i just went out and purchased a multimeter so i could set the gains properly on my amp. i unhooked my subs, put on a 50hz test tone and turned my stereo up to 24/35. i put the multimeter plugs into the -/+ terminals to test voltage and all i got was 3 volts. I turned the amp up 3/4 of the way and it only gave me 9. any ideas as to what could be the problem?

That's what the gain does, it amplifies input voltage. Adjust the gain to match the output voltage of the head unit.

That's what the gain does, it amplifies input voltage. Adjust the gain to match the output voltage of the head unit.

x2, and you shall be set.

That's what the gain does, it amplifies input voltage. Adjust the gain to match the output voltage of the head unit.

x2, and you shall be set.

i thought it was supposed to match up with the chart like JL's website says, where 600w at 4 ohms should be 48.9V

edit: i have a 1000w rms amp, and im trying to get it more around 5-600 so my stock electrical can keep up with the output until I can purchase the wiring for the big 3 as well as a new battery.

Edited February 11, 201015 yr by Third Eye Vision

Are you using a CD with test tones? Turn the volume slightly about maximum listening levels, then adjust the gain to the correct voltage or less.

There is no way to set your amp to only do 500-600 watts, you are in control of the volume knob you don't have to always get 1000 watts out of our amplifier.

Are you using a CD with test tones? Turn the volume slightly about maximum listening levels, then adjust the gain to the correct voltage or less.

There is no way to set your amp to only do 500-600 watts, you are in control of the volume knob you don't have to always get 1000 watts out of our amplifier.

yeah I made a cd with test tones, 50hz for my subs, and the rest are to match my eq on my deck. I read the pinned article on here on how to set amplifier gains and thats what I was going by. The calculations explained how to "gain down". Like if you had an amp that put out more than your subs, to do the math by the rms of your subs. Which is what I'm trying to do. His example was 100w x 4 ohms, and the square root of that was the voltage you wanted to set the amp to. For that setup it was 20v, I did mine at 600 x 4 ohms, and I got 48.9v. I matched it up with JL's website and their tutorial explained the same thing, only their target voltage was 31.6v. I must be understanding it all wrong.

First thing I would double check is that you have the DMM on the correct measurement setting (Vac) and range setting.

If it still doesn't work, toss the DMM back in the toolbox and set the gain by ear.

Definitely make sure you have it set on VAC. Next, if you have a subwoofer level control, turn it up to where you normally run it at. You don't want to set your gain at a lower setting only to turn that setting up while listening. Then you are putting out much more than what you had planned.

The reason they say to disable EQ options is because if you set the gain with a frequency that is boosted by the eq, all other frequencies will lack power. The subwoofer level control is exempt from this rule.

Thanks for the help guys, I set it to 4 volts since that was what my head unit says it is. It sounded pretty weak, then I remembered i had the subwoofer level on the deck turned all the way down to -15. so i turned it back up to 0 and it sounds good. I'll have to readjust everything later, but I turned on a song that hits good and the voltage didnt drop below 13v so I think I have it set pretty well. I'll have to check it again later since I only let it play for about 30 seconds, it might drop more if I continue to play.

edit: i had the dmm set at VAC 200

Edited February 12, 201015 yr by Third Eye Vision