You're welcome! 75W into an 8 ohm speaker would be only 24Vrms or 35Vpeak.
By "dc" CPK meant "dielectric constant," which is proportional to the capacitance the cable will have, and the amount of "dielectric absorption." Thicker insulation will also increase capacitance, everything else being equal, and thinner insulation will reduce it.
My own feeling is that as long as it is within reasonable limits capacitance in an 8 foot speaker cable is not especially critical. It would be more important in an interconnect cable, because of the much higher output impedance of the component driving the cable. The opinions of others may differ on this, and I readily acknowledge that other factors, known or unknown, might in some systems make capacitance more important than I am envisioning.
Enjoy your project!
Regards,
-- Al
By "dc" CPK meant "dielectric constant," which is proportional to the capacitance the cable will have, and the amount of "dielectric absorption." Thicker insulation will also increase capacitance, everything else being equal, and thinner insulation will reduce it.
My own feeling is that as long as it is within reasonable limits capacitance in an 8 foot speaker cable is not especially critical. It would be more important in an interconnect cable, because of the much higher output impedance of the component driving the cable. The opinions of others may differ on this, and I readily acknowledge that other factors, known or unknown, might in some systems make capacitance more important than I am envisioning.
Enjoy your project!
Regards,
-- Al