Listening test of dual coax wire

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Technical and scientific discussion of amps, cables and other topics.

A while back I made a dual coaxial cable, using braid that I pulled off a mike wire..I had purchased 500 feet of it from parts express..
I calculated the inductance and capacitance of the cable, then measured it.. It was extremely close to the calculations. (go figure)
Capacitance at 288 pF per foot. Inductance of 10 nanohenries per foot. Resistance unknown, but it is not a very large guage, I would guess 16 or 18 guage even..more on that.
I sent the cable to a gentleman on the west coast..he was kind enough to try it, and this is his commentary on the wire.
Note: I requested permission to post this effort, as well as his name, and his reply was:
""You can post what you want on Prop Heads and you can use my name if you wish, that way I'll be able to answer questions directly if need be""
(That was added to make it clear to all that posting the e-mail dialogue was acceptable to all parties, a condition I will not waver from.)
So, the following is e-mail dialogue between myself and Ted Smith.
Ted:
They were better than I expected :)
With sufficiently low listening levels they sounded pretty balanced low freqs to high freqs. But as we got to more normal listening levels, the bass got too weak, there was no prayer when we went to higher than normal, but still reasonable levels. One thing that's nice about my system is that there isn't any dynamic compression even 30dB above loud levels (the benefit of 700 watts into 8 Ohms amps into 92.5 dB efficient speakers which can take 450 watts continuous....) Your wires seemed to peter out at about 75-80 dB in my room with these speakers.
I don't know if it's related but on my 'acid' tests for things remaining stable in a congested soundstage, your cables did OK but not great. When things got really complicated (say full blown orchestra) individual solo instruments got lost. Similarly on some Vaughan Williams when the voice and orchestra came in the solo violin lost its character and when the triangles came in they didn't sound correct, perhaps a little glassy. On the Vivino Bros. Blues Band disc there's one track where a washboard is right behind a sax, with your cables the washboard just sounds like noise in the recording, with better cables it's enough behind the other instruments that (on a good system) it's in its own space and doesn't sound like noise.
John
From everything you are saying, I would immediately attack the guage of the braid..
Ted
Indeed it was our hypothesis that too small of a gauge was the root of all
evil :)
John
I am thinking that spacial imaging, like the washboard, if the timing is correct, focusses the image at a location in space, while, if the amp (actually, amp plus wire) "loses control", the speaker is not getting the instantaneous cues at the right time..so, I would guess that the washboard timing is sliding right to left, as a direct result of the sax power....
Ted
The sound of the washboard isn't sliding left to right, it's sliding too far forward. But sliding isn't the right word in that my cables have more front to back separation than your cables, i.e. with your cables everything is flatter front to back than mine. In this case it's not a question of things changing depending on the sax's instantaneous power the washboard is always too close to the sax with your wires. Note that this track on this disc is inherently congested, it was an unhappy accident that the washboard and sax
ended up at those exact positions relative to the mics on only that track, but I like it because on most systems people start looking at their wires, etc. trying to find the noise. But on a great system you can barely tell what's really going on.
John
Sliding was an incorrect term on my part, as I didn't mean a slow movement..I guess the best word I was thinking of was widening, or l-r blurring..words are failing me..
What is the mechanism of hearing that you use to discern less flat? Rhetorical question, of course..but I wonder..hmmmm...I'm gonna model L-R time delays for varying distances from the subject, off axis..something just came to mind..
I think at some point, we're gonna have to come up with some kind of common language...unless it's just my ignorance...
As for unhappy accident that the washboard and sax are in those positions...not exactly...I'd call it serendipity....

The purpose of a statistically reliable DBT effort is to be able to predict the outcome of tests applied to a more generalized population..Since I am not at this time interested in applying the tests of my cables to the general population, a DBT is not of use. That would come at a much later date.
The purpose of this endeavor is to determine how the lumped RLC parameters affect the sound of this speaker wire construction. To this end, further testing will be done, where only one parameter at a time will be changed. Initial iterations will be to assess the weaknesses in the cable..first case in point is resistance. My wire is too high in resistance, and probably causes too much IR drop and loss of damping.
I will next take the remnant, try to send it to Gene D for his tests (this is probably the first heâ€™s heard of it, btw)
I will next work on making a cable with the same L/C, but reduce the resistance by a factor of say, 5.
I thank Ted Smith for his efforts, as well as the un-named co-hort he did the test with..this is not overâ€¦not by a long shot.
Cheers, John

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Parts Connexion

Topic - Listening test of dual coax wire - jneutron 12:26:56 06/25/04 (2)

Re: Listening test of dual coax wire - Granholm 13:44:46 06/26/04 (1)

Re: Listening test of dual coax wire - jneutron 06:50:09 06/28/04 (0)

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