I need some more advice.
I have a high pitch whine coming out of my speakers. I have been told its a bad ground so I rewired it no avail. My power wire does have alot of other things running off of it as well but can that be the problem?
Are there any noise filters I can buy or something of that sorts?
Im tired of turning up my radio to not hear it!
Keep your powering wire seperate for just your stereo. The more things you plug into that common power wire the higher chance of picking up noise from it. Also run you power wire down the opposite side of the car from the RCA’s. Try and keep everything seperate. If you are using a really cheap set of RCA’s they can pick up noise as well, try and use something that has a spiral core and good shielding. Ohh and yes most times times noise is picked up from bad grounds.
Noise filters are just band aids, I would try and never use them.
Good luck, hope it helps.
CVM07
Just as cvm07 mentioned try keeping your main power cable seperate, as far away from the others, thats whats most likely causing the noise
The most commonly said rule: keep your power wire away from your RCA but i know you’re smarter then that and it wouldn’t be the case. Sound filters are overrated and dont really work as i’ve installed over 10 of those suckers for friends. Try grabbing some performance RCA wires, you dont understand how much of a difference rca wires make. I should have made a before and after sound clip for u when i did my wiring.
D-K
Ill go ahead and seperate my power wire but as for the RCAs I dont have any running. The speakers are hooked up from the deck.
Ill keep you posted.
If thats the case and you are using deck power, then most likely you have a bad ground or using a common gound. The same for the power, you can get noise from either side. I have never used deck power in my s14, seperate amps only and I have never had those probs.
Just recheck the power and ground, if they are wired into other sources then you could pick up noise that way. I am not sure but I don’t think that you can use a filter with deck power.
Good luck,
You’d have to cut the speaker wires and place a hi-level filter inline, if there is even such a thing
all the noise filter’s ive seen are low level signal. maybe farmer knows more about it?
Bah, well I just did some further testing.
I hooked the deck power up to a constant batter signal (key not in ignition) and the noise is gone. Once your turn the key to the radio position the whine pops up. I have tried various wires now, different battery source, different ignition power source and no matter what I do the whine is there when the ignition is on.
Looks like Im going to have to live with this as I dont think its worth my time to trace this down.
What type of deck is it?
Lol, don’t give up you can beat this thing 
I’ve had this problem a number of times with other cars and even a factory stock Nissan in the past.
Since you tried a remote power supply and the whine doesn’t change with your RPM’s then it aint alternator or battery interference…which is very common. You said you tried a hook-up to a second battery and still had the whine right? Just double checking.
Try this.
Grab your Accord and and connect the power leads from your audio system to it’s battery while it’s NOT running. Now you’re getting a clean DC source. If your system doesnt whine while you are revving your 240’s engine then the source of the noise was travelling through your car’s battery power lines. Since you seem to thing that’s not the culprit lets try some other shit.
Now start moving the power cables back to your car one at a time. Amps first, head unit LAST. Chances are it’s the head unit causing the whine. IF so then you need a noise filter like the other guys were saying…aftermaket head units are notorious for whining.
If none of this helps, or the system is still whining while hooked up to the other car (with a constant noise having no change from RPM’s) then you have problem with radiating noise…noise picked via the air in the wiring. From what you’re saying this might be your problem.
Try a couple things. Pull the head unit from the dash as far out as you can away from the dash wiring and see if the sound fades. It could be getting interference from the factory wiring looms. If thats the case than find the factory (or in your case one of the many aftermarket wires…gauges, boost controlers and all that shit) thats the culprit and re-route it. Again, if it’s not the head-unit it could be any component of your audio system…amps, crossovers, bla bla bla. Check all of them if you have the patience.
The only other thing failing all of this would be to check your grounds for a loop. But since you aren’t running any additional power cables or amps I highly doubt thats the problem.