub, chairs, etc. (1) Please recommend useful/friendly software or a good source of free advice for figuring out the various modes, reflections, nulls, etc? Over the years I have probably seen the answer to my question a 100 times, but when I need it just can’t find the answer. (2) Please point me in the direction of the best checklist for effective setup. I.e., best value in test disk, SPL meter, best procedures, test materials, etc. Thanks in advance for the help.

I have no useful advice to offer since I haven't treated my room, but want to mention a sudden and curious desire to drop everything and watch Saving Private Ryan.

Did the first 20 minutes last night! I can still feel the saltwater spray - and bullet wounds. But I noticed I must have a null at very low Hz around my seat as the bass was not what I expected, yet on other soundtracks I have had to lower the SW to defeat some booming. Hoping a few fiberglass boards and a SW move can help this, but I'd rather have a plan as opposed just sticking homemade panels all over the walls.

The best software for room testing would be REW. It can be found at hometheatershack.com. You will need an spl meter and a small bevy of cable. No test disc is required since rew has its own tone generator for sweeps. The program has calibration files for the newer analog and digital radioshack spl meter. if you want more accuracy or to run full range sweeps, you would need a proper mic (the rew folks recommend the Behringer ECM8000).

Both hometheatershack.com and audioholics.com have forums for room setup that I have found useful.

Hope this helps.

That does, thank you. I'll dig in.

For the lazy....
REW Forums at HT Shack

Charles, I'll comment on a couple of the points raised. For an SPL meter get the Radio Shack digital model, which is easier to read and has additional measuring modes that the analog meter doesn't.

If you're planning that fiberglass boards will be significantly effective at low bass frequencies, you'll need a lot more of them than you're probably thinking. As Dr. Toole points out, fiberglass or foam panels would have to be very thick to be effective at very low frequencies. The requirement would be about 1/4 wavelength, which at 40Hz, for example, would be about seven feet. There are other types of traps which use resonant membranes to absorb some of the bass energy(as more flexible walls also do)and which are more effective(but also more expensive)at reasonable sizes than fiberglass or foam.

Dang!! I am just getting my toe into this treatment area and was hoping a few panels in the corners and on some of the obvious points of reflection would make a small room act a bit larger, and even out my low frequency fear. As my room is not a uniform rectangle, most of the software for modes looks pretty useless for my room. I guess I need to get the REW software, the SPL meter, a mic, an external sound card (for laptop) and run some test tones. I assume I should still put absorbers at the first order reflections and diffusers at the rear? Right?

I clearly have just enough knowledge to frustrate the bajeezes out of me.

Welcome to the club! We have just been at it longer, so we have learned that getting frustrated is normal and have learned to accept .

On the up side, I am very happy with the sound improvement gained by moving my whole HT into this smaller, but more enclosed, room. If I every had any doubt about the impact of the room on the sound, this cured that. Bass is tighter, mild ringing in the highs is gone, and dialogue is clearer. Still working on imaging. And for video the greater ambient light control has drastically improved the blacks on my RP DLP.

Perhaps I should enjoy the darn thing and stop looking to tweak it? Nah, I must tweak.