I know ive goto tune the box as close to the resonant frequency of the car as possible(correct me if im wrong) to gain the highest SPL. I believe this is around 60-65Hz??? how can i measure this and do i tune the box to the exact frequency?
Also in WinISD is the Gain window more important or the SPL window, does anyone have knowledge of this program and could they please advise me?
Replies (1)
Swez on 06/14/2003 09:35:48
I have little background in SPL COMPS tweaks but "believe" you can determine the approximate resonance of your vehicle with an SPL meter and a test tone CD. Not fast sweep tone program material, but incremental tones of 5 -10 seconds each. (1-3 Hz increments)
May I suggest a calibration reference, where you start with a test tone of say... 45 Hz and set you HU volume so that you get a steady 90 dB reading. It does not have to be super loud, to find resonance.
Then, run the test tones between 40 - 80 Hz and jot down your SPL meter readings at each tone value. When you approach resonance, the meter reading will climb until a max value reading is noted. As you pass the resonance target, the SPL numbers will begin to taper off again. The range where SPL #'s are highest, is your target resonace range. That high number represents resonance and peak output of your subs.
If you like, repeat the test again at a higher SPL level say 110 dB and see if the original plots remain in similar relationship to the first plot.
Again, I am not into SPL for the sake of competition... but this is similar to the technique we use use in finding room resonances for fixed or portable sound reinforcement systems. We generally use an RTA (Real Time Analyzer) and pink noise generator to find room peaks. Then, we filter out the peaks noted for a "flat" (as possible) SQ plot on the RTA.
If anyone had any other recommendations... please jump in and have at it.
Swez
Also in WinISD is the Gain window more important or the SPL window, does anyone have knowledge of this program and could they please advise me?
Replies (1)
Swez on 06/14/2003 09:35:48
I have little background in SPL COMPS tweaks but "believe" you can determine the approximate resonance of your vehicle with an SPL meter and a test tone CD. Not fast sweep tone program material, but incremental tones of 5 -10 seconds each. (1-3 Hz increments)
May I suggest a calibration reference, where you start with a test tone of say... 45 Hz and set you HU volume so that you get a steady 90 dB reading. It does not have to be super loud, to find resonance.
Then, run the test tones between 40 - 80 Hz and jot down your SPL meter readings at each tone value. When you approach resonance, the meter reading will climb until a max value reading is noted. As you pass the resonance target, the SPL numbers will begin to taper off again. The range where SPL #'s are highest, is your target resonace range. That high number represents resonance and peak output of your subs.
If you like, repeat the test again at a higher SPL level say 110 dB and see if the original plots remain in similar relationship to the first plot.
Again, I am not into SPL for the sake of competition... but this is similar to the technique we use use in finding room resonances for fixed or portable sound reinforcement systems. We generally use an RTA (Real Time Analyzer) and pink noise generator to find room peaks. Then, we filter out the peaks noted for a "flat" (as possible) SQ plot on the RTA.
If anyone had any other recommendations... please jump in and have at it.
Swez
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