I was playing around with my Radio Shack SPL meter today. I was measuring the sound in my home theater, using only the front speakers and a sub. The meter was set at 80db, C weighting, slow response. I used the Stereophile Test CD #3, tracks 17, 18 and 19. These tracks use 1/3 octave warble tones.
Below are the results, with and without meter corrections done by Michael Sims of Prairie State Audio Construction Society. My numbers may not be that exact. This was actually a test before I examine my main listening room and main stereo.
By the way, my home theater is 17X12 with 9 foot ceilings and hardwood floors. There are windows against my back wall (behind the TV and stereo) covered with curtains. The only furniture I have in the room is a couch. Needless to say, this is a very live room. Uncorrected Corrected
20Hz 76 83.5
25Hz 83 88
31.5Hz 81 84
40Hz 76 78.5
50Hz 73 74.5
63Hz 81 83
80Hz 86 88
100Hz 87 89
125Hz 85 85.5
160Hz 82 81.5
200Hz 82 79.5
250Hz 80 84.5
315Hz 84 82.5
400Hz 84 84
500Hz 84 83.5
630Hz 81 81
800Hz 82 82
1khz 81 81
1.25Khz 80 80.5
1.6Khz 81 81.5
2Khz 79 77.5
2.5Khz 79 77.5
3.15Khz 81 79.5
4Khz 82 80
5Khz 84 82.5
6.3Khz 86 84
8Khz 79 87
10Khz - -
12.5Khz - -
16Khz - -
20Khz - -
If you graph the numbers, there is a peak at 25Hz, a dip at 50 Hz, and another peak at 6.3Kh. A dip starts at 8Khz and continues down and off the scale from 10Khz to 20Khz.
Can anyone tells me what these numbers mean? Is it normal for speakers to fall off at 8Khz on? The only room treatments I am considering are Risch DIY tube traps and HF panels. Will these help?
Any suggestions would be greatly appreciated. Thanks.
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