I guess Physics, Chemistry is involved, not surprising since a musical signal/current occurs at the atomic level.
What the author explains occurs and is dealt with in other areas, such as steel production, car manufacturers,
so obviously applies to electronics. So more than just resistance (which is different), capacitance, and inductance.
With wire and resistors designers and manufacturers have to consider rough surfaces, and internal boundaries due to impurities. Both create eddy currents and noise. A stream analogy is that of fast moving water with rocks in the middle and at the banks.
Mating different materials, plugs, jacks etc, is similar to junctions, etc. Galvanation, rectification effects, thermal coupling can and do occur. His video doesn't cover such.
The comment about diodes in ics is puzzling. If diodes are placed in series, then we have the junction barrier to overcome, so large distortion. If in parallel, then a simple 2 volt p-p signal will be clipped. If a resistor in series with the diodes, what good is that? If a zener diode, or back to back zeners are used, then nothing happens until the zener(s) breaks down and clips the signal. I would sure like to know what brand interconnect cables (ics) have diodes incorporated.
By the way, the limited frequency graph response at +50 and +80db manipulates the rise time
(layman might call it “speed”) by manipulating the frequency response (FR). So the original signal is
altered, and some low level information is lost due to filtering (just like a power supply supply filters).
Might also consider the quality of the parts used.
We all know that different model/manufacturers components sound different. One may allow more
small signal inner detail to pass than another component which is masking low level information.
For instance, slightly bass heavy would cause such a condition.
Yet both have the same specs. As an example, +/- 0,1db from 20-20khz means a deviation can occur
in the range of only 54db down from the fundamental. That is easily perceivable. The question is,
how do we know his "null tester" is not masking low level signal information, and is truly transparent?
How does the "null tester" cancel "smearing" of a signal, depth, just small signals etc., all of
which involve moderate to extremely low level signals? (This assumes that no masking is
occurring.) First, if smearing is not cancelled, what are you actually going to perceive but
nonsense, noise. Combining it with the fundamental, it will compliment the fundamental again.
Another issue, if the moderate to low level musical information is canceled beyond perception
with just 10db to 40db of cancellation, how can a null tester demonstrate that there is not
low level differences in two different wires.
Example. If cable A produces a small signal X, and cable B produces a small signal X but at a different level,
and 10db to 40db cancellation reduces both signal Xs to below noise/perception, the null tester won't
distinquish the difference between the 2 wires. However, during regular listening, the original musical
signal is present, and we hear the sonic difference.
At 25:00, 25:55 look very carefully, the scope is showing differences at null, not just noise. However,
his maximum scope sensitivity is 20mv/division (20,000 microvolts/division). I don't believe he mentions
the scope's sensitivity, correct me if I am wrong,
He states, if phase is shifted by a mere .005 degrees, nulling is limited to -80db. (Turn table rumble is
typically 70db down. At least it used to be.) Did I miss how he measured the accuracy of
phase shifting of his tester? If I missed it, I apologize.
I see the same problems in the video as the two "typical
frequency response room graphs" he posted
some years ago on another forum when arguing about frequency response perception. The first graph is
from 20-200hz, the second is from 200-20khz.
Does this appear to be a typical frequency response (FR) in a room to you? According
to him, the graphs were measured using a Mackie HR824 2 way speaker
with 8" woofer and 1" dome tweeter (in a quasi horn configuration).
For those who don't understand the graphs, he claims to measure a 40db variation in
frequency response in each graph, in a typical room. In the second graph, not just peaks,
but actual roll off in FR.
Lastly, in my decades of listening testing, with others involved, I find, as others, that silver wire to
be brighter than copper wire.
So my conclusion is I am sorry I cannot concur with many here, that the video is educational or scientific. I wish
I could say otherwise.