One way of measuring often applied is to take note of the output frequency and amplitude as it comes out of the amplifier using an oscilloscope and compare it to same at the input of the speaker. Interestingly, it seems that although measurable, it matters little to listener preference.
There are numerous blind tests where listeners can't tell the difference between a big box store cable like Monster and coat hangers [ https://gizmodo.com/audiophile-deathmatch-monster-cables-vs-a-coat-hanger-363154 ]
But what if you use better cables and invite self professed audiophiles to listen? Here's an interesting article from Stereophile magazine where such a test was done. What I find interesting is that the second highest rated cable in the test had the worst fidelity, and the worst rated cable was right there in the middle when frequency and amplitude were measured.
[ https://www.stereophile.com/content/minnesota-audio-society-conducts-cable-comparison-tests-0 ]
There are numerous blind tests where listeners can't tell the difference between a big box store cable like Monster and coat hangers [ https://gizmodo.com/audiophile-deathmatch-monster-cables-vs-a-coat-hanger-363154 ]
But what if you use better cables and invite self professed audiophiles to listen? Here's an interesting article from Stereophile magazine where such a test was done. What I find interesting is that the second highest rated cable in the test had the worst fidelity, and the worst rated cable was right there in the middle when frequency and amplitude were measured.
[ https://www.stereophile.com/content/minnesota-audio-society-conducts-cable-comparison-tests-0 ]