Hi folks,

I recently wired up an amp and sub in my vehicle. I attempted to set my amp levels by monitoring AC voltage at the bridged speaker outputs while increasing amp gain. I was using a 50 hz test signal at 75% HU volume for the calibration. Strangely, I found that my multimeter reported lower voltage with increased gain, though I have suspicions my multimeter isn't that good. Here's the equipment in question:

Amp: Alpine MRV-F345 (http://www.crutchfield.com/S-zArRnSojO3i/p_500MRVF345/Alpine-MRV-F345.html)
HU: Pioneer DEH-P5800MP
Sub: Pioneer TS-2541D 10" shallow sub
Multimeter: CT Digital Multimeter(http://www.canadiantire.ca/AST/browse/4/Auto/AutoTools/MultiTesters/PRD~0251031P/Digital%2BMultimeter.jsp)

Any thoughts as to why the voltage would go down?

 

my uneducated guess would be when your turning up the gain on your amp its reaching a point where your electrical cant handle it and there is voltage drop thats just a guess tho i dont know much

 

I'm going to try to get my hands on another multimeter to confirm, but that sounds like as good a suggestion as any. On the plus side, I'm happy with how everything sounds, I'd just like to ensure I avoid clipping.

 

It could be a few things happening, if your meter is set for AC and the amp starts to clip (DC voltage) your readings will differ. The only way to set amplifier gain properly would be to use an oscilloscope and watch for squaring of the signal (DC voltage on an AC waveform).

After you've set your head unit/sub amp/mid & high amp gains to not clip, don't be afraid to lower any of the amp levels to match a nice smooth blending of outputs. This is all a mater of taste, some prefer to have it level, some prefer their bass to be a few times louder than everything else

Hope this helps!