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In room response

Hello, Lately I have noticed more talk of in room freq response measurements. It has been mentioned in regards to room treatment, subwoofers and their intergration, speaker placement, room size, crossover points, listening volume levels, speaker choices in regards to the type of music you listen to and a myriad of other reasons. I for one fell it is quite important and others seem to disagree to its importance in playback of recorded music.

This thread would be a great place for members to discuss its importance, ramifications, reason for being and to discuss results.

I have seen a few members who allready have posted results of the measurements under their "systems page". I just recently posted my freq response and waterfall graph on my "system" link.

I am quite sure that there are members who have allready done in room measurements of freq response, waterfall and RT60 or other measurements. If you are new to this, a program can be downloaded for FREE at the Home Theatre Shack, it is called the Room EQ Wizard. See link below. It would be used for mesurment only for our purposes, although it can be used with equalizers such as Behringer if you so desire.

http://www.hometheatershack.com/roomeq/

The only thing you need to provide is a sound level meter, which everyone should own, even if you don't use this program. A very inexpensive one is available from Radio Shack and is a welcome addition to any audiophiles toolbox.

I will start off with my freq response from 15-200 hz at 74db reference level posted here;
http://cgim.audiogon.com/i/vs/i/f/1208699468.jpg

Waterfall response 20-116hz posted here;
http://cgim.audiogon.com/i/vs/i/f/1208644826.jpg

Waterfall response 116-210hz posted here;
http://cgim.audiogon.com/i/vs/i/f/1208645085.jpg

Anyone else?

Bob
acoustat6
acoustat6 OP
357 posts
 
Hi Strabo, I see the pictures of your before and after in room response. I believe there is a substantial change for the better. You mention room treatment and speaker positioning as the two changes you made to get a better graph. Did you hear a change for the better? And do you think you could have made these changes (for the better) without using the REW?

Bob
holenneck
127 posts
 
http://cgim.audiogon.com/i/vs/i/f/1209053544.jpg

here is my in-room response
holenneck
127 posts
 
http://cgim.audiogon.com/i/vs/i/f/1209053544.jpg

the above response is taken with a USB microphone that is not accurate above 10k.

another big issue with good system setup is properly integrating a sub. Proper Phase adjustment is cruical.
acoustat6 OP
357 posts
 
Hi Holeneck, Thanks for posting! I have a few questions. You are using TruRTA which is obviously differnt from the REW software. My question is that your reference level seems quite low, if you look at the 1000hz freq it is at at approx 52db, which is very low. Is it possible to redo the level so you are measuring at a higher level such as the recommended 75 db as recommended by the REW? Otherwise it looks very good.
Thanks,
Bob
strabo
15 posts
 
Bob,
Yes, the changes definately cleaned up bass issues. Based on my original graph I had two note bass. Now it is much more even.

I wouldn't have even attempted this without the software. I did adjust my sub (used only for HT) manually once. It was a PIA and I never moved onto the mains. My first move with the software was to find an optimal speaker position within the reasonable options of my room.

The software quickly pinpointed problem frequencies. Next I used the tone generator to find the exact locations in my room of the problems and started treating those spots.

I have 7 major problem areas that I have attacked with fiberglass panels and one helmholtz resonator. There is an eighth problem area that is into the room a bit so I left it, but the rest were either in a corner, mid-wall, or quarter-wall. Some were at the floor, some were at the ceiling. None were floor to ceiling, and not all corners, mids, or quarters needed work.

I still have plans for more work on the seven areas. The forecast is for crappy weather for the next 4 days which may give me a chance at new measurements soon.
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