Need help understanding signal to subwoofer

I have a CJ 2 channel system in which I incorporate HT with a HT receiver connected through the 2 ch pre via video loop. The HT receiver powers the center and rear channels. The CJ powers the fronts. If I connect a subwoofer to the CJ via low level inputs, how much bass information (if any) will I be losing in the HT mode?

I know the REL and ACI Titan have connections for simultaneous running of LFE from processor and line connections for 2 channel. However I am toying with getting something smaller ie Sunfire or B&W 2500. These can only be connected to 1 source (I think) Therefore the question about information loss to HT. About 75% of my time is spent in music, but I do want the use of the sub with movies without having to change connections. I also do not want to have the HT processor on to listen to 2 channel. If there is a way to connect these subs and get the best of both worlds, please let me know? Here's a link to my system.

As always, Thanks for your help
There is a substantial amount of information that would be lost if the sub was not hooked up to the HT. The entire LFE (Low Frequency Effects) channel would be lost (the .1 in 5.1)
If physical size is a consideration how about the REL Q201 ?
I think it's about a 1 foot cube, but has all the features of the bigger RELs. I've not heard it but all who have seem to like it.
If your use would be 75% music and 25 percent HT then I would suggest using a REL subwoofer as you mentioned. I have used the LFE connection for HT and the direct speaker output connection for music. My suggestion is to find the space to place a Storm III or a Strata III. You will not regret the purchase. I owned two different Sunfire models and found that they were great for home theatre but did not integrate well with my speakers in two channel stereo. The B&W Subwoofer did not integrate as well with my speakers as did the REL, my main speakers are B&W N803's.
Swampwalker> This has been my thinking as well, however I have also been advised to connect to CJ and then set processor to large front speakers and the rest small. Set sub as no or equivilent and then all bass will go to fronts and thus to sub. Does this seem right? It does to me but then again your point about the 5:1 makes sense also. Is this a workable compromise?
Artemus, recently I've been looking at subs. I took a look at the Martin logan page. The new Descent sub. I opened the manual on descent and it showed the descent being hooked up as 2channel, ht and both at the same time. From what I read it looks like the descent will take both connections at the same time, giving you both ht and 2 ch.. The sub has 3-10 in subs and a 400 watt amp. Abit pricey @ $2,400. I never auditioned it, but if you do a search here I think you'll find someone who ownes one. Good luck, pete