NemeGuero

iTrader: (15)

I ran the RCA cables along the driver side of my 2002gs300 and the power cable along the passenger side but I still hear the "whine" noise produced from RCA signal distortion..

Along with the RCAs, I ran the GPS antenna wire, the reverse cam signal wire, and amp turn on wire.. could these things be affecting the RCA signal?

Where could I be picking up the noise from?

Is there a better way to route the RCAs? Down the center console?

rgarjr

iTrader: (1)

could be your ground spot. I have all my cables running on the passenger side and I hardly get any ground loop noise.

Which head unit u installing?

NemeGuero

iTrader: (15)

Your RCAs are on the SAME side as your power cable?

I installed the flyaudio d7500 but the cables are for my amplifier.

I used a bolt behind the rear seats to ground to. I used a wire brush to clean away the paint on the metal.

Big Mack

iTrader: (1)

Neme,

Check the entire path of the RCAs to ensure that they are not crossing any motors or other high draw items in the system. It is entirely possible to run power and RCA cables down the same side and wrapped together and not get noise in a system provided you are using a quality set of twisted pair RCAs.

My first suggestion is not to change the ground but to check and see if the noise is present in the amp without signal. Remove the RCAs from it, and if you still have noise, it's the amp. If not, it's upstream. Unplug them from the deck. If the noise floor is lowered significantly, it could be creeping in the cables. If it disappears entirely, you may have a problem with the ground on the deck.

Keep us posted.

Big Mack

NemeGuero

iTrader: (15)

The majority of the feedback is coming from the subwoofer only.. not any of the door speakers.

I can pretty much gaurantee that my RCA's are not that great of quality. I think I'm using the soundquest 8ga install kit?
http://www.amazon.com/SoundQuest-SQK.../dp/B001F6ITRE

How will I know if they're crossing any motors or high draw items? I just ran them along the door sills into the trunk. They do go up and across just under the steering column to the back of the HU though.

I'll unplug the RCAs and see if it still makes noise though.

NemeGuero

iTrader: (15)

So I unplugged the RCAs and I can still hear the distortion whine.

It is really really faint with the RCA's disconnected but it is about 3 times as loud with the RCA's plugged in.

Does that mean the ground wire to the HU isn't as good as it should be? I used the ground wire from the factory harness...

Big Mack

iTrader: (1)

If you still hear it but it's 3 times louder, it's being transmitted through the RCAs. If you ran them across the way you said above, that could be a big problem. Can you unplug them from the deck and leave them in the amp? This would give more insight - they'll pick up the noise if it's from the column. I don't recommend the factory harness ground, either. Try a bolt in the dash, preferably not anodized and with paint/coatings underneath removed. It's a tight area, but a Dremel or nail file work well for this task.

Those RCAs should be okay, since they're twisted pair. I don't like the idea of "copper clad," but they should be okay for this task.

Big Mack

tneig002

It really sounds like a ground loop to me, although it's likely that a small amount of that noise is coming from the turn-on wire/GPS antenna as well. I wouldn't move those as a first solution though.

A good quick test is to take a few small pieces of wire and ground them to the RCA shields (do the channels concurrently). If that eliminates most of the noise, you can either use this rig system permanently or actually install a ground loop isolator.

Big Mack

iTrader: (1)

Uh, if it's a ground loop, how would you fathom that it comes in on a positive wire such as the remote turn on? GPS antenna? Nothing to do with this problem whatsoever.

The zero cost method of removing the RCAs from the amp is a better test, which is why I suggested it. We're not 100% sure the deck is quiet, but the RCAs are picking up noise, which could be ground related (doubtful), or (most likely) they are picking up noise from the column as they pass by. If the check with RCAs in the amp and out of the deck yields similar results, then grounding the RCAs will do virtually nothing but create a bigger ground loop issue.

Big Mack

NemeGuero

iTrader: (15)

Hey Big Mack,
So I unplugged the RCAs from the HU and left them in the amp and the noise is still there and still as loud (with some crackling even).

I'm guessing this means that I have to re-route my RCA cables, right? Can you recommend where to route them to have the cleanest signal? Down the center console? (2GS)

I then unplugged the RCA's from the amp too and could still faintly hear the whine.. Is there a way to tell if thats because of the poor ground on the HU or if its just a noise that the car is making? (besides obviously giving it a better ground)

Appreciate the help.
Evan

Big Mack

iTrader: (1)

It's definitely picking up noise along the path. I would move them to the other side. I highly doubt you'll pick up noise on the power cable alone, but string it through temporarily and check everything prior to buttoning it up.

This is pretty normal, but could be completely avoided if you try other grounds for the amp. Keep in mind that the amp is doing it's job - no signal is being presented to the amp, and if the ground circuit isn't isolated well, it may never completely disappear. Unfortunately, some of the lesser designs in amps today are simply designed this way. They keep the damping down because it keeps the total cost lower. Once the amp has a signal, it's a moot point provided everything upstream works well.

The HU has nothing to do with the amp having whine if it's not connected to the amp.

Glad to help, mang.

Big Mack

NemeGuero

iTrader: (15)

I grounded the amp to a pre-existing ground location behind the seats. Thats not good enough for the amp? And It could still be coming from the amp without the RCA's connected? I thought that it meant it was the HU acting up?

And I thought rule #1 of audio install was to route RCAs completely seperate from the Power cable?

PS. I have a LEGIT amp.. Precision Power baby..

Big Mack

iTrader: (1)

It might not be good enough. Have you checked it with a meter? If you're not getting an almost idential voltage reading at that location and your battery with the engine on, it's not enough. Make sure you've got the same size wires and all that good stuff (I'm sure the kit was adequate). Yes, it could be the amp itself. If you disconnected the RCAs, it wasn't getting any outside signal, so there is either a bad ground loop problem, poor isolation, or the amp is not functioning correctly.

How would the head unit be sending a defective signal to the amp if it's not connected. Amps don't read signal off the remote lead, only the RCAs. If they are not connected, the amp is simply amplifying whatever is present in the signal chain between the inputs and amplifier stage.

Used to be. With twisted pair, it's not totally required due to their inherent noise rejection. If you get noise due to the routing together, though, separating the cables is a good idea. In your case, you got noise because the driver's side has an inherently noisy path around motors and solenoids.

Old skool PPI, or newer post-DEI? They are VASTLY different animals.

Big Mack

NemeGuero

iTrader: (15)

old school.

what I mean is that I disconnected the amp 100%.. Removed the rcas and the power connectors and I can still hear the whine. That shouldn't be the amp should it? Maybe it's just the car and I'm going crazy..

I tested it without the car on and got a strong 12.89v but I'll double check with the engine turned over.

Big Mack

iTrader: (1)

Nice.

If the amp is completely disconnected, it shouldn't be radiating any noise into the sub. Not sure what is going on there. I'll go with your diagnosis of going crazy.

Yes, check that. It should be almost identical if it's a solid ground.

Big Mack