Why don't you use an SPL (Sound Pressure Level) meter?

[Kurt C.]

. No offense to anyone please, but afterall we don't use a lux meter to tell day from night!

Check this out. After several of us exchanged friendly jokes about day/night/eating/starving, I found the following quote in the minutes of the Boston Audio Society. The quote has been shortened by me, but nothing was added:

ABX Testing--A sample article from the archives of the B.A.S. Speaker From the December 1990 meeting, BASS Vol. 19 No. 3
Preliminary Discussion by E. Brad Meyer
(stuff deleted)

Tonight Meyer was going to focus his attention on the very end of the chain: the listener. Many things affect how a listener perceives the sound. Among them are hearing limits, experience, fatigue, mood (one's own and that of others), and pharmacological substances both medical and recreational. Ambient lighting affects mood and is thus a factor, as Meyer discovered early on in his audio pursuits. Lighting just the speakers and leaving the rest of the room dark makes the sound more vivid and dramatic. Meyer suggested that people try this, and also darkening the whole room. End of quote.

Funny huh! If interested, read the rest of the article here.

Even if you haven't heard of the Boston Acoustic Society before, you'll recognize a member of the society mentioned at the end of the article--Dr. Poh Ser Hsu.

[sensibull]

I wasn't expecting much of a difference because it was only one 2X4 foot panel. However, my subjective impression is that the improvement is amazing. Dialog sounds much clearer and is far easier to understand, even at low volume levels.

Here's a little tip along these same lines that I stumbled upon completely by accident... My living room has four sets of windows across from the HT setup, so until recently trying to see the TV during the day was murder, even with the curtains closed. I also knew those windows was affecting my sound, but didn't know how much until I bought some of those "black out" panels they sell at Bed, Bath, & Beyond. No idea what they're made of, but it's a very dense heavy material that *completely* blocks out light. You rig them behind your existing curtains and they're very inconspicuous. Anyway my system sounds a LOT better with those curtains closed, so its a great way to kill two birds with one stone.

[Abhi]

I've been thinking of building bass trap panels using these:
http://www.bondedlogic.com/ultratouch.htm
I don't have enough tools and carpentry skills to make them. Any alternative ideas on building the frame? May be we should have a separate master thread/category for room treatments.

[Kurt C.]

We've started a thread here

Sensible sound solutions sells cotton acoustic absorbing material similar to the stuff you linked to at very reasonable prices. He also sells pre-made panels that are quite inexpensive.

I was recently given an 8-pack of 2X4 foot, 1.5-inch thick fiberglass panels, so it was slightly cheaper for me to build them myself, but I don't think the finished ones look as good (or cost much less for me to build) than the 2-inch panels from Sensible sound.