Quick question, going to running some in ceiling wiring for my speakers soon, is pvc pipe okay to run the speaker wire through? i've heard that the pvc doesn't offer any sort of protection from electrical wires. i've also heard that it does. which is it?

thanks

You're probably asking about electrical interference -- conduit (whether it be regular PVC or gray electrical conduit, etc.) would provide minimal if any protection against EMI.

PVC is fine -- make sure to avoid tight turns -- use street ells (for example) and wide radius turns otherwise you'll have a hard time fishing cable through it.

PVC protects wire from criters but not EFI/EMI. Use a good twisted pair wire.

High strand and copper content.

14 guage for under 50' and 12 guauge for over 50'.

is there any way to prevent efi/emi interference? I am definitely going to have recessed lights in the same ceiling space as the speakers/speaker wire. Will using a thicker gauge wire mitigate the effects?

thanks

Try to keep speaker wire 18 - 24" away from AC and LV. If you have to cross use a 90 degree angle if possible. Use twisted pair speaker wire.

Use MC [I think that is what is called] AC spiral metal wrapped lines or put the AC in a ferrous metal conduit.

mmiles thanks for your responses. been a great help but I have a few more questions.

first, will this speaker wire work?

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10239&cs_id=1023901&p_id=3844&seq=1&format=2

second,

I'm already using BX cable. Does that count as AC or MC?

mmiles thanks for your responses. been a great help but I have a few more questions.

first, will this speaker wire work?

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10239&cs_id=1023901&p_id=3844&seq=1&format=2

second,

I'm already using BX cable. Does that count as AC or MC?

That speaker wire would be perfect.

Robert

Speaker wires are basically immune from EMI pickup. You can run them in parallel with AC cables for tens of feet with no issues.

Just keep in mind a powered sub woofer cable is a line level and not a speaker signal and can pick up EMI/RFI. So observe the general practices noted above like only 90degree angles to power cables and at least a foot away. But these practices can be ignored for true speaker signals.

Glimmie,

Good to know. Obvious two different kind of signals for sure but, not to disagree just to "but", the speakers cables are connected to the amp which in turn is connected to the surroun processor [ or just to an AVR ] with that said is there any chance "stray" interference can find its way back in the signal path?

I know two different signals and off course post and pre processed if you will.

One more note. While helping our church install the AV system we ran out of speaker wire! I went back to the shop and grabbed a spool of 12 guage from Liberty [vs. the wire we were using from CAROL CABLE].

Later that night I examined both wires. The twist per foot were very similar and inside they were very close in "wire count" [and I assume copper contect] the main difference was the jacket. The Liberty had a softer thicker white cover that gave an "EEEW AAHHH" affect since it was some much thicker [the wire inside was about the same to my eye] were as the CAROL was a stiff PVC type jacket.

I do have a powered sub-woofer. So you're saying I may/may not get some interference? I will follow the basic guidelines above but the possibility still exists right?

Also, I'm using BX cable throughout my house. Is it considered teh armored cable (AC) or the metal cable (MC) you mentioned?

Thanks

BX is armored cable, here's a link:

Description of MC, BX differences (http://ecmweb.com/construction/electric_working_metalclad_cable/)

Glimmie,

Good to know. Obvious two different kind of signals for sure but, not to disagree just to "but", the speakers cables are connected to the amp which in turn is connected to the surroun processor [ or just to an AVR ] with that said is there any chance "stray" interference can find its way back in the signal path?

I know two different signals and off course post and pre processed if you will.

It's entirely possible but unlikely IMO. This would also only occur with RF. If you live next to an AM radio station, then I would not be surprised if you had problems. But then, where the power cables were in realation to the speaker cables would probably not much matter. Could the power cables act as antennas for the RFI and induce that into the speaker cables? Yes but now we are even farther down the probability scale. If you have that much RF on your AC lines, it will find other paths into your gear long before the speaker wires are a concern.

Given the option I too would keep any AV cables, high level speaker included, away from AC lines. But if you are in a bind in your construction and can't practically avoid it, it's not really a problem.

I do have a powered sub-woofer. So you're saying I may/may not get some interference? I will follow the basic guidelines above but the possibility still exists right?

Also, I'm using BX cable throughout my house. Is it considered teh armored cable (AC) or the metal cable (MC) you mentioned?

Thanks

Yes, the feed to a powered sub woofer is a low level signal feeding a powerful amplifier. So any noise on the wire gets amplified along with the signal. Also keep in mind what a sub woofer is for. Reproducing low frequencies. A 60hz sinewave is a perfect frequency for any sub woofer to reproduce with great accuracy.

Of course aluminum MC is better than ROMEX and steel BX better than MC. But with a line level sub woofer feed, nothing beats just keeping the reccomended distance from power lines.

oh man...thanks!

you guys are the greatest. thanks for all the advice.