Amp buzzing my front and rear speakers - Page 3

TwoFour · Apr 18, 2009, 12:05 PM

I've tried 4 different amps, same thing.

TwoFour · Apr 18, 2009, 12:09 PM

If I just put the key in the noise is faint, when I turn the ignition just before I turn on the car the noise gets louder, then once I turn it on, my car sounds like an RC car. When that happened there was a loud pop that played through all the speakers and then the sub was still going with the music, but my jbl kept going into protect, it was the amp running my 4 speakers inside the car.

TwoFour · Apr 18, 2009, 12:11 PM

so I bought another 4 channel and used my cousins
Old 2 channel mtx. To try them out, well it was still the noise after those were switched into my system.

TwoFour · Apr 18, 2009, 12:13 PM

At first I thought it was just the jbl amp. But now everything I use makes the same buzzing noise. Maybe my ground is bad? Where is safe to drill a hole in the trunk?

TwoFour · Apr 18, 2009, 12:17 PM

my speakers make that noise whenever they are plugged into any amp. That leads me to believe that my main ground is not good, something weird with my power wire, or inline fuse, or speaker wire.

Also something to note, my headunit was not grounded and it was on. The RCAs carry a ground signal, I unplugged them and the headunit turned off. WTF! So weird

P.S. Multiple posts because I'm on my phone!

biggie5252 · Apr 19, 2009, 07:15 PM

If your headunit wasn't ground and was on, then turned off when ou unplugged your RCAs, it's possible that it was grounding through your rcas. All of these amps that you've tried, have they been installed back into where ever they came from? Do they still work in the other vehicles after they came out of yours? I would ground your headunit properly and see if that fixes it. It's possible that you're frying amps as soon as you plug them in and that's why they're all noisy.

Where did you ground

TwoFour · Apr 19, 2009, 08:53 PM

Inside the trunk, on the right side, right by the green plug, I drilled a new hole with a bolt holding my ground terminal down. I also sanded down the paint, so it's bare metal there.

I also got a new headunit, just exchanged mine, see how it acts. I get the same thing. It is grounded in the front, on the bolt right behind where the headunit slides in.

I haven't put these amps in other cars to try them out.

So you're saying maybe once I plug them in it ruins the amps? Why would that be?

TwoFour · Apr 19, 2009, 08:59 PM

This is also weird. I have just one sub, a 10 inch Alpine Type S, nothing too crazy. Well, It is in a small box, and I didn't want the box to move around, so I made my own bracket and I drilled a hole into the cross bars that would be behind the backseats. I bolted the bracket down to there, and mounted the box to my custom bracket. Okay, so here's the weird thing, I was moving stuff around in my trunk, ungrounded the amps (they didn't have RCA's plugged into them) Well, they were still on! with no grounds! I proceed to take off the bracket and the bracket sparks and once I take the bracket off, the amps turn off! Ungrounded! wtf!!!!

Edit: The bracket was held down by a bolt and nut to the crossbar behind the rear seats, and the bracket had two more holes with screws holding it to the sub box.

biggie5252 · Apr 19, 2009, 09:33 PM

Try hooking everything up with that bracket removed. Does that bracket touch the amplifiers in any certain way?

Do you have a multimeter? If so try taking resistance from your power wire to ground, the amp casing to ground, and rca outer ring to ground.

Somewhere, there is an issue of something grounding where it's not supposed to.

TwoFour · Apr 19, 2009, 09:37 PM

The bracket was touching one amplifier, on it's side, because the amp was also mounted to the box, I had it screwed down to the box just below the bracket.

What will the multimeter say when I touch these together? I have one

biggie5252 · Apr 19, 2009, 09:49 PM

Power to ground should be as high as possible, amp casing to ground I believe should also be really high (unless they're touching the bracket when it's bolted in), Rcas to ground depends on the type of signal ground the amp uses.

The amp casing touching ground shouldn't matter, but for some reason it seems that your amps are grounding through the bracket instead of the ground cable. You can also try taking resistance from the ground terminal of your amp to where your ground cable is bolted to the car. Have you looked to see if the where the cable bolts to the car is still intact (the cable didn't pull out of the lug)?

biggie5252 · Apr 19, 2009, 09:55 PM

double post.

TwoFour · Apr 19, 2009, 09:55 PM

Maybe I ruined the RCA's since they were grounded out. ?????

Yimke · Apr 19, 2009, 10:04 PM

Ok I think I got to this thread just in time before anything else goes wrong.

Start at your source, get a Digital Multi-meter and test the RCA connection since the RCA's are run seperate of the power wires. Also move your RCA wires away from anything that outputs EMF waves. ECU, high powered wires.

1. Test the RCA's by putting the negtive end of the DMM on the outside edge of the metal of the rca plug. Put the red end on the inner RCA plug on the tip. Now turn the deck up and you should see an increase in A/C voltage. It should go from like around .8 volts A/C to 2-5volts A/C depending on the output of the deck. Check ALL rca plugs. If they are all normal, good.

2. I don't know wtf you guys were arguing about distribution blocks, but ya.... fused distribution blocks are junk. As said before add up the amperage of each amp that it pulls and put a fuse that equals both of those and put it up by the battery. If you exceed the maximum amount of amps that the 4ga can take (usually 100A) Then you need bigger wire or leave it at 100A. You might not even pop it. Then use a non-fused distribution block to split the power to each amp. Preferably in the middle of the two amps. Same with the grounds. Connect both grounds to a d-block and connect the other end to a "PAINT CLEANED" metal surface and screw it in with 3 self-tapping stainless steel screws. If you don't clean the surface of the ground, you don't have a true ground and the amp can use the RCA's as a ground and ruin them.

3. If you still have alternator whine buy a new set of rca's and try to replace one at a time. If the noise goes away when you replace a set... you've found your culprit. It could maybe be multiple RCA's I have no idea. Just test them all.

4. If you still have noise, it might be the point where you might want to post pics so we can see what is going on.

biggie5252 · Apr 19, 2009, 10:05 PM

I doubt you actually ruined the cables. It would have either been the amp, or headunit. I'm pretty sure it's not the headunit since you say the noise is still there when you unplug the rca cables.

I'm starting to think more and more that there's something wrong with your ground wire.