has designed and built his own cross-connect coax cables and documented the process here: Cross-Connected Coax Speaker Cables
Maybe he can comment on this some more, especially for those of us with no crossovers in the ESL path.
I've used several different DIY cables, including the very expensive cross-connected, Teflon jacketed coax cables recommended by Jon Risch.
My experiences may differ from that of Martin Logan owners because my homebuilt ESLs use a different (resistor-segmented) panel design which is an easier, more resistive load for the amplifier. Hence; mine are less reactive to cable variables.
A conventional ESL (ML) is sensitive to cable configurations because even a small increase in the cable inductance adds to the transformer’s leakage inductance, which then affects an ESL’s characteristic high frequency response peak and coincident impedance minimum. This is why
Roger Sanders recommends cables with minimal inductance, like the ones he sells.
A cable can be configured for minimal inductance by weaving the conductors, or for minimal capacitance by separating the conductors, but you can't have both in the same cable. Physics says that inductance and capacitance are "conjugate variables" (reducing one variable increases the other proportionally, and visa-versa).
Speaker cables will have some combination of inductance/capacitance plus resistance, but the mix can be tailored by the configuration.
According to the cross-connected coax cable's designer, Jon Risch:
“Cross-connection is used to reduce the inductance to an absolute minimum. Merely paralleling the center wire and shield would create two separated different polarity composite conductors with an inductance much higher than the cross-connected pair.”
I wouldn't know how to verify Risch's claim. What I can say is that my system sounded great using the cross-connected coax cables.
Previously, I was using DIY cables made from Mogami coax (not cross connected) with the stranded, spiral wound shield conductor, which I believe is the same cable used in the ESL-specific cables sold by Roger Sanders' company, Inner Sound. My system sounded great with those cables too.
I recently moved my speakers farther apart so I needed longer cables. Rather than building another set of $$ Risch cables, I opted for cheaper 12AWG Blue Jeans cable, and my system sounds great with these too.
As I noted earlier, my homebuilt ESL is an easier load to drive than a Martin Logan, but I honestly don’t know that I could tell any of these cables apart in a blind listening test, even if I could switch between them rapidly, which I’m not setup to do.
Intellectually, I know that the Mogami cables would have very low inductance and high capacitance. Whereas the cross connected coax cables are claimed to have very low inductance and moderate capacitance, and the Blue Jeans cable is probably somewhere in the middle-- but I'm not hearing a difference with my speakers.
I’ve always believed that high dollar cables offer no discernable benefit over similar gauge lamp cord. I just like tinkering and building things, and the cross connected cables tweaked my curiosity so I built them.
My advice is to invest in what makes a difference first (speakers & amps), and then play with cables if you want to-- but use 12AWG minimum wire size. And if you're worried about cable types; avoid ulta-low capacitance cables (like ribbon cables) for your Martin Logan ESLs, as these would have very high inductance.