Hey,

Ok so my amp stopped working one day randomly when i had the volume barely audible. I replaced my amp (Rockford Fosgate 400s) with a new one today, (Alpine monoblock 350wrms.)

The problem is that the 12inch subs (alpine type s & rockford punch [had to replace one of the rockfords]) only work when the car is really quite and i mean REALLY quite like i have to stick my head in the boot to hear them over the speakers. As soon as i turn the volume up they cut out!

Also since my amp blew ive noticed I have an annoying tone that you can hear when the music isnt cranked and the lights are on. It goes away sometimes randomly and also when i go around left corners (what the?!!?) and has gotten even louder since i put my new amp in.

If i could get my subs working i wouldnt care about the sound when my lights are on but I thought id mention it because it could be related.

Please help me out here! Im desperate:cry:

Thanks in advance,
Matt

maybe yur subs blown ???

nah ive blown a sub before and it still sounded loud but terribly distored, this sounds fine they are just really quite

What about checking your gain controls?

What about checking your gain controls?
^^
also wiring?

You using 2 different subs... what honestly do you expect?

Try disconnecting one and turning the gain right down on your amp, then turn you headunit up to about 85% and slowly turn your gain up. The probably aren't cutting out, just cancelling each other out. If your amp doesn't go into protection mode when you turn it up then it is cancellation.

i used the same 2 different subs fine with my old amp and it sounded awesome, they are failry similar statisticly.

I have checked my wiring from my amp to my subbox and insinde the subbox and everything is fine. I might try hooking a single sub up or try the amp on my mates 2 12's and see what happens.

Try swapping the + and - around on one of the subs. Solved my problem :).

What about checking your gain controls?

yep i tried them on all different settings as well as the bass eq and low pass filter

Try swapping the + and - around on one of the subs. Solved my problem :).

I tried switching the + and - wires around on my amp and it was exactly the same

check your ground wire.. might not have enough contact to the car.

thats usually the case for amps cutting out

I tried switching the + and - wires around on my amp and it was exactly the same
Did you only try it on one sub or both?
I found that with my setup, 1 sub had to be wired + to + and - to -, and the other sub - to + and + to -. Though now it doesn't matter, so maybe i just had dodge wiring on my old setup lol.

well my subs have their wiring soldered inside the box so im sure they are correct, they worked fine with the old amp. that is why i tried swaping the wires from the amp (monoblock) to the box around and like i said it didnt seem to make a difference. :confused:

You could have one coil shorted but not burnt so there would be no scraping noise but they would be very quiet and the amp would still cut out way early.

check your ground wire.. might not have enough contact to the car.

thats usually the case for amps cutting out

Checked it and it is fine.

For what its worth i whacked a voltmeter on the battery and earth leading into the amp and it was on 12.6v so that would indicate my earth is fine, right?

Hey Meh you were right! my sub was blown just like Razorjack suggested. Last time i blew a sub it was a really insane noise and the amp didnt cut out so i just assumed my amp died!

So basically i bought a new amp for no reason but im getting store credit to buy a new sub and some speakers so it actually worked out in my favour despite all the ****ing around.:D

Thanks so much everybody! You guys rock!!:bowrofl: