Twisting and Braiding Cables

[ralph-bway]

Hi everyone. A kind of general question about twisting and/or braiding cables.

The speaker cables at http://www.geocities.com/jonrisch/cables.htm
seem very interesting. Jon's instructions are to twist the pair of belden coaxel cables used for each speaker. I'm thinking of using a bi-amp system (dual subs up to 250hz and electrostatics above).

Since I have to run four cable for each channel, would it be better to braid the four cables together and split off the pairs on each end running from the appropriate amp and speaker, or should I just twist one pair for the sub and twist another for the esl. I ask because of the many threads describing braiding belden computer cable.

Please excuse me if this is a silly question. Thanks for the help.

Best,
Ralph

[haldor]

Not a silly question at all.

However suggesting someone twist pairs of coax cable is pretty silly, since the shield in the coax makes this technique totally ineffective (twisting only works with unshielded wires, you can put a shield over a twisted pair, but if the individual wires are shielded then twisting does no good at all).

Coax cables are designed to provide full coverage shielding with specific characteristic impedance. Neither of these attributes matter when driving a speaker. Coax does not normally have very large diameter center conductor. Depending on the cable chosen it could negatively effect the amps dampning factor.

An amp's output impedance is measured in fractions of an ohm. The speaker input impedance itself is below 10 ohms which makes this circuit very unlikely to pick up audible induced noise. For audio frequencies the cable length would have to reach several miles before you would need to be concerned about transmission line characteristcs of the cable.

In my opinion, the best speaker cables are short and fat. If you want to invoke wire vodoo, then try the Cat5 style cables. These are cheap and shouldn't create problems (unlike some audiophile cables that can make some audiophile amps unstable and oscillate).

To answer your guestion, the subs and tops wiring are not carrying the same signal so I don't think twisting them together would be a good idea. If you go with coax then twisting won't actually do anything in which case this will not be a concern.

Phil

[ralph-bway]

Hi Phil,

The cables I'm talking about use TWO coaxels for each speaker lead. The center of each coaxel is crossed over and soldered to the braid of the other coaxel.

You can see pictures and instructions for the cable at the link at the top of the page or here:

http://www.geocities.com/jonrisch/cables.htm

I've seen this cable referred to by a couple of sites and the general opinion is very high. After you take a look at it you'll see why I was asking about braiding & twisting.

Thanks again & I look forward to hearing from you.

Ralph

[fdegrove]

Hi,

However suggesting someone twist pairs of coax cable is pretty silly, since the shield in the coax makes this technique totally ineffective (twisting only works with unshielded wires, you can put a shield over a twisted pair, but if the individual wires are shielded then twisting does no good at all).

The idea is not novel but that's not important.
Without looking at the weblink, I guess the braid serves to provide a low impedance for high frequencies, whereas to central conductor (often solid core) would serve the lower regions?

Ah! If only something was telling the electrons which way to go??

Cheers,

[maynardg]

I braided the 4 89259 cabels together. A primary benefit is keeping them neat for the spouse.

[badman]

Twisting the pairs for the two speaker cables separately is the way to go. Combining all four makes for greater crosstalk.

[ralph-bway]

I had this wonderful arrangement with the spouse. She got to do whatever Martha Stewart, Trading Spaces thingie appealed to her throughout the house, except in the den, where I had the final say, that is after exhausting about 10,000 "Oh, by the way" and "You know I was thinking" and "Are you really sure you want to do that". All of which were accompanied by the appropriate facial expression.

Then I got smart. I bought a gallon of flat black paint home and presented it as the ONLY other option.

Now besides the DIY lock she installed on the outside of my den's door, we have peace again, well kinda'.

[Steve Eddy]

Originally posted by badman
Twisting the pairs for the two speaker cables separately is the way to go. Combining all four makes for greater crosstalk.

Hey my main badman!

Worried about crosstalk? Disconnect your left channel. Play some music. Plug your right ear. Everything you hear after that is crosstalk.

se

[haldor]

Originally posted by ralph-bway
Hi Phil,

The cables I'm talking about use TWO coaxels for each speaker lead. The center of each coaxel is crossed over and soldered to the braid of the other coaxel.

You can see pictures and instructions for the cable at the link at the top of the page or here:

http://www.geocities.com/jonrisch/cables.htm

I've seen this cable referred to by a couple of sites and the general opinion is very high. After you take a look at it you'll see why I was asking about braiding & twisting.

Thanks again & I look forward to hearing from you.

Ralph

I looked at Jon's explaination page: http://www.geocities.com/jonrisch/s1.htm. It is easy to to take comments out of context from someone's work and use them to make cheap shots, but I am not going to do that. I agree in general with his objectives. I do wish he had gone into detail about the advantages that his double coax has over regular wire.

I think this is mostly an attempt to reduce cable inductance, or perhaps it is simply to provide a more stable physical geometry. It's hard to imagine either of these mechanisms being an issue if you use properly constructed wire.

From Jon's website:

"Important Design Considerations:
...
Minimal Cable Inductance (try to keep to 2X resistance @ 20 kHz, this controlled through geometry)
...
Maintain Physical Geometry under signal conditions (minimum
"magnetostrictive effect" or motor action between hot and ground strands causing motion and induced EMF's) "

Ignoring these issues (minor in my opinion), these speaker wires are effectively two hollow braided straps with insulating cores and insulating jackets. Since the hollow insulating core will force the braid to maintain a round cross section they will have a very slightly lower impedance at high frequencies than a flat braided conductor of the same size does.

Given the amount of copper in these cables, they should make exellent speaker wires. I seriously doubt if you will notice any difference in sound quality if you don't bother hooking up the inner conductor of the coax. Using the configuration Jon recommends shouldn't cause any problems so use it if you wish. Since the outer braid is the current carrying conductor then twisting them will have it's usual effect on reducing radiated EMI and susceptibility to induced EMI.

Go for it! And don't braid the subs and mains cables together.

Phil

[mrfeedback]

These work really well and are cheap.
And no WAF problems.

Eric.