I'll be installing a CD changer (actually a hard drive unit, but it installs like a CD changer) very soon. This involves removing the head unit, knee pad and carpet clips and running the changer cable back along the driver's side of the center console.

I'll probably also install rear speakers within a couple of months. I'd like to avoid having to disassemble all of that stuff again. Is it reasonable to plug in Lucid's rear speaker harness and run speaker wire back toward the trunk now, and just wrap the ends until I get around to the rear speakers? Is there any risk or operational issue I should be aware of in operating without rear speakers hooked up?

Also, is it OK to run the rear speaker wires parallel and adjacent to each other and the "CD" wire or should they be separated to avoid interference?

Thanks for your help!

 

If you keep them wrapped you're OK to prerun them. I always try to separate any wires that carry a low current signal (CD wire) and high current (speaker) due to potential interference. I do it all of the time with only the ocassional issue popping up, but just try to avoid it whenever possible. If you're running power wires along the same route, I would separate power into one bundle and the speaker/CD wires into another bundle.

 

I preran the rear speaker wires for the rear speakers when I installed the new head unit, no problem at all, I did forget to install power wires for the transceiver and the antenna wire for it but then I may never install the transceiver. I have been installing power wires and low level wires in the same bundle for years with no problems, low level wires may have to be shielded however. Usually they come shielded.
Andy

 

[QUOTE]Originally posted by Andy Kirk
[B]I preran the rear speaker wires for

 

These are very good suggestions, and I appreciate them.

Regarding separation, how much is enough? Would it help to run wires at the top and bottom of the transmission tunnel? Is a three-inch separation enough to make a difference?

Thanks!

 

lol -- anyone feel like running magnetic flux calcs?

i don't know if that's enough or not... if no one else can answer, i'll pull out my books and make the calcs to see what the field will be like 3" away. the power is super easy to run up the passenger side doorsill... there's a little plastic channel in there and everything... pull up your footrest on that side and look under the carpet. you'll see what i mean immediately.

 

Magnetic flux calcs? That sounds like a lot of work!

I thought perhaps it was something everyone but me knew already. I expect it'll be easier for me just to run wires through different parts of the car.

Thanks!

 

well, the fundamental reason that the power affects the interconnects is due to magnetic fields that are generated by power flowing through wire... (think electromagnet) to have an idea of whether or not it would effect your interconnects at 3 inches, i'd have to see what the change in mag flux was at that distance vs closer or father... i seem to recall it's an exponential function, so after a bit of distance, things drop off very rapidly...

still, i haven't done those types of calcs in years... so, unless someone knows the 'practical' rule of thumb, you're stuck w/ my theoretical analysis.

 

Since the heaviest power flows will be through the power wires, you don't have to worry about them too much since their mostly DC. RCA cables are of such low voltage (and shielded) as to not contribute to the EMI issues significantly enough. Enshielded speaker wire, on the other hand, has much higher coltages at varying frequencies, so those are the ones you should be concerned about.

It will be a function of distance, as stated...squared, to be exact.

 

[QUOTE]Originally posted by MacGyver
[B]Since the heaviest power flows will be through the power wires, you don't have to worry about them too much since their mostly DC.