I see the issue with ABX blind testing

@audphile1 
How do you explain cables being //Not difficult to hear// but impossible to see on a frequency or amplitude graph? Are the cables making a difference in sound apart from frequency and amplitude? I honestly want to know what you think. 

Measuring something is both an art and a science.  It is called Metrology.  The methodology to measure something is just as important as the measurement equipment used.  Let‘s consider an interconnect cable.  What could we measure?  Well, we can measure length, weight, diameter.  We can measure tensile strength, flex strength, minimum bend radius, hardness of the wire, wire gage, etc.  The list can grow quite long.  Then we can measure it‘s electrical properties.  A cable has resistance, capacitance and inductance.  But those three properties are not fixed.  They can vary with temperature, frequency of the signal passing through and amplitude.  Let‘s say we measure this interconnect cable with an LCR meter.  We get a value for resistance, capacitance and inductance.  That measurement doesn‘t say anything about a signal passing through at 5000 Hz or 10,000 Hz or 20,000 Hz.  I remember cable makers back in the 1980s touting their audio cables could pass signals in the MHz range.  I wondered what use was that?  Well, now I understand that harmonics in cables up into the ultrasonic range is important to the sounds within our range of hearing.  So the properties of that cable will cause the phase angle to change between the input and output but the amount of change is dependent upon the frequency.  I‘ve never seen anyone map that in a cable measurement.  How about a waterfall plot of an interconnect showing impedance, and phase angle across a frequency range from 0-100,000 Hz? One cable vs another will have phase angle changes that are unique.  Non-linearities.  Non-linearities are the biggest headache in engineering.  Hard to predict the outcome without some extensive computer modeling.  And in the end, what measurements we see on a graph could be smearing over what is so easily heard.

Another example:  How mechanical vibrations can affect the sound of a cable.  How can that be?  I don‘t know, but I have heard the difference between an isolated cable vs one that is exposed to mechanical vibrations.  My guess is that movements of the wires inside the cable alter the capacitance and inductance- an additional complication.  These minute mechanical changes create colorations in the sound, smearing of images.  I bet cable manufacturers know or understand much of this but they aren‘t about to give away trade secrets to how or what they measure as well as how they manufacture.

Another way to measure a cable that came to mind is a Bode plot.  The X-axis is frequency, say 0-100,000 Hz and then two lines on the Y-axis.  The first line would be amplitude ratio, input over output and the second line on the Y-axis would be phase angle.  Now I know the changes in those two lines for a cable will be very small- nothing like an amplifier circuit; but variation will be there.  Again, easier to hear than to measure.

Because we can evidently hear differences with many cables we can or we will measure differences ... Thanks for the video audphile1 ...😊

But generally as a factor of S.Q. it is secondary...It is why cables threads are boring for me... 😊