Audio wiring question...

[FlipTrac_511]

Is it bad to run the power line for my amps right along with the speaker and subwoofer wires? In other words, the power line is tucked under the same channel under some plastic trim where the wire harness is, and these wires run next to each other from the front of the cabin all the way to the rear. Does this arrangement become a source of interference/whine?

 

[Craig Childs]

I ran my power wire alongside my speaker lines and I can hear the interference when no music is playing, but other than that it hasn't affected anything else.

 

[FlipTrac_511]

That's exactly what I was afraid of. Thanks Craig. But have you isolated this as the actual reason for your interferance?

 

[Craig Childs]

I installed my new speakers before I had an amp to power them, so nothing was giving them power but the head unit. When it was just that, there was no interference, it didn't start until I ran the power line to the amp. And I don't have anything else to cause the interference that I know of, so yeah I'm sure it's the cause of the interference.

 

[Travis Munday]

Like Craig says, one of the principal rules of audio is to not run power wires next to signal wires or interference will be introduced. You may not hear it when the volume is turned up, or over road noise, but it's still there...that's not really good.



It's better to get longer signal wires then a longer power wire.

 

[FlipTrac_511]

Hah! I have had this whine since I had aftermarket stuff installed (I can also hear CD loading mechanisms). I never figured out what was causing it, but recently I did some audio fine-tuning and managed to get rid of the whine by adjusting gain settings. But it's good to know the possible cause.



How far away do the signal and power wires have to be from each other? Since signal wires are running under the door trim on both sides of the floor, where should I run the power? Move it over the pedals and along the center console and then towards the rear? In this case, will the transmission cause interference?



Thanks!

 

[Craig Childs]

If you really wanted to, you could run the power wires both on one side, and then route the speaker wires on the other, behind or under the dash, and then to the other side. To me, that is way too much work, and good speaker wire isn't exactly cheap. But if you want no interference and have the means to do so, I would run power on one side and signal on the other. My 2 cents.

 

[FlipTrac_511]

Thanks Craig, I'm not down with rearraning that much, which is why I had installers do it for me to begin with.



What about the grounds for the amps? I will be bolting them to the floor. Anything I should be aware of?

 

[Craig Childs]

Yeah, I figured that would be a huge pain, but that's the easiest way I can think of to have as little interference as possible



I just used a washer and a couple of ring terminals and used the bolt that holds down the seat as my ground. It was the easiest thing I could find and my capacitor runs at a steady 12.4 volts or so. I'm sure there are better things to use than that bolt, but it works just fine for me, and my ground cables are black, so it stays hidden pretty well too.



When I screwed down my amp I checked for anything underneath, and all was good. Just be sure to look before you screw it down and you'll be fine

 

[FlipTrac_511]

When I screwed down my amp I checked for anything underneath, and all was good.

Funny you mentioned it, I was mounting an amp the other day and managed to drill right through a harness I didn't know was laying under the rubber flooring. How I got away with just a few ligthly frayed wires (which I taped up) I don't know. This goes down as one of the dumbest things I ever did with the Trac, second to forgetting to close the sunroof when rain was forecasted.

 

[Craig Childs]

Sounds like you were pretty lucky, that would seem like it would turn out pretty bad. Wow, you left the sunroof open? It didn't get too wet did it?

 

[FlipTrac_511]

Yeah I was lucky. As for the sunroof, fortunately I didn't leave it open too long and the leather held up great against moisture. Thanks again for the info.

 

[Brian Hasledalen 2]

I myself have done many custom stereo installs in friends vehicles as well as mine, and i have always ran the battery wire and the remote power on wire down the driver side and all the speaker wires on the passanger side. I have never had a speaker wine or any other noise except for what was playing in the head unit.... Always double check what you are drilling into, because between A/C lines fuel lines or even a gas tank to drill through it could get expensive... Not to mention dangerous...... As far as the ground goes i use a self tapping screw and ground it to the body, this has worked 99% of the time for me. And this might not make sense, but i always ground each unit seperatly.

 

[Tony Tassillo]

The interferance you guys are talking about is most comonly refered to as engine noise. its when you can hear the motor reving through the speakers. The reason this happens is your alternator actually produces AC voltage / current and then routes through a brigde rectifier (four diodes in a diamond shape) that converts it to DC power. if the alternator is not running a high quality bridge rectifier you will experience engine noise or EMI (electro-magnetic Induction).



Running the power wire and low level input down the same side of the vehicle is a touchy subject to installers and electrical engineers. is you use cables which use twisted shielded pair. this significantly reduces EMI.



Another reason for engine noise is a Ground loop. this is normally caused when one of the components in the system has a bad or poor ground. this is not only limited to the black wire on the radio or the ground from the amp. if an RCA input or output has a broken or poor ground you will experience noise as well. this is simply tested by taking what you know to be a strong ground and touching it to the shield or negative of the RCA. if you have a bad ground on your source unit you will experience tracking noise as well as some engine noise. this can be fixed by grounding out the shield or negative of the RCA.



Also be sure your ground for your after market amp is solid and not secured to a poor ground. good places for ground wires are



shock towers

seat mounts

seatbelt mounts

ect...



thick solid metal that requires a self tapping screw is recomended. also cleaning the surface to bare metal is required for a good ground.



Pioneer had a problem a couple years ago when they switched from MOSFET transistors to J-FET transtsitors. they had RCA grounding issues right out the plastic. They have since switched back to protect thier reputation.





If anyone has any questions feel free to email me and ill see what i can do to help.



Tony T.

 

[FlipTrac_511]

Thanks Brian, MPTony. I actually finished my audio project today...finally. It shouldn't have taken as long as it did considering I was just relocating an amp and then moving wires around, but it was foreign territory so I took my time.



Both amps are grounded independently on the floor, where it's secured by a self-tapping screw. I chose a spot where I could see where the screw would be going through underneath, plus I took the paint off around the contact area.



It's nice to finally have the jack kit relocated to its original spot behind the compartment, as well as have both compartment panels reinstalled (which the audio installers had to leave out previously).



Thanks again. Time to fine tune...

 

[Dingo]

My amp power wire is actually running inside the frame rail on the left. It enters the cab in the back underneath the factory sub.