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SPEAKER CABLE <signal on +> <ground on ->


zman

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Is all the music that we hear traveling down the positive wire and the ground is just the ground? What is the ground wire contributing to the sound or detracting from the sound? The reason I ask is I'm making cables and I lose say 20% of the copper strands on the ground at both ends as I unbraid the ground on a coax cable.

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On 3/5/2005 2:16:46 AM customsteve01 wrote:

can I ask why are you using coax cable for speaker wire???

Steve

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I have been advised by Shanklipschfan that coax RG-58 works very well. Far better than, the now way too long, MIT 750 speaker hoses that I paid $1100 for back in the mid 80's. At 32 cents per foot at Radio Shack I figure why not try it. I'm also trying RG-8 which is much heavier than RG-58. Steve can you answer my question?

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On 3/5/2005 2:06:45 AM zman wrote:

Is all the music that we hear traveling down the positive wire and the ground is just the ground? What is the ground wire contributing to the sound or detracting from the sound? The reason I ask is I'm making cables and I lose say 20% of the copper strands on the ground at both ends as I unbraid the ground on a coax cable.

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both runs of the cable should be the same.........

and despite doing this audio thing for well over 10 years, i have never heard of anyone using RG-58 for speaker wire...

but it's your money

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To answer Zman's question.

There are many issues to it, but yes, the music is travelling in both sides of the circuit.

In line level set ups, like with phono plugs, the voltage on the hot lead is the music. That is referenced to ground. Both chassis should be a zero volts in a perfect world.

The ground loop problem comes up because one or the other chassis is not at ground and may have a slight voltage, typically a.c. hum. So one chassis is floating (has some low level a.c. voltage) while the other is not.

Using a cheater plug solves some problems in a poor way. It allows the chassis which is not at ground to "float" just like the other. Hence we have the same defective reference voltage. But humm goes away.

I believe the best solution is to have a grounding system which is independent of the shield side of the connectors. Hams use big braided wire to do so.

Getting back to the original question. The loss of some strands of the shield should not be an issue. However, anyone should not be relying on the shield to clamp the two chassis to zero volts. That is the job of an external strap.

Gil

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I see I missed the question. Our new buddy is not asking about line level at all.

The overall analyis is that if you're using coax, or anything else, every wire in the in the loop has an effect. I'd say that it is a neglible effect in this situation. But it is there in theory.

From your comment that you're losing some strands makes me think that you're doing things the wrong way.

The shield is braided in a cylinder around the central conductor and its insulation. It looks like a Chinese finger trap. I cringe at the potential racial and national slur - - not intended, naturally.

What you should do is take off the outer insulator for about three inches from the end. You're looking at the copper finger trap braid. Then, pull back on the braid so that it budges like a basket.

You can then create a gap between the braids near the remaining outer insulation and pull out the center conductor and its insulation.

You wind up with the braid narrowed down to a rope and an undamaged center conductor with insulation.

Gil

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I have been experimenting with the same idea. Logic tells me that wire is wire and that 18 gauge zip wire is more that enough for my application but it is still fun to try out different ideas. I have all kinds and gauges of wire strewn about my living room right now. Each type of wire "sounds" a bit different from the others - there are alot of smart people here and they seem to use anything from 6 gauge cable to lamp cord to very high end powered cables and all of these could be wound, braided or solid (well maybe not 6 gauge) and be made of copper, silver or kryptonite. There are so many variables to experiment with and it's one thing I can have fun with since I don't possess the skills and tools to actually open up my gear to test and tinker with electronics. At least, it's a way to learn something about wire.

In my week long experience of tinkering with coax, I have found that it is very difficult for me to strip the outer insulation without breaking strands in the braid. Instead of stripping, I use a knife and wittle away a line just to the braid down along the end of the cable and then just peel away the outer cover. I also found that it is best for me not to unbraid the wires but to enlarge an opening by pushing the braid back along the inner insulation (the way you "unlock" Chinese hand cuffs) and poking a pencil point between the loose braids to enlarge an opening large enough to push the inner core through (it's kind of tedious but it is easier to do after you've done it about three times). See if that might work for you Zman. Have fun.

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sputnik, THANKS thats great info. I would have messed up a bunch LOL trying to figure that out. Thank YOu.

As for wire is wire, I tend to agree with you Esp. with K-horns. But I thought it would be a fun project and didn't cost much I think total for parts was $150.00 and that was for a 100'. So there should be plenty left over to give his interconnects a go.

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Glad it helped. You're right, it doesn't cost much and it may or may not be an improvement, but it's fun to try and we could learn something. I think Wierd Al said it best when he said "dare to be stupid." That's a philosophy I live by whether I try to or not.

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zman, I just ordered everything on Friday. So I will probably get it mid to end of next week. I also have class next Friday night and all day Saturday. So it will proably be a couple of weeks, but I will be sure and message you or start a thread so you can follow. Guy

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Risch uses the coax in what he calls a 'cross-connected geometry,' where the prepared shields of the twisted pair are combined/connected with the opposing cable's center conductors. I made several different versions of this cable a few years ago, and it sounded about as good as the thermostat, CAT 5, power cord, magnet wire, garbage disposal power cord, stranded Romex (which was probably the most transparent sounding of all of them), and doorbell wire speaker cables I constructed. A particularly good sounding cable was also made from 18AWG silver plated solid copper under Teflon. A simple twisted pair of that was really good, although it won't have the heavy, dramatic sort of appearance of twisted coax pairs held together with heat shrink.

He states that, like the braided CAT 5 cables, the advantage of this particular geometry is it comparatively low inductance/capactance of parallel runs of thickly-vinyl-clad speaker cable, which happens to be what I now use and am at peace with. I experimented wo much with different types of coax and wire for interconnect and speaker cable that it just became, for me, ridiculous.

The advantage of the Belden cable over some others is the fact that it uses a bare copper braid (rather than tinned copper) and all copper stranded center conductor (rather than copper clad steel). Because of the Teflon insulation used for both the center conductor and outer jacket, it also has very low capacitance characteristics, which would probably be more of a concern at line levels than it does at speaker levels. Perhaps moreover, the output impedance of amplifiers is much lower than that of line level sources, so the difficulties encountered by high output impedances driving the capacitance associated with long runs of IC is maybe less of a concern with speaker level signals.

It can be fun to experiment with wire, and the main thing I have learned is that the stuff from Radio Shack or Home Depot works pretty well, too.

Erik

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Z-man:

You have to be careful when you srip the outer jacket off coax. Depending on the kind of wire used, some types are more brittle and more easily broken. What I do is use (carefully!) and X-acto knife to make a shallow cut around the entire section I want to remove. This doesn't penetrate to the shield itself, but rather 'scores' the cable in such a way that simply gently bending the cabel after the initial cut is made finishes the work of the X-acto knife. Then, carefully use the tips of your fingers at the base of the cut portiont to gently pull it off. I've used coax strippers before, but seem to destroy more of the shield with those things than with the X-acto knife approach -- which does take longer but keeps the shield intact.

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Wait, what a dummy....

Let me just say that those of you who made the investment for the Belden cable (which I wasn't willing to do at the time)could very well arrive at speaker cable perfection. I found some stuff locally that used both all copper braid (but solid rather than stranded center conductor), foamed PE center conductor insulation, but with a PVC outer jacket -- with is frowned on by many in the DIY and retail speaker cable communities. The cable I had actually was 2Pfd (picofarads) lower in capacitance than the Belden, a fact which made itself known with the striking triangle sounds on syphonic pieces. The two picfarad difference also increased the height of the soundstage by 2.5', which I meaured with a flexible measuring tape! :)

The Belden may make all the difference in the world, and you MUST TRY IT FOR YOURSELF to know if it is an improvement (or lack there-of)over what you were using before. I think my problem was that I have tried so many different kinds of cable and wire types that I simply lost track of what was what; and in confusion and dismay, abandonded those cables in favor of some RCA branded 14AWG fine copper stranded cable from Home Depot. I have since forgotten about cables, but you guys doing this might have some really good results!

Enjoy the work! Audio DIYing can be rewarding and tons of fun.

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