Fathom 113 no highpass filter

Sorry, I meant low cut the mains.

IMHO, I would bypass the built-in crossovers (and I do) in order to have a more definite and controllable relationship between the subs and the main speakers as will be supplied by a good external crossover. It can be independent or built into a good processor.

Kal

Thanks guys,the fog has lifted somewhat,Kal your right as I use a Arcam AV-8 for movies and I use the arcam's X-over instead of the other JL's(4) which also go thru the 50a's.
For some reason I keep thinking I can't use an ext X-over with the 50a's,the subs have them(which two of them I bypass for movies,my AV-8 has the crossover for movies.You guys are right as I'd just use an ext x-over for the other two subs for the music end of it.
WTF,don't know why I couldn't see that before,to much gear perhaps,Thanks guys.

I agree with Marty's response completely. I'm using the F113 with my B&W 800's running full range. One other reason to do this is that by by-passing the internal crossover, the signal path has less connections and less to corrupt the mid's and high's going to your main speakers. My speakers are considered full-range and, therefore, I set the subwoofer crossover at around 50-55 hz. It integrates really well.