That is, unless you use M series Monster cables. As I gradually moved away from analog audio equipment over the years, I retired my (pricey) M series audio interconnects to the parts box. Later, when I'd misplaced a coax I needed, on a hunch I looked at the mess of L/R audio cables, and they are, indeed, 75 ohm coax construction.

This may be true of other expensive cables, if you can see there is an insulator around the center pin (plastic ring, vs. all metal connection), it's probably coaxial construction.