Multicore wiring

jlarcombe · Post by **jlarcombe** » Wed Jun 30, 2004 8:36 pm

Our house is being re-wired in a few weeks, and I thought I'd take the opportunity to lay some multicore cable while the floorboards were up. I have my studio in an upstairs room but often use the living room as a live room (it's larger and contains my piano) so running leads up and down the stairs is becoming a pain!

The problem is that the audio cable has to be laid alongside mains AC. I realise this is not a good idea, but for various practical reasons there's nothing I can do about it - either I lay the cable here or don't bother doing it at all. We can however put the cable in copper pipe for most of its length, which hopefully should ameliorate the problems.

Knowing this, I planned to use Sommer Mistral cable, which is double-shielded. The 12-way cable would be sufficient (13mm diameter) and I'd like to terminate it at either end in an 8 XLR + 4 jack wall box (with the cable running from the floor up a channel in the wall as normal). However, I'm a little concerned that a cable of this weight won't manage the tight turns required from floor to wall and from wall to mounting box. Does anyone who's done something similar (in a domestic setting) have any advice?

Many thanks,
James.

Post by **Aaronw** » Wed Jun 30, 2004 11:14 pm

How far apart will these cable be running next to each other. You're right, it's not a good thing to run audio cables parallel to electrical cables. Your cables will pick up interference from the electrical. Can the cables be run in another stud cavity?

Aaron

jlarcombe · Post by **jlarcombe** » Wed Jun 30, 2004 11:37 pm

Possibly the audio cable can be laid in the next stud along for much of the run, but it will definately have to be next to the AC when they all descend from the top floor to the bottom floor.

Is it a waste of time? And even if I get the cable laid, will it be too inflexible to go from the floor to run up a channel in the wall?

J

Post by **Aaronw** » Fri Jul 02, 2004 2:26 am

Most audio snakes are reasonably flexible. Can you post a drawing or picture of what you've got or trying to do? Maybe some measurements? If you're able to separate the snake from the electrical by having (let's say the electrical on the far side of the one cavity and the audio snake on the far side of the other cavity) giving some distance from each other, you should be ok. (I don't know the metric numbers so I can't be more specific nor do I know how far apart the stud spacing is in European construction???) Is there a reason why they need to be together going from top to bottom?

knightfly · Post by **knightfly** » Sat Jul 03, 2004 6:34 am

If you're not on a real tight budget, and are not trying to maintain a totally analog signal path, there are solutions out there that convert all your multi-channel audio to digital and then you only have to run a single Cat-5e cable for at least 8 channels - this would eliminate the necessity for separation of audio/power. Otherwise, expect a constant hum level (50 hZ in your case) - you can certainly do all the standard things to cut that down, but in the end the best way to get rid of noise is to NOT generate it in the first place.

Some links for study;

http://www.rwonline.com/reference-room/ ... ne_5.shtml

http://www.rane.com/pdf/cobrapps.pdf

http://www.qscaudio.com/pdfs/raveapgd.pdf

Don't have time to get into this much further; also, haven't had time to dig into it much myself. Still, looks promising for some things. Cost is not cheap, seems like I saw prices of around $1-2k for both ends of a 16 channel system, not positive though... Steve

AndrewMc · Post by **AndrewMc** » Sat Jul 03, 2004 7:34 am

If the cable is tight up against the mains for a long run then you will get some induction and interference. If you can get a few inches distance between the cables then you should be ok.