I just came back from my audio installer, Sound Advice in Mission Viejo (SoCal). I had the following installed:
jl 10w6 in 4080 box
elemental designs nine.1 and nine.4 amps
elemental designs 6500 components

Everything went well except for this one big problem. There's a very noticeable and annoying high pitched whirring noise coming from what seems like all my speakers. Actually, there are TWO different whirring noises I hear. First, there is a louder, more constant whirring that starts as soon as I have the car "on" (not yet started). The noise gets louder once the car is started. The second noise is a more faint whirring that is harder to notice but increases in loudness as a get on the throttle. So when I accelerate, the faint whirring gets louder and fades away again when I let off the gas. The louder, constant whirring is on all the time. I went to Sound Advice because they do G35s regularly and the installer told me he's never had this problem before. He told me he tried hooking up other amps they had in the shop to see if my amps were the problem but he said the same noise was being produced. So he thinks it might be the headunit that's causing this noise. Here are two video clips I took. You should be able to hear the exhaust noise plus the whirring noise.

http://media.putfile.com/MVI_091290
http://media.putfile.com/MVI_0910

Also.. I spoke to Ed Lin, who owns an 03 sedan about this. He had his audio system done at sound advice as well and he said he also experienced the faint whirring problem, but not the louder one. He told me the owner at sound advice was able to fix his problem by installing another part, a "noise canceller" or something.. Ed wasn't sure what it was called. So I guess I'll give them a call and see if I can get that thing put in and see where it goes from there. I really hope I won't be forced into getting an aftermarket headunit b/c of this crap. I really wanted to keep my stock head unit since it's 6 CD plus mp3 and an aftermarket one with similar features will cost me a lot more than I want to spend since I'll probably be doing double din with an aftermarket nav if I'm forced to go that route. My plan is to get that noise cancellation part installed and if the problem still exists, I'm planning to swap 05 headunits with someone to see if it's my headunit in particular and then as a last resort, test an aftermarket headunit to see if that gets rid of the noise.

So does anyone have any ideas as to why this might be happening? Any help would be VERY VERY much appreciated. Thanks.

 

you got a LOC?. it might be your wirings. I still have this little hmmmm noise coming from my headunit..but nothing from speakers.
My setups are: 4080/JL10w6v2d4,CDT's components,PG xenon amps.
i'll post my setups soon....gotta wash the car cause kinda dirty right now to post -:P.

 

I too am having engine/alternator noise on my speakers. I get this even when the radio is off. I am going to make sure my RCA input wires are no where near my power wire (I thought I moved them away from it but who knows, crap moves in cars).

It could also be because your gains are too high and are enhancing what would normally be unnoticeable engine noise. Unfortunately this is not the case for me.

If moving my RCAs away from the power wire does not solve the problem, I will most likely invest in a noise canceller, I think they are also called ground loop isolators.... maybe they aren't the same thing.

Someone once told me this noise can have something to do with grounding, but I cannot confirm exactly what he was talking about or if it was even true.

For reference, I do not use a LOC.

 

not to get off subject...can you post some pics...

 

My installer used a ground loop isolator. There is no noise. There is a description of the install with pics in this forum.

Audio Upgrade in 2003.5 G35 Sedan

SQ is awesome.

 

Actually, I will throw this in: Even WITHOUT a ground loop isolator, geeman49's car had no noise. None. Zip. We used the GLIs to show the Bose HU a better load, since it seemed to distort at higher volumes a little bit without it (around 22 out of 31), and we only used it after a good bit of experimenting. We got it up to 29-30 without the HU distorting with the GLIs in place, and it was a bit quieter at the same setting, but it sounded better.

Elemental amps do not have balanced inputs. They are referenced to chassis ground on the outer ring of the RCA. As such, they don't take balanced inputs very well. Diamond, Rockford, and some others have this kind of issue too. I would be curious which amps they tried in place of the eDs.

What I would use is a Soundgate LOCPREA (if you are using F and R outputs from the CD, use two of these). Soundgate might say to put it at the radio - balderdash. It works fine at the OEM amp location. Just keep it away from the amp's main power wire.

A GLI might work just fine... but I'd use one of these.

By the way, in a sense, the headunit is part of the noise, BUT it's not injecting the noise into the system - it's produced by the combination of the amps and the HU. Installers love to blame the HU, because it is easier to install systems with an afetermarket HU - you don't need to know as much about electricity and audio : ) But we can do it as an industry, never fear.

My shop specializes in OEM HU interface. If you like, I will be happy to talk with the installer about the project and lend support and advice. Email G35support at avincar dot com and I will send you my phone number (or the store number's on the web site).

 

achen - I'm sure you paid some big bucks for the Sound Advice system & install, take it back and have them fix the problem. You're not satisfied with the system.

 

Thanks for the reply guys.

el_duderino: I sent you an email.

 

tell them to reground the wires. or ground w/e it is you ground. i forgot but it deals with that. basically it sounds like ur car has a turbo and when u let off the gas it stops. then most definaty its that
-Tim

 

The guy told me that was one of the first things he tried. He tried different grounding points also and the problem is still there. I don't think it matters but I have gordgee's grounding gear installed as well.

 

JUst talked to Brian. They have done everything that the standard installation would need, and tried a good deal more. The old "check your ground" ain't it on this one.

It is definitely an unusual problem and I am pretty confident that they have done everything correctly on their OEM interface. YOu might try fading the HU all the way F and R and seeing if the noise stops when you reach the limits, or L and R and checking the same thing.

I've given them a couple of leads... but I think you've got a pretty good team on it at present.

The next thing that I would try is pulling the HU and grabbing the ground wire and running it back to the amp... not something the typical install in that car requires, and probably not something that was quoted, but there you go.

I would also try this amp/speaker setup with a Discman or another head unit jerry-rigged in there at the amp end to see if IT has the same issue.

If the HU was GENERATING the noise then you would have heard it before...

Sorry I couldn't help more...

 

hey el_duderino. i just had almost the same setup as achens. But my HU is making this hskkkk sound. I never got that problem but when i got my system installed i hear it. could it be the wirings? on the LOC or anysort. or achen mentioned that it might be engine noise?. but i never heard it until i got my system installed.

 

The Soundgate LOCPREA increases voltage of the head unit signal right?

 

What you have is pretty common when installing a 4 channel amp. It's what we call "Engine Whine". It seldomly has anything to with grounding the wires and can't be fixed with a ground loop isolator. I know just cuz you have components, you want to crack up the highs as much as you can. If you and/or installer can't get rid of the engine whine, turn down the settings of your amp until you barely notice the noise.

I hope your alternator is cranking enough power to supply your battery. Lets us know what happens.

 

What amps are in your system, and where is your amp gain?