Here it is again
Here is the latest experiment. The circuit is attached.
And here is a video.
https://drive.google.com/open?id=1HRRaiVVifHlSKF0A6B0ukfPLy4Enbc26
The Pink noise is from my phone on Audio Tool
The audio is from the Sheffield Lab test disc, only playing the left channel.
The amp driving the cables is a Cambridge amplifier
The second amplifier is a Nobsound Lindsey-Hood class A (an absolute audiophile bargain)
The speaker is a small two-way.
The spectrum display is from a calibrated microphone, 2 inches (50mm) from the middle of the speaker. The analyser is a
Behringer Ultracurve Pro DEQ2496 .
The camera is a Cannon G12. The sound you hear, is from the microphone in the camera, positioned about 3 feet away from the speaker and is a little "shrill" sounding due to the appalling acoustics. But you can still hear the difference, even on your phone!
The dummy speaker, is a hard-wired implementation of the dummy load, as represented in the simulations. (a real speaker would be very loud and swamp the other)
The circuit allows input selection to the power amplifier and the two cables under investigation are in parallel, connected to the output terminals.
The two way switch on the right selects the cable.
The object of the experiment is to observe the difference between the voltage on the send end and the receive end of the cable, by amplifying the difference between each end of the ground ("-") wire.
There is a clear difference between the cables, with the Monster exhibiting rising output, commencing at about 500Hz, rising by about 12dB+ at 20khz. In contrast, the Isolda produces a "rolled-off" sound. Further, the Monster sounds a fair bit louder than the Isolda, a bit masked by the AGC in the Canon microphone. If the differences were due to DC resistance, then the Monster should be 75% SOFTER than the Isolda.
In the case of the Isolda, the difference sound is due to the resistance loss only, whereas with the Monster, there is a resistance loss, similar to the Isolda, but with a huge amount of added high frequency noise due to the decay of multiple reflections.
The mathematics, the simulations, the measurements and the listening all concur.
Please try the experiment yourself.
I am pleased to answer any questions.