is it good to bi-wire or bi-amp a sub, i have a subwoofer box that alows this, but is it good to do?
Its a Alpine Type R the 2 Ohm one
Sub model Alpine SWR-1222D and amp is Alpine MRD-M605
Is your amp 1 ohm stable?
if it's a single sub, the only way you can wire the sub is in series giving the amp a 4 ohm load. if you had the dual 4 ohm coil sub, then you could wire it in parallel and give the amp a 2 ohm load.
how would i do this? and will it be benificial?
check my sticky, it should have series and parallel wiring. and yes it's going to be beneficial for you to wire your sub @ 4 ohm so you don't cook your amp!
why would i cook my amp, its fully capable to handle a 2 ohm load?
Your amp is stable for a 2 ohm load. Only way you can wire your sub is 4 ohm or 1 ohm.