Is there a better sub-cable?

there is always something better out there. but i wouldn't worry to much about the sub cable. (i'll probably catch hell for saying this) but the subwoofer only carries low frequency effect sounds. Unlike mains or surrounds which have to carry more than just LFE.

I use a 20' IXOS cable.. ran about $50

Chris brings up a good point. make sure it's sheilded.. or it could get a hum in it.. or even pick up radio signals or ham radio too. most decent sub cables are sheilded anyway..

coax based interconnects aren't the best for caring audio due to the timing differences between conductors.

unbalanced interconects based on coaxial designs(or home made)cause far more problems then they attempt to solve.The Negitive shield conductor has 20 to 30 times more surface area than the center positive conductor.This Mechnical difference causes 100-250 DC milli-volt differences from transmitting end to receiving end which DISTORTS the orignal signals proper balance.

If you feel the need or have to use a coax base design cable for any type of line level signal, then use a rg59 based design.Also make sure it's cooper.

I have made thousands of digital cables,Analog interconnects,sub cables, and video wires out of rg6 quad,rg6,and rg59sd I have found that the 59 works the best overall.
Analog audio suffers the most with smeared highs.It's in the coax design that causes this.The outer shield is the most significant reason why the capacitance and inductance of a coax is high and hard to reduce.The delay of a coax cable due to capacitance and inductance is a factor in the poor high frequency response.Another reason for not using this cable for an interconnect due to poor performance is the distortion of the orignal signals exactly Orthogonal electrical fields.

DO what you will with the wiring of your systems.I don't believe in substituting different design cables for different uses other then what they where orginally designed for.Just like the hype of using cat 5 for speaker wire.......give it a try,forget about all the tech O babble for a minute,it sounds like ****.......after you listen and determine that it sounds like ****,then go and research your face off WHY.......

I'll go as far as telling you from years of experience making cables and having times to substitute coax for interconnects,it's works.......but not well.Same goes for cat 5...it will work,it gets something of the orginal signal there, but something is lost or added along the way.......listen and you'll see .