Once again I found the need to play around with the settings on the Servo amp running on the Super V's. Wife is away for several hours, so I can get away with Test Tones. Pulled out my old Radio Shack digital SPL meter and the Alan Parsons & Stephen Court MFSL Sound Check 2 CD along with my printed copies of the settings sheet for the Servo Amp, ready to go to town. I've noticed it before, but decided to see what specific techniques people use to get their best ("most accurate") readings. I run only one channel at a time and am measuring from my main listening position with the meter held at the approximate location of my head with the microphone pointing mostly straight up, but tilted slightly forward towards the speakers (straight forward between the speakers, not directly at the one being tested), in the "C Weighting" position. I hope this is all correct.
I notice that at the lowest frequencies of the CD (20 &25 Hz), the readings jump all over the place, well in excess of 10 db.
- is there a way to minimize this a bit?
- should I be doing something different?
- is slow or fast response more accurate at these low frequencies?
I know the RS meter is way off at those frequencies (I usually read 4-5 db at 25 Hz and 6-7 db at 20 Hz), but I'm still confused as to what I should use as my actual reading when it's swinging back and forth so much.
If I should post this in the Acoustics Forum, please fell free to move it. Thanks.