Subwoofer crossovers


I want to use my 2 JL113's with my 2 channel as well as my surround sound system. The JL's do not have an LFE input only L&R inputs. I think I need a crossover for the 2 channel system that I can shut down via remote so only the setting in the surround sound processor control the sub in theater mode. I use the right inputs for 2 channel stereo & the left inputs in a T configuration for mono with the surround system but the settings for 2 channel restrict the sub too much I think. I would like two differant crossover settings.
Any ideas or am I making this harder than it is.
Thanks for your input.
hevac1
Hevac, the LFE channel on the NHT is summed to the stereo channels. It does not override it. Works like a charm. It was the only device I could find that could so this. Marchand offered to custom build me a 3 in 2 out Xover for a lot more money. Unfortunately NHT no longer makes the x2 but they show up used occasionally.
Re:

Marchand x-over. I just want to clarify my experience. I bought a used Marchand that had been re-tubed by the dealer, but it was still noisy. I returned it and bought an X2 for interim use while I decided how to proceed with a permanent x-over solution. The X2 turned out to be good enough to keep - so I did.

However, this shouldn't be taken as a thumbs down on the Marchand. It's entirely posible (maybe even likely) that the issues I had were with that particular unit, especially given that it was used.

I don't think anyone should extend my experience with that unit to an evaluation of that model. I certainly don't.

Marty
For a two way X-over at low cross-over point tubes would probably not be your best bet. I was considering a custome made (i.e. LFE channel added) version of the (cheaper) XM-44.
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Sure, but to suggest Hevac should cut off his $40,000 speakers with 11" woofers at 80Hz and reproduce this range with two EQ'ed subs instead makes no sense. Now, if you believe a sub / satellite system has big inherent advantages that is a different discussion. But once you have sunk a lot of cash in a full range speaker, you might as well use it. Keep in mind that going up the foodchain in a speaker lineup usually involves getting bigger cabinets and woofers. If you opt for a sub / satellite configuration, get a cheaper model and deploy the savings towards subs.