I have a friend that is having problems with his amp in his mustang. Its an audio acoustics 4 channel 1200W amp. Anytime he tries to put any sort of a load on the amp, it turns off. We have installed a smaller gauge power wire, relocated the ground, jumped the remote to see if that was bad and still the amp will overload and turn off.

We thought it might just a bad amp. To test this, I installed it in my car and it works perfectly fine. We both have the same subs and cap. The only thing that is different is the box his subs are in and his headunit. Any one have any ideas on what might be causing the problem?

 

why smaller gauge power wire.. bigger=less resistance. is your ground definitely touching metal and not paint??? check the wiring of the subs in the box and check to see if your ground is straight.. you could have the subs wired parallel when they should be series or vice versa. use this page for reference on wiring

http://mobile.jlaudio.com/support_pages.php?page_id=145

most amps are 4 & 2 ohm. some you can get to 1 ohm and i have yet to see many go below that.

also some amps dont like 8v preouts.

 

Is he using the 4 chan for his subs?

If its actually going to his door speakers he might have a speaker wire pinched and is shorting out to ground. If its to his sub could be too low of a ohm load on it. Lower end amps sometimes cant even do 2ohm. 8v preout is unlikely most aftermarket hu's only have a 2v maybe 4v.

 

I would say check his wiring first, make sure nothing is reversed then test your ground with a voltmeter and make sure it's a real good one. If that checks out then it could be the HU I guess. My money's on wiring issue somewhere in the circuit.

 

He is running his subs off of it right now and plans on hooking in his rear 6x9s as well. The headunit preout voltage is 2 volts and the ohms on the box is only reading about 1.5 ohm.

 

sounds like its the subs 1.5ohm is way too low for a 4 channel. Save some money and go with a mono.

 

^^^ i agree

for the most part it should be
mono = sub
2-4 channel = speakers

tell him not to be cheap

 

1.5 probably means one speakers is half blown (they probably are wired for 2 ohms) and as stated above 4 ohms is the lowest you want to go

 

i ran a zx450 4 channel phoenix gold amp to 2 10w3s and it sounded better then the jl 500 mono.
class a vs class d.

 

Class AB's are designed to be sq but less efficient so less power. D's are way more powerful/efficient.

 

Thanks for the info everyone and btw it is a mono amp. I will help him check the wiring in the box to make sure its wired correctly and if so and still getting the low ohm rating then will know for sure one of the subs is blown. It wouldnt surprise me if that was the case either because he cranks it constantly and its always distorted as hell. I tell him to turn it down that it sounds like **** and isnt good for the equipment but he doesnt listen.