Setting gain with multimeter issues

[maylar 10+ year member]

HOLD UP... I was WRONG!!! I forgot, it outputs 5v at volume 40. It is an eXcelon.

Yes, but not at zero distortion. 5 VRMS is the maximum you can get with a 14.1 volt DC power source. That's with the driver outputting rail-to-rail. Distortion is guaranteed.

 

[Mitchell Fosgate III]

I just installed a skar audio rp1200.1 amp and a skar svr 12 in a ported box. The sub has an rms of 800 watts at 1 ohm and the amp 1200 rms at 1 ohm. With my head units volume at 90% using a 40 hz test tone Spotify, I am having trouble getting the required voltage of 28.28 according to the formula of square root of rms x ohm. I put the remote base control knob at 1/2 and with the lpf at 100 hz the gain is past 3/4 max to get close to 28.28 volts. Is this normal? Sorry to sound clueless but this is my first sub/amp install and I want it to be right.

Great outlook to the problem. But the required voltage of 28.28 volts and using a 40 hz test means the changes in input to the OP AMP radio in your car is not dependent on the volts you mentioned. This means that 1 ohms you have has little resistances to any electrical changes going into the OP AMP. Setting the radio then is the issue. No way possible with your subs already added to your system. You'll get nothing out of it. The OP AMP and the radio is still the issue. Setting those first is the correct way to approach this problem.​

 

[ThxOne Premium Member]

If you order one of these meters from Amazon or the upgraded version with higher resolution display, setting your gains will be pretty easy. Also, order a second set of leads and an RCA connector like the one at the bottom of the pic. You can use it on the outputs of the head unit to find out how many volts it is outputting and the distortion.