Got everything put in finally. 2 Orion HCCA 225s, and an Orion HCCA 250 on subs, audiocontrol 4.1 and 3 way cross over, six 6" mids, six tweets, two 12 subs, two extra blue tops, autotronics rebulit alternator. all mid to high end wire, rca's, ect. Tried real hard to run pwer away from RCAs and speaker wires. <BR> <BR>Got alternator noise. Kinda a whine, crakling noise that modulates with the accelerator. Doesn't get loader, but changes it's tone. It's there at idle or WOT, nothing when the engines shut off. <BR> <BR> I'm not a pro, but have installed numerous stereo in boats and cars/trucks. This is new to me, I have never had this problem in other systems, so I have no idea where to start. Do i need to go through the wiring and reroute things, or is their a filter or something i can use?

Ther are alot fo differnt places you can pick up "noise". Could be from yoru RCA's? Could also be from your grounds? On my old boat I had to disconnect the power/ground to the radio harness and wire it directly to the battery (compliments of Mikeski). Whle alot of people use them on here, I'm not a big fan of any eq....IMO they are noise makers. Unfortunately your best bet might be to try and trace the problem back starting at the radio. Is the noise from all speakers? Just one set?

Make sure your grounds are solid and make sure your RCA and you power\ground doesn't run next to each other. <BR> <BR>There is a noise filter you can get for the RCA cables and that usually will solve your problem.

Noise from all the tweets, not sure but I don't think I hear anything from the mids and subs. The stock head unit/clarion amp, and cheap coaxels had no noise. The stock Clarion head unit was left in the new system with it's exsisting wiring. The RCAs are high end shielded for all connections. I usually don't use an EQ, but the stock radio location is away from the driver, and I wanted a little more adjustablity from the driver position than the remote provided. <BR> <BR> All power and ground for the amps run directly to the battery. The head unit has the stock wiring, the EQ I used the wiring for the stock amp, and the crossover I used an open fuse location in the stock wiring. So those three are wired into the boats factory wiring. <BR> <BR>

I'm gonna start with the grounds. The only place power and RCAs are close are at the amp.

You mentioned the noise is coming from the tweeters. I don’t know how to stop this , but on some amps if you turn the gains up to high you’ll get allot of noise coming thru, only at high frequencies. I had a huge problem with this in the NVS (only out of the horns) It’s sounds basic but remember, those noises could have always been there, but when you put an amp or bigger amp to them it will just amplify those noises, to an audible level. I’m sure there’s a technical explanation somewhere out there.

One of the biggest problems we run into is bad power and ground at the head unit.

Make sure you tie all the grounds for the head unit, eq and amps to the same groundpoint. You probably have ground loops from the new powered devices that are tied together via RCA's. You could try one of those ground loop isolators that plug inline with your rca's but they strip a little tone. It's better than whine, though. You could plug it into the output of each device one at a time to isolate which one was introducing the noise, then work on that part to get rid of the noise. <BR> <BR>If your RCA cables have a drain wire, connect it at one end ONLY. The source end. <BR> <BR>As Adam mentioned, it may just be that you never noticed it before and you are running higher gain/freq response components now. If so, you might be able to use more suppression right at your alternator. That wouldn't affect the sound.