Audiophiles can't distinguish audio sent through copper, banana or mud

Music lovers buy audio equipment to listen to their music.

Audiophiles buy music to listen to their audio equipment.

The problems are multiple;

1. When you move out of the sweet spot to listen anywhere else in the room, the music becomes distorted because you can are now hearing an EQ curve that is compensating for the sweet spot, but has nothing to do with the frequency response in the other listening positions.

2. These automatic systems tend to apply dozens of small EQ bands to the output, which smears the phase relationships of the record and dulls transient response. The feeling is of the record being mushy and dull.

3. These systems cannot account for time-domain ringing issues in the listening room. So a corrective EQ boost to compensate for a dip in the sweet spot will become a loud ringing at that frequency elsewhere in the room.

4. Corrective EQ cannot compensate for the deepest frequency nulls, no matter how much of a compensatory boost you make. A heavy handed boost to compensate this way will cause massive ringing elsewhere in the room.

I could go on.

These automatic room correction devices cause far more problems than they solve. There are ways to apply some EQ correction, but you will get 10x larger returns on performance by addressing acoustic issues introduced by the room, rather than trying to compensate on the speaker outputs.

Source: I design and build high-end recording studios for working audio professionals and tune speaker rigs for Grammy-winning artists.

I think people overlook how artificial records are. Even the ones that are ostensibly "natural". Records are "hyper real" in that they are usually crafted to give you an ideal perspective of the entire ensemble. In a sense you can hear "everything" or at least hear everything perfectly balanced and crafted with intention. This could be as simple as dynamic control (compression), artificial spaces (reverb), and distortion or saturation that the average listener will interpret as "natural". In that sense it's an illusion.

Again, this is okay.

Even classical records, which often strive for naturalism use these tools to sculpt the record. Even when they do not employ these techniques I've still never heard a classical record that sounds as good as sitting in a hall in front of a world class orchestra. It's unreal how vivid the sound is when you're in the room with the orchestra. It's breathtaking and something that everyone should aspire to experience at least once.

The chosen propagation media (wire substitute) wouldn't have significant frequency responses differences for those lengths for that level of power in the audio frequency range.

You'd need to have transmission-line effects kick-in which would occur at higher frequencies and/or if a cross-section of the signal propagation paths would have a significant difference in impedance. All three of the chosen medium act like simple power-sink resistors in this scenario--attenuating the signal consistently across the power frequency spectra.

Seriously, just do a frequency sweep and plot the log of the output responses! But no, that would be far too straightforward an experiment.

What really matters is the signal source, any amplified distortion in the signal, final sonic transducer (speaker), transmission medium (air density), transducer orientation (for higher frequencies), and the individual listener's ear.