How much cable length is too much? Options

[John 31415926]

I just rearranged my home office and the Mac (running iTunes) is now about as far away from the receiver/amp as it can be. It's looking like the only way to connect the Mac to my receiver is to run an audio cable up the wall, through the attic, across the room, back down the opposite wall, and into the audio system ...

... to the tune of about 40 to 50 feet of cable distance.

I think I had a length like this a while back and I vaguely remember getting some hiss, although I don't know for a fact if that was the cable length causing that or something else.

Right now I've got a spool of 18 gauge speaker wire, would that do the job?

I guess it's two questions.

1) How much length is too much to connect a computer to a receiver?

2) What gauge wire is required for such a length?

[botface]

I just rearranged my home office and the Mac (running iTunes) is now about as far away from the receiver/amp as it can be. It's looking like the only way to connect the Mac to my receiver is to run an audio cable up the wall, through the attic, across the room, back down the opposite wall, and into the audio system ...

... to the tune of about 40 to 50 feet of cable distance.

I think I had a length like this a while back and I vaguely remember getting some hiss, although I don't know for a fact if that was the cable length causing that or something else.

Right now I've got a spool of 18 gauge speaker wire, would that do the job?

I guess it's two questions.

1) How much length is too much to connect a computer to a receiver?

2) What gauge wire is required for such a length?

I run a cable from my PC to an amplifier in a different room via the roof space. Overall it's about 70ft. I took no care at all about avoiding other cables in routing it and there is a very faint hum on 1 channel but you can't hear it unless you put your ear right up against the speaker. I used microphone cable. Not because it has any special audio qualities but because a single mic cable is able to handle separate left and right channels as it contains 2 signal leads inside a shared screen. It is slightly fiddly to solder up as you need to split the screen to "share" it between 2 plugs (I assume your receiver uses RCA plugs) so you might prefer to use conventional 2 channel cable. I'd say try it and see. It's much cheaper than any wireless solution so you've not got much to lose if it doesn't work out

[greynol]

I used microphone cable. Not because it has any special audio qualities but because a single mic cable is able to handle separate left and right channels as it contains 2 signal leads inside a shared screen.

Not a bad idea except for the possible dramatic increase in stereo cross-talk.

I'm tempted to use that to reduce the number of cords running across the floor to and from the pedal board in my guitar rig but instead of coupling left and right, I'd be coupling ins and outs which could lead to feedback problems.

This post has been edited by greynol: Jul 19 2012, 14:48

[punkrockdude]

I'm tempted to use that to reduce the number of cords running across the floor to and from the pedal board in my guitar rig but instead of coupling left and right, I'd be coupling ins and outs which could lead to feedback problems.

Can two wires seperated from each others by plastic coating inside a cable cause feedback? Sounds interesting. Can you explain the details, please? Regards.

[Arnold B. Kruege...]

I'm tempted to use that to reduce the number of cords running across the floor to and from the pedal board in my guitar rig but instead of coupling left and right, I'd be coupling ins and outs which could lead to feedback problems.

Can two wires seperated from each others by plastic coating inside a cable cause feedback? Sounds interesting. Can you explain the details, please? Regards.

It is common practice to put mic input lines (very sensitive) and line-level outputs for driving monitor amplifiers on stage (far higher signal voltages) into the same cable, provided each connection is a shielded pair and balanced inputs and outputs are involved for at least for the mic lines.

[greynol]

It is common practice to put mic input lines (very sensitive) and line-level outputs for driving monitor amplifiers on stage (far higher signal voltages) into the same cable, provided each connection is a shielded pair and balanced inputs and outputs are involved for at least for the mic lines.

Of course we weren't talking about each individual connection consisting of a pair of conductors sharing a common shield carrying a differential signal; rather, we were talking about using the two conductors for two separate connections with the shield being shared as a common ground (i.e. each of the connections is single-ended).

This post has been edited by greynol: Jul 19 2012, 23:34