Interference w/ two amps.

GoBlue

Hi, I am installing my stereo, and need help. I have two alpine amps, one mono block and one four channel. When my engine is running and they are both on, I here a terrible buzzing through the speakers. I located the problem, because as soon as I disconnect the ground from the mono block it disappears. Could this be a sign of mediocre distribution blocks, or what? Im almost sure this is a common problem among dual amps, but I dont know what it is. PS: I swapped it from another car and still the same problem.

Ive uploaded pictures to help you better understand my setup, (if they work)

Thanks.

http://i893.photobucket.com/albums/ac136/dirtonthefloor/th_100_4571.jpg?t=1286494376
http://i893.photobucket.com/albums/ac136/dirtonthefloor/th_100_4572.jpg?t=1286494376

kawizx9r

The pics are tiny so I'll ask;

Are the grounds for each amp going to the same place?

You don't have your power cable from battery to amp running on the same side/near your analog cables from your HU right?

I had that same problem in 2 of my cars, and using one spot as a ground for both amps solved the problem. Make sure it's a nice clean contact IE no rust/paint on the metal surface.

-Freddy

Edit: You can ignore me asking if your power cable+rca's are running alongside since you said the buzz goes away when you disconnect one of the grounds. But it's always good to ask anyway

GoBlue

My ground is a 4 gauge mounted to the frame via seat belt bolt, and it goes into a block that Im running 2 8 gauge wires from.

My power wire, and RCAs are as far away from each other as I could get them, so hopefully thats not it.

So... Should I ditch the blocks, (because I have one for the power thats the same size, except it has fuses) and run both grounds to the same place, and can I splice the power wires together or something?

GoBlue

http://i893.photobucket.com/albums/ac136/dirtonthefloor/100_4571.jpg?t=1286495237
http://i893.photobucket.com/albums/ac136/dirtonthefloor/th_100_4572.jpg?t=1286494376

I think these are better.

kawizx9r

You've got a dis block for your ground?

I use one for my power, but I run separate cables for ground.

Here's an older pic, speakers unhooked to the amp so you can easily see the cables. The ground cables go to a bolt where the seats latch on to.

GoBlue

So it sounds like I am not supposed to have this dis block for ground. I thought it was what was supposed to be done, but we will have to see without it.

kawizx9r

GoBlue wrote: »

So it sounds like I am not supposed to have this dis block for ground. I thought it was what was supposed to be done, but we will have to see without it.

Never heard of anyone using one, but I don't see why it would be wrong to use one. Who knows, maybe others have success with it but really I don't see how it'd be wrong too since you're still utilizing the same ground for both amps.

Do you experience buzzing with EITHER amp? Meaning if you disconnect amp 1, amp 2 buzzes and if amp 2 is disconnected, amp 1 buzzes?

Maybe you should try using different ground locations for each amp if you try my method and it doesn't work.

GoBlue

I dont know yet, but Ill give it a shot. This definitely must be a ground thing then, but Just gotta figure it out. Thanks for the info btw.

kawizx9r

GoBlue wrote: »

I dont know yet, but Ill give it a shot. This definitely must be a ground thing then, but Just gotta figure it out. Thanks for the info btw.

Heh anytime! Always here to help

eloplayspolo

There is nothing wrong with using a dist block for the ground as long as the ground itself is done 100% correctly.

kawizx9r

kawizx9r wrote: »

Never heard of anyone using one, but I don't see why it would be wrong to use one.

eloplayspolo wrote: »

There is nothing wrong with using a dist block for the ground as long as the ground itself is done 100% correctly.

Didn't say/imply it was wrong to use one but I'm making an educated guess and saying that there's a ground issue that's creating the buzz he's getting.

Edit: Should've asked about the amps. 8gauge is rather small, and I wouldn't use it for any amp that's pushing over 200wrms.

I personally like to go a gauge bigger than recommended for each of my amps. Power+ground should be the same gauge btw.

exalted512

Actually, I would say using a distribution block for the ground is the correct way to do it. It's good to have a common ground.

I would try scraping off the paint and shooting a couple screws through it thought. Your problem is probably the **** seat belt bolt ground you have.
-Cody

MacLeod

I've always given each amp its own ground keeping each ground wire as short as posible. Always seems to work better and I've yet to have any ground associated noise issues.

TakeTheTime

I have three amps, two of them has dis. blocks for both power and ground,
the two ground cables from the amps are pretty 'long' compared to be ground
cables, and they're 8G - pretty thin. The common cable from the block to the
backseat belt bolt is 4G, and I also have two fans wired to this, so it's all two
2-channel amps and two fans to the same cable, and the subwoofer has it's
own 0G cable to the same spot - I haven't had ANY trouble with this...

Sorry 'bout a very long unnecassary post.
But doesn't your Alpine amps get a
little hot under those backseats?

KaosTsoc

I have always run my grounds to the same spot with out using a dist block. Each time I have done this my self, I pick a place on the car and either put a self tapping screw into the sheet metal, also making sure that I have a sold connect (no paint etc), or I find a random bolt (not the seat belt bolt) remove it grind the area down til I see silver, and put it there. I would do the second option if you dont want to make a hole. Hope this helps.



Thanks.