I want to tell what happened last weekend when I was invited to modify an
active crossover. The owner had already told me that by changing the
interconnects and also the speaker cable there was a tremendous impact on
the sound, and he demonstrated it to me as well. Really even the wife in the
kitchen would have heard that, I have to agree even if my experience tells
me something else.
The amplifier was one of these audiophile English brands 40+40W. The load
was a 10" visaton chassis with a minimum impedance of 6.3 Ohms. When I tried
to measure the LS-impedance my gear was complaining about overload and made
all kind of funky curves, so I looked at the signal with the scope and found
that amp oscillating at quite a level. The customer used to drive the treble
speakers with it(some Manger MSW) and had already switched to the Rotel
which was supposed to drive the bass, because it sounded much better.
Looking at the "audiophile" amp showed a crappy layout apart from the hood
being made just of laminated fiberboard without even an aluminum foil
shield. the decoupling caps were put to a wrong potential and were even
coupling more ripples into the output signal, the Zobel R/C at the output
was blown because of only a quarter watt resistor and there were no
compensation caps in the feedback loop. After fixing these flaws, the amp
would act nicely as intended.
Really incredible the sonic alterations depending on the cables. Just half a
meter longer interconnect would create some awful whistling sounds in the
woofer, so my customer had already exchanged his high capacitive expensive
interconnects with cheaper short RCA-cables that would sound better. He was
on the right track.

--
ciao Ban
Bordighera, Italy