I use 'em.
Ain't no magic to 'em at all. It takes one signal and splits it into two paths.
I use mine between the preamp and the power amp to drive a subwoofer. No problems.
Some use 'em to take one LFE output and send itto two subs. Again, no problem.
Others use 'em to split the LFE signal to both the right and left inputs of a sub. Guess what? Yep, no problem.
No need for fancy stuff. I use the stuff fromthe local RatShack but if I really wanted to save a few pennies, I'd go on the net. But, I wanted them NOW!
One caution.. .don't use 'em in the other direction. You don't want to combine two signals into one. Trust me on this...