Ive got a slight issue and I hope someone can help me out. so about 7 months ago i put in a system into my jimmy. its nothing special. a 700 watt amp and a 12 inch subwoofer. well just recently ive been hearing noises from the sub. it doesnt get louder or softer with the volume or anything. its like a clicking or scratching sound almost. so i figured maybe a wire is broken and possibly touching metal? well i then unplugged my RCAs from the amp, just to see what would happen, and the noise was still there. what could it be? the noise comes from the sub and its annoying and id like to fix it. im thinking its something stupid and easy because it recently started and its never done it before.
Thanks in advance guys!

 

Have you checked the ground point for your amp?

 

^^^ Yes, check everything. The ground point, power cable etc. for any connection issues. Be certain they're clean and solid.

However, I'm afraid it's probably not going to solve your problem. Bad connections usually only show issues when the amp is drawing power. The high resistance from the bad connection causes voltage drops and other such issues. If you're hearing noise from the sub when the RCA's are disconnected then there is something wrong in the circuitry of the amp. With nothing connected to the RCA's the amp has nothing to amplify, it's sitting idle and not doing any work. Any noise coming from the outputs of the amp is from something inside the amp.

Hate to tell you that, I hate giving people bad news. You're likely going to need to replace it very soon before it does damage to your subwoofer.

 

Very good point, i did not think of that,
and a lot of times when its a ground problem, when you are listening to music, there will be a random "pop" or hard thump, good indication of a ground or power issue cutting out and back up.

 

Use a digital multimeter and check the ohm load on the woofer. If all else fails, pull the speaker out and see if something came unhooked??

 

Thanks guys, ill go through and check everything. it may be that i only pulled out one of the RCAs so it could have been getting signal from the head unit still possibly. ill go through and check it all out before i consider replacing it. thanks alot guys!

 

It has been 15+ years since I have had or worked on large stereo systems so forgive me if my info is out dated. Does the amp have its own positive and negitive leads to the battery, with an in line fuse? Back in the day we had to get an (used to be called) noise filter that installed in the positive loop to the amp to take out the noise from the alternator. When I had two 1000w amps I had to wire them up seperatly with a noise filter on both to eliminate the noise from high out put alternator that I had to get to run them.

Like I said it has been forever since I have messed with one of these, and for all I know the filters are built into the amps now. Does it do this with your engine off? If it does it does sound like the amp is going bad. I hope you get it sorted out.

 

I wouldn't recommend running a ground wire from the battery to the amp, that'll cause noise. It's best to keep your ground wire less than 3 feet, 1 foot or so is optimal, but, I realize sometimes, that isn't possible. Just try to keep the ground as short as possible. If it's not too difficult, maybe try another head unit or amp, just to rule out possible causes.

 

If you run the power wires on the opposite side of the car from the RCA wires it will eliminate noise.
As for leaving one rca plugged in, it would have still gotten a signal

 

Well i cleaned up the positive battery terminal which seemed to have helped but it still does it every now and then. maybe its the amp...and about the noise filter, maybe those are built in. i have never thought about that before but it just struck me that it does do it with the engine off. also i do not have the ground running to the battery its about 2 feet from the amp if that. Maybe ill look into a new one. is there anything that i did to ruin it? or make it produce noise like that? if so let me know because if i get another i dont want this to happen again haha. thanks for the replies everyone