Electric Interference, one for all you audio techies! Options

[danny_t82]

hey guys,

Boot install startin to take shape now with both side installs semi complete. Have been tryin to work out the best configuration to mount the amps/capacitor/fans/wiring/cd changer/neons etc. I think i'm there but before I cut into my nice new constructions to display the amps I wanna know if placing my cd changer behind an amp will create interference an ruin the sound quality? Its a bit of a tight fit to cram it all in there but I think I have a plan.

Interested to hear your wisdom and experience in this situation!

Dan T

PS: On that note will neons cause interference if placed near an amp too?!

[shid]

uhh no, the placement of those two things shouldn't be an issue, and neither will the neons. Unless you're running over 1000W through a line, nothing's gonna change, if you want to be "pro" about it, run your signal and power wires as far away from each other as possible- usually on seperate sidesof the car.

[Makaveddie]

yup, run ur audio signal far from your power lines and you should be fine.

[shid]

but hell, like I said, unless you're running pro level wattage, you'll be fine if they were zip tied together even.

[Pali_playa]

but hell, like I said, unless you're running pro level wattage, you'll be fine if they were zip tied together even.
[right][snapback]242215[/snapback][/right]

i beg to differ man, ive gotten feedback hundereds of times from seein ppl run them on the same side of the car

[shid]

uhm, running the wires close isn't going to cause feedback. it would cause noise if you're using either crappy signal (RCA) or crappy power cables, but it's technically impossible for it to cause feedback.

[mikew04]

if you run your power cables along your RCA's, even if theyre expensive sheilded twisted ones, youre very likely to get noise/interference, or whatever you want to call it... its almost a given.

[shid]

*sigh* no, it's not. Thats really just a very prevelent audio myth. If you're running high power you will get some signal degration

[danny_t82]

Don't get me wrong Shid, I appreciate your advice but I hold a degree in physics myself, and unless the wires are magnetically shielded they will always create an external magnectic field. Wire coatings might be good at insulating electric fields (thank god) but current passing through a nearby parallel wire will always be subject to magnetic force no matter how minimal, this is especially true in the case of DC current as in the power line and I would have thought 12V~20A is enough to create significant interference even though the audio cables are AC. Think I'm gonna run my audio cables down the other side of the car now, I have taken the amps and sub out the boot while I rebuild it but am still running the cd changer and could swear that it does sound crisper than before (although I suspect this might be down to other factors like masses of bass!). I would insert a diagram but I dont know how to get pictures onto my posts

Hope this clears up the confusion, and glad my degree has some use!

Dan

[shid]

Danny, I'm glad you have a degree in physics. What I'm telling you, and telling everyone, is that you have to have a LOT of power running through the wires for it to cause any sort of noticicable difference.

In pyschology, thats called a difference threshold, 600 Ws isn't gonna cause it; 1000W will.

[mikew04]

Exactly what danny t82 said... when you run the lines parallel a current could be introduced to the rca cables, and while this might not be much, its going to an amplifier, which amplifies every part of the signal it recieves.

EDIT: specifically, the current would be introduced to the RCA sheild, and since the amplifier uses this as a reference with the signal wire, difference in voltage could be changed and noise or interference could be introduced.
Ive seen this happen with a 200w amp. my friend was having noise problems, he asked me to look at it, we ran the RCA's down the other side of the car, and he hasnt had problems since.

This post has been edited by mikew04: Feb 5, 2005 - 11:36 AM

[shid]

There are many different possible reasons for the noise that occured from your friends 200W amp, and many things changed when you moved it to the other side of the car- it didn't have to be interference from them being too close together, it could have been a lot of things; power interference with 200W is absurd.

[mikew04]

they were cheap rca's, and im not saying that was the DEFINATE cause, but we did not change anything besides the route of the rca's. the first thing we did was disconnect the rca's and run another pair of rca's through the car to see if it was the problem. noise was gone. ran his rca's on the other side of the car, no more noise. but, if you have sheilded cables, they can pick up noise, and rather easily. its common practice and a good idea to run them seperatly, because it is possible that it could cause noise.