AronZ28

iTrader: (2)

I just recently installed a set of Boston SL60 6.5" componets. My amp is a JL 300/4, with the front two channels running the componets and the rear channel running 1 10" Boston sub(the sq of the sub is amazing BTW).

The componets sound okay at low volumes, but at 3/4 volume they seriously distort. Both the left and right channels BTW. They are so bad that I managed to get the cheap pair of Pioneer 6.5" coaxials connected to the headunit to play cleaner and louder, when faded to the rear.

When I tried to set the input sensitivity on the amp using a voltmeter, the maximum reading I recieved was 8 volts. The **** should have been set to a reading of 17.6 volts. Right now the **** for input sensitivity is set at a little less than 1/2, to prevent distortion. The cutoff for the high pass filter is set at 110 Hz, to try and prevent distortion.

Any thoughts on what the problem could be? Do I have a dud amp or a dud set of speakers?

shouldaboughttheZ

iTrader: (8)

Have you checked the polarity of the speakers, meaning making sure they are hooked up right?

AronZ28

iTrader: (2)

I'll check that today, it was pretty late last night and I had about enough of fiddling with it.

EDIT: When I was adjusting the input sensitivity(with all the speakers unhooked), something was wrong because the voltage would only go up to 8V, where it was supposed to be set at 17.2 V. I might be getting a bad signal from the head unit(its a Pioneer, the one with the fancy organic display and too many features) I'll check all my wires and make sure they aren't loose or frayed too.

GPz1100

What are you playing when doing the voltage measurement... Are you using a sine wave?

Does your meter display true rms?

You should be using a sine wave.. 1Khz sine wave would be a good starting point.

AronZ28

iTrader: (2)

That's what I'm using, as specified in the JL manual. My rear speakers were hooked up to the head unit when I did the test with the sine wave, does that matter?

AronZ28

iTrader: (2)

I am almost 100% certain the problem is the head unit. I think the signal coming from it is not clean, giving me distortion. I turned off all of the equalizers in the head unit, and set it up according to the directions in my JL amp instructions.

I triple checked all my wiring, its all straight.

The voltage reading I am getting for the front speaker input sensitivity is way low, the maximum reading I got today was 9.2 volts(should read 17.6 volts, with the **** signifcantly below maximum). I tried a different set of RCA cords with the same results.

I managed to get the correct input sensitivity reading when I put the subwoofer RCA cord into the same channel on the amp. So I know the amp is fine.

The headunit is a Pioneer DEH-P7600MP, I got it off the clearence rack at Best Buy. I have had it sitting in the box for several months before I installed it, so I do not know how much leverage I have with Best Buy on returning it