So i finished installin my HU, speaks, amps, cap, sub, and all the goodies. Well when i cranked up my car to listen to it, i hear a slight whistling type sound... kinda like a turbo or supercharger spoolin up. what causes this sound and how do i fix it?

 

alternator/engine noise..... usually a bad ground causes it........ that noise scares the crap out of me, its sometimes a PITA to fix....

 

what is a good grounded point for my system?

 

Heres a recent thread people were discussing this http://forums.maxima.org/showthread.php?t=402664

if no conclusions there try doing a search with the google seach engine..... i personally am installing my system this weekend and im going too drill a hole 5/8 i think, in the trunk spare tire well, put a stainless steel bolt/washer through and put another washer O ring ground and put the nut and tightin it, hopefully it will work....and besure too sand the area good, to bare metal, on both sides.... hopefully it will work no problems, where do u have your current ground at?

 

noise filter from wal-mart. its about $15 and it worked for me. You just plug your rca wires into one side and plug it into the amp and you are done

 

does it change pitch with your rpm's? if so, it's alternator noise. double check all your grounds, maybe find a better ground point.

 

Use a supressor as a last resort, try to isolate where the noise is coming from first, and work to fix the problem. It is a pain in the a$$, but usually noise suppressors don't work, or at least to any real degree [90MAXGMG is one of few people who it has worked for].

Of course, this all assumes you've set your gains well, and don't have them so high that it's just the noise floor you're hearing.

dh

[Hey, I graduated to Maxima Enthusiast --- that was quick].

 

I agree with danhaman.
This is probably the easiest to check. Be SURE/POSITIVE that you have your gains set correctly.
If your gains are indeed set correctly, the next step is to look for a better ground point (the ideal is clean bare metal). Also make sure that your signal wires are completely separated from your power lines.
Any add-on suppressor should be absolute last resort.

CFC

 

OK, so i know it is alternator whine, because it gets louder as i rev the engine. So i regrounded my wires to the strut mount (seeing that most people do and it is a good place). I scraped the paint off with some steel wool, not all the paint but most of it. I lowered my gain on my amp a lil bit. But there is still a slight hint of whistling going on... what could it be?

 

Well... it's the alternator.
You shouldn't just lower the gain "a lil bit" you need to adjust it properly. That can either mean raising it or lowering it.

CFC

 

Strut mount are typically a bad idea...too much friction. Seatbelt bolts are also typically not very reliable as there usually a bit of locktite on them.

Where is the HU grounded?

 

This is not true, it doesnt matter which side or where your signals are. A very common misconception.

 

well yea, i toned down my gain some on the amp. My HU is grounded to the stock ground wire on the stock harness.

Where should i ground my amp and HU?

 

The wire in the factory harness is non existant and serves no purpose. Ground the HU to metal. Theres two bolts below and to the left and right of the HU. You can use either of those.

 

We'll have to agree to disagree. I know the effects of improperly shielded cables next to power cables... it's very true.

CFC

 

ima mess around with the gain some more tomorrow...but how does the HU ground play a role in all this... isnt it just the power and ground wires... like the main cables supplying power??