the mismatch will affect capacitance and resistance (also additional potential EM interference)...Hey folks, thought I'd drop in a cable question here:
At what point do mismatched cable lengths matter to the stereo signal, and what could be affected?
I presume that, for instance, connecting unbalanced RCA cables between a pre-amp to an amp, using a 3 foot cable for the Right channel and 6 foot for the Left channel would be unlikely to produce any audible issues. But then, at what point WOULD there be issues? How much longer would the Right channel cable have to be before problems arise? I presume one problem could be you hit high frequency roll off by sheer length. But, any other issues? Like a mismatch of the timing of the signal between left and right signals to the amp?
Same question goes to mismatched length of speaker cables.
For situations where these parameters have a negligible impact on actual performance, eg: typical line level connections - there would be little noticeable impact (it might be measurable, but very very low level) - and most likely swamped by other aspects of performance pertinent to the components at either end.
If we are talking about phono interconnect, ie: the cable that goes from cartridge to phono stage, and the cartridge is a high inductance cartridge (MM / MI or similar) - then the difference could be huge, as you would likely be doubling the capacitance of the cable, and that will directly impact the frequency response from around 3kHz up.... difference would be highly audible, no "golden ears" needed.
In this latter situation the cable capacitance, the resistive load and the cartridge inductance form an Equalisation network / filter - if you change the parameters it has quite a dramatic impact.
It's not good practice to use missmatched cables... but in many cases it can be lived with.