*WHITE PAPER* The Sound of Music - How & Why the Speaker Cable Matters


G'DAY

I’ve spent a sizeable amount of the last year putting together this white paper: The Sound of Music and Error in Your Speaker Cables

Yes, I’ve done it for all the naysayers but mainly for all the cable advocates that know how you connect your separates determines the level of accuracy you can part from your system.

I’ve often theorized what is happening but now, here is some proof of what we are indeed hearing in speaker cables caused by the mismatch between the characteristic impedance of the speaker cable and the loudspeaker impedance.

I’ve included the circuit so you can build and test this out for yourselves.


Let the fun begin


Max Townshend 

Townshend Audio



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Not IMHO kijanki, but absolute fact that at 7Mhz it will have no effect. At 1Mhz, worst case would be -170db down.  I would be careful with the 1000 meter example. In that case, the worse case would be -60db error at 20KHz, which could be argued as audible. That is worst case though. Odds are it will be much better.


The idea that 7m speaker cable is a transmission line for audio signals is insane, IMHO. For 20kHz signal you will need about 1000m long speaker cable (1/10 of the 20kHz wavelength) to even start becoming transmission line. In such case reflections would be inaudible because they are in MHz range (and because speakers are 1000m away).  Why not to use 20kHz sinewave for the test? It is the highest audio frequency component of interest in the cable. Please show me reflections of 20kHz sinewave in 7m cable. Any cable.

Let’s forget nonsense about reflections at audio frequencies and concentrate on frequency response. Increased characteristic impedance is not the reason for the signal attenuation at the high frequencies - increased inductance is. Same attenuation can be achieved by increasing capacitance. Higher dielectric constant insulation (same geometry) will increase capacitance, but inductance will stay the same. That way we will get bigger attenuation at high frequencies at lower characteristic impedance. Finding correlation between characteristic impedance and frequency response is pretty much like saying that tattoos are causing motorcycle accidents. Correlation, a very dangerous tool, assumes that if B happens when A happens, then A has to be causing B. It completely ignores the fact that both can be caused by C. In our case increase in characteristic impedance and increased attenuation at high frequencies were both caused by increased inductance.
Damn!
This is one of the worst spankings I have ever witnessed on any board on any subject.....
The only way to get a square wave out is to match the cable impedance to the load impedance. This is a standard way of determining the characteristic impedance of unknown coax cable. The trick was shown to me when I was working on the ill-fated Blue Streak Rocket development at the Weapons Research Establishment in Adelaide in the early 60s.
See my videos Geometry Matters on youtube.

Max
Audio2design is suggesting that transmission line theory does not apply at low frequencies. Well, it does, even at DC. see

https://www.youtube.com/watch?v=ozeYaikI11g&t=136s

And at 50/60Hz bigtime. 

Max