Cable Distortion

[laatsch55]

Ran some interesting tests just a bit ago. made up some XLR in's to XLR out's and hooked em up to the AP. I had in mind to see what distortion was present in the test cables themselves. Ran THD & N unweighted 10-80k like all the rest of the testing. I don't know what effect generator loading had, as the AP detects impedence automatically and sets the load , either 50, 600, or 20k. NOT EXACTLY surer on the numbers.
The test was run with Carol "CM" 20 gauge twisted pair with foil shield and bare ground. Terminated as a standard XLR connection.
The results were interesting. I had assumed voltage and frequency to have far less effect than there was.

Pics...................

 

[laatsch55]

Re: Copper Heatsinks

Further testing of the test cables, this time out to 120KHZ...... It appears at 12 millivolts the cables are contributing a fair amount to the distortion spec.


Starting at 14 Hz it appears the generator was struggling.

 

[laatsch55]

So, will smaller cables have less distortion at 12 millivolts than larger cables?

 

[mlucitt]

I think we are about to find out...

I think the biggest factor is the capacitance of the cable. It is small, in the pF, but the effect of the capacitance of the cable changes by frequency. Of course, the more cable length, the more capacitance due to the increased area, all other things being equal.

 

[laatsch55]

That's what I'm finding out. Could we be onto something in the voodoo cable debate?

 

[speakerman1]

No. Length has to do with freq. in RF. How did you test the cables? Have you tried more than 1 pair? Your capacitance can change due to the way the wire is made. Really I don't know but I stayed at a Holiday Inn last night. LOL

Larry

 

[Fairchild]

This is interesting, the only amp I have with balanced outputs is my Hafler Pro, I am using an XLR adapter pair that I bought. What are your feelings comparing the XLR's to RCA's?

Jim

 

[speakerman1]

Lee try the oh what are they called. You snap them onto the cables. When in doubt shield. Ferrite beads. To me the shielded shrink tubing is a cool idea.

Larry

 

[ksrigg]

I looked at this some time ago, and it does seem that capacitance is one of the major factors having to do with how a particulat IC, speaker wire, etc., sounds. It also has to do with interaction with the components and their parts upstream...I found a bunch of articles...Here is one:

http://www.ecoustics.com/electronics/fo ... /6528.html

 

[kevin]

Do yall really think the human ear will ever hear this difference in cables you have found ? OR... Does the fact that the paper tells ya thats it there make ya change them ? I know..... I know..... I have no business in this conversation..... lol...

 

[ksrigg]

That is something I have thought about for a long time Kevin. It falls under the study of "psychoacoustics" or the mind telling the ear what it should be hearing...for example..does XYZ cable sound better than ABC cable? Or does this DEF preamp sound better than the TUV preamp.....That is why I would love to have some "double blind" tests performed where people with good ears rate different cables or components without knowing what they are comparing...You'd have to set stuff up so you could do an immediate A-B between the different items you were comparing..

There is someone who has a $10,000.00 prize for anyone who can effectivly choose one piece of speaker cable out over others. I can't remember the particulars but NO ONE has claimed the prize money..I'll have to see if I can find the specifics of the challenge...They are out there on the web somewhere..I've seen it before..

 

[ksrigg]

Here is a Speaker Cable Face Off:

http://www.audioholics.com/reviews/cabl ... face-off-1

 

[laatsch55]

Kevin, did you notice a difference in the Tara cables?

 

[kevin]

Lee..... Ive not seen Sutton in a month of Sundays and here it is almost Sunday again..... I never did get the Tara cables...

 

[laatsch55]

He is scum!! You must have him come over with a couple pair, then you will see, or hear as the case may be.

 

[kevin]

Yea he sure as hell is !!!!!! We gonna try and get togrther here in a day or so.... He has to come down when his other half is at work..... She still thinks we are up to no good when we get together !!!! lol....

 

[laatsch55]

Smart woman, she must have good radar, some of them have EXCELLENT radar.