*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



F78318cb 1fc9 49a2 8d02 edd399ef66f5Ag insider logo xs@2xtownshend-audio
It correlates because spreading wires apart increases inductive reactance that is dominant factor here. 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.
Oh, and your "White Paper" shows 0.94uH/meter for Isolda, but your website shows 0.002uH but does not show a length.

I looked further into the Isolda, pictures and the dimension estimates I made.  I expect that 6.6uH is quite wrong, but that 0.002uH is quite wrong too (for 2 meters).


Given the lack of consistent numbers for Isolda, could be a function of the cheap meter, or measurement error, let's use the Isolda as a reference, use some of the inductance numbers in the chart, and the shown (but wrong) speaker simulator, using inductance only.

                    My Calcs    Value on  Graph
ISOLDA       2.6              2.6         (Used as ref)
                   8.5758         8.8
                   15.210        13.8
                   24.69          24.4

That's close enough to me, to show that inductance alone completely explains Chart 3, certainly within the framework of the obvious measurement errors.

Here is what you have done:
1) Showed a graph with expected change in frequency
2) Showed that order of magnitude characteristic impedance had a rough correlation to the measured results.

What you did not do:
a) Investigate other related effects ... like INDUCTANCE.b) Show a direct correlation via a measurement of impedance and measured error
c) Show a mathematical correlation between impedance and measured error.

See, I just did #3 above, and showed a very close correlation between inductance and the measured results.  That's science.

You also left out many necessary details so that your experiment could be corroborated.
And ...perhaps most of all, you did not relate your result to what the actual change in frequency response is.
On the very worst cable it is 0.4db at 20KHz.
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.....