buzzing in the stereo

[DevonD]

i have a 4th gen maxima and had an aftermarket cd player put in. now whenever it is turned on there is a buzzing in the rear speakers. can anyone tell me what might be causing this? thanks!

[lightsout]

take a look into CAPACITORS @ http://www.crutchfield.com (i think they will have them)

how old is the HU (Head Unit)??

O, and their is this thing that looks like a tube that your wires go through to keep out the engine noise through the battery cables(that's what your hearing), but i cant for the life of me remember what it's called...

i'll think of it

[jltibbs]

'Alternator whine' or 'ground noise' is what it is called. It is actually caused from bad grounding.

[lightsout]

aaahh....that's it!!

[blazncypher]

if you have just an aftermarket cd player and no amps then you arent getting engine noise, unless you have a old p.o.s. was your stereo professionally installed? if so take it back the probably hooked it up wrong.

[davskins97]

Does the noise change pitch when you rev up the engine? If so, you are hearing engine noise or alternator whine.

A complete rundown on what your entire system consists of would be helpful.

Specifically, how are the rear speakers powered?

Did you actually ground the stereo or is it grounded by the radio antenna?

[DevonD]

okay.. well i will try to answer all your questions to the best of my ability.. so the head unit is less than a year old and is a JVC. The speakers are the stock BOSE speakers and thats pretty much it. It was proffesionaly installed but it was done 12 hours away from where i live. And yes the noise gets a higher pitch as the rpms go up. I think i covered everything..Thanks again for whatever insight you guys have!

[aubergine]

This is quite interesting to me too, as I'm having issues with the sound system in the car I just bought. zerothread/327882 The rear speakers are blown and there is also a buzzing sometimes, although I'd thought that was from the way the system works (one of those one's where the radio must be tuned in to pick up the CD player.)

I think if I had the money (after buying the car!) to just have the whole sound system replaced I'd do that. Most of what's in mine seems to be aftermarket already.

[davskins97]

Well, I'm going to work under the assumption that this is something new. Blown speakers definitely make buzzy noises. Listen to the rears with the engine off and see if the sound right. Try louder volumes and music with some decent bass in it. If the rears sound right (not blown) with the engine off, then my best advice would be to drive the 12 hours and get the hu or wiring fixed under warranty. Because you had it professionally installed this isn't your problem (unless you blew the speakers). Since it's only the rears I would guess that there is something wrong with the hu. I'm also going to work under the assumption that it's not worth the drive. So here's the second best advice.

Alternator whine most often comes through the ground wire(s).Pull out the hu.See if it is grounded. Since it was professionally installed, it certainly should be. It should be a black wire with a ring terminal attached to something metal inside the dash. Make sure it is securely connected. Make sure it isn't rusted. All of these can reduce the effectiveness of the ground. The condition of the ground may have changed introducing the noise.Disconnect the antenna plug. See if the noise goes away. The antenna can also be a ground for the hu.Plug the antenna back in and disconnect the black wire ground. Is the noise still there?Check the conditions of the wire terminations for the rear speakers. This is a long shot. You could disconnect the fronts and rears (be sure to mark the wires before you do this) and swap the fronts and rears to see if the noise moves to the front speakers. This would indicate there is nothing with the speakers.

That's about all I got. Hope this helps.

[DevonD]

ok so today i checked it out. the buzz is gone with the engine off and with the engine on but the stereo off the buzz also goes away. i removed the head unit and swapped the wires around and it seems no matter what i do the buzz stays in the rear speakers and i listened closely to both of the rear speakers with the engine off and they both sound perfect. so from what you have all said im looking for a ground issue right? where are the alternator and antena grounds located? i looked quickly through my haynes manual but couldnt fand anything.

[davskins97]

Which wires on the head unit did you swap around?Here is a wiring diagram (make sure you pick the correct one) for the 4th gen stereos.Did they bypass the bose amps and power the speakers with the headunit or did they adapt the headunit to work with the amps?

Alternator whineThe ground wire I was referring to is the one coming out of the headunit. It is black and you should be able to follow it to a bare metal grounding point. The other effective ground is the antenna plug. The antenna will ground the hu also (typically). So between those 2 "grounds" could be your issue. Alternator whine is not going to be corrected by messing with the actual alternator wires.

[blazncypher]

they most likely used a crappy wire harness and thats why your are getting engine noise. try replacing your wire harness or bypass the harness and wire it up from the JVC directly to your stock harness