Speaker wiring

[dlminehart]

I'm wiring my family room for 5.1 sound, and allowing for the entertainment center to be on either side of the room. This means that the 2 speakers on wall A and the 2 speakers on wall B might be either front or rear speakers, depending on where the entertainment center goes. I'm trying to figure out how to best wire for this.

To make the following discussion simpler, let's assume I'm doing mono rather than stereo, and ignore the center speaker and woofer. Call one wall East and the other West. So I have speakers Spkr-East and Spkr-West, on opposite walls. If I put the receiver next to the East wall, Spkr-East is front speaker, Spkr-West is rear. Spkr-West requires a wire that wraps halfway around the room, while Spkr-East's wire just stays in the East wall.

On the other hand, if the receiver is next to the West wall, Spkr-West = Front, Spkr-East = Rear. Spkr-West has the local wire, Spkr-East has the wire wrapping to oppositve wall.

I want to have boxes in the walls, with attachment posts for the wires from the speakers, and to which the receiver can also be attached. Let's call the boxes Box East-Local, Box East-Remote, Box West-Local, and Box West-Remote for the east and west wall front and rear speaker attachment points.

Then, here is on possible configuration set:

Rec'r on East wall:
Front speaker: Receiver -> Box East-Local -> Spkr E
Rear speaker: Receiver -> Box East-Remote -> Box West-Local -> Spkr W

Rec'r on West wall:
Front speaker: Receiver -> Box West-Local -> Spkr W
Rear speaker: Receiver -> Box West-Remote -> Box East-Local -> Spkr E

This requires two sets of wires to wrap around the room, one from each of the "Remote" boxes to the corresponding "Local" box on the opposite wall.

I'm wondering whether there isn't a way to do this using a single cross-room wire and 3- or 4-way switches instead. Save me drilling more holes and running another set of wires. Seems that this would require having doubled local wiring, alternate parts of which would be switched on or off but still be connected to the speakers. I wonder whether these present-but-dead wires could result in hum or static or whatever.

Any ideas?

[LCHIEN]

you lost me on all the speakers and wires and boxes.

As for speaker wires picking up hum and statis, that almost never happens since the speakers and drivers are all very low impedance.

[knotley]

Although more for networking, I have found this site very very useful. There are a few tables for minimum spacing of wires and lots of links.

http://www.swhowto.com/index.htm

[Rand]

The dead wires won't cause a problem. Runing speaker wires right next to power cables can cause interference. It's okay to cross them

Unless I was able to commit to where the amplifier would live I wouldn't use boxes. I would drill small holes in the floor or ceiling for the rear channel speakers. If you decide to move the wires later you can patch the little holes with spackle. It's really just aesthetics. I don't think blank box covers look that great.

[dlminehart]

I'm putting boxes where the entertainment center would go. One, recessed into wall, has 2 AC receptacles and 6 modular sockets that'll contain Ethernet, cable TV, and the 2 sets of red and black speaker jacks for the "local" (front, on same side of room) speakers. Adjacent box will have 4 modular sockets for the 2 sets of red and black speaker jacks for the "remote" (rear, other side of room) speakers. I'll do as Rand suggests, putting holes in wall right behind the speakers themselves, once I decide on their location. To enable this, I'm draping excess speaker wire between the possible studs, accessible through the drilled hole.

[dlminehart]

Diagram

Here's a diagram of what I'm considering. The circles are speakers, on opposite walls. The small vertical rectangles are in-wall Front and Rear boxes with speaker wire posts in front, connected to speakers behind. The red and green receiver boxes represent the two possible locations of the receiver. Only one would be in place at a given time. The switches between each box would have to be toggled oppositely -- i.e., when one is open, the other must be closed.

Does this look to you like it would work, as an alternative to running an extra set of wires from one side of the room to the other?

[JimD]

I do not know how to do this without running two sets of wires. If you put switches into the wires you risk adding impedence and making the signal worse to the speakers.

My way of wiring our family room for speakers was to run 16 gauge zip wire from a large electrical box where the receiver would be to one outlet boxes where the speakers would be. I coiled up about 3 feet of wire at each end and taped it up so it would fit into the box. The sheet rockers put the sheetrock around these boxes the same as all the other electrical boxes. I bought blank covers for the electrical boxes and put a 1/4 hole in the center for the wires to come out of. That way, I connect direct to the speaker or receiver. No terminals to buy plus no chance to degrade the signal.

For your situation, you could run wires of two different colors for the two sides of the room. There should be room enough in the box for both.

Jim

[430752]

not sure I grasp fully what you mean by 3 or 4 way crosses, but I'd run dedicated lines for each speaker location. Zip cord is cheap enough, and small enough. If you mean that you'd run them into a speaker selector and use that to switch, I guess it could work, but why go through the trouble? Just run 8 sets of zip cord (8 lines for 4 speakers) and hook them up later, dead/unused wires wouldn't matter.

The only advice I can give is to keep speaker wires away from electrical wires, and to cross them rather than run alongside them. Also, I'd try to keep away from data transmission also, but less important there. Finally, while I think it is not a big deal, many people say to keep speaker wire lengths equal, unless to run unequal wouldn't be more than 10-20% different. This is to keep the same impedance showing to the amp, the idea being a 3 foot run shows different impedance to an amp than a 30 foot run. I dunno about it, seems it wouldn't drop that much to make a difference unless you got to something like 100 feet, but again since zip cord is so cheap why risk? Of course, if running monster cable, or worse MIT Cables or Tara Lab cables, then good luck!

[dlminehart]

I don't think zip wire is up to code for in-wall installations. Needs to be CL2, CL3, or above.

[cwithboat]

I don't think zip wire is up to code for in-wall installations. Needs to be CL2, CL3, or above.

Oh come on. If you can run door bell wire in a wall you can run zip.

[pelligrini]

Most jurisdictions refer to the NEC and its pretty sparse on most low voltage wiring. I ran across this article a while back. It looks pretty well written, but I haven't really checked it against the NEC. I probably never will, as I only prefer to open the NEC if I absolutely have to. From what I've seen around here the inspectors really don't look at any low voltage wiring before we cover it.