Axiom Home Page Forums General Discussion Home Theater Fred's Excellent (hopefully) Calibration Adventure

Fred - did you try calling the folks at RealTraps? (http://www.realtraps.com/). I've seen multiple accounts at AVS Forum of them offering very complete advice once you tell them your situation. Of course they're going to recommend their own products to solve your problem, but it's at least a very good way to get direction on what is correctable using room treatment versus what is not. From what I've ready they'll give you a straight answer.

Jason

I havn't. Since I don't plan on buying any premade traps, I don't like to waste peoples time. Besides, I have seen Ethan Winer's opinions on a studio forum. Very seldom does anyone recommend resonator traps, even if they are acknowledged to be useful in some situations.

Fred,

What card did you use to perform your testing? I'd probably do this with a laptop but I do have a noisy desktop (already 'sounds' like a bad idea :D) as an option.

I downloaded the software and realized reading through the instructions I'll need something to tie my SPL in to the program.

Also...a stupid question. This is primarily to improve bass right? Or will this tell me about all my speakers?

-Nick

I used the mother board's onboard audio. What you need is both a line in and a line out. Mic in dosn't work.

Most people use it for bass, but with a better microphone, you can measure the full range.

If you are interested, read through the REW and calibration forums. Make sure to read the REW FAQs more than once. Everything you need to get you going is in there.

Line in, line out, no mic. Got it. Thanks!

-Nick

I believe if you are using a Radio Shack SPL meter you can get calibration files that allow accurate reporting of all frequency ranges or am I thinking of another program? It's late or early depending on your point of view, time for bed.

They have calibration files for several versions of the radioshack spl meter and for the galaxy mic.

Update:

I finally got around to sourcing some acoustic fiberglass and built myself some 2' x 4' x 6" panels for testing. The results were interesting.

The most notable items:

1. when I checked my calibration I noticed that I had lost 2db on my front right speaker. I noticed the side couch was out of place so I moved it back 6" so that it was now 25" from the speaker and got my 2db back.

2. I thougt I would try the two panels on the kitchen table (dining area) about 3.5' from the wall. The result was a graph about the same as putting both panels across the back corner floor to ceiling.

3. All of the positions eliminated the 42Hz hole.

4. I saw a +3db gain in the 22-28Hz area. Didn't think I would see any effect this low.

I am encouraged and will probably pick up another bale of acoustic glass soon.

I will post graphs tomorrow. Gotta get some sleep now.

I've always been a advocate of how acoustic bass traps and first reflection panels help the overall frequency in a room. It was obvious when I compared my before/after graphs. HT environments are no different than recording studio's when it comes to the positive outcome you see.

Yeah, but what do you do when you don't have room for corner bass traps, and only a couple first reflection panels? That is my dilemma, but I won't hijack this thread, plus I'd have to post pictures of my home theater, and any more it seems so lame compared to others...