Outlaw ICBM hurt my 2-channel?

If your Bach's don't have any base, you should try checking your seating and speaker placments! You'll likely find that if there's not good bass from the speakers played full range(or even as small often), it's because you need to move things. The Speakers, or your listening possitions(or both) aren't coupling well at certain frequencies were they are.
Still, bass mangagement could be helping, depending on a lot of factors. I would concentrate on getting the mains set up for "full range" play(assuming you want to play em full range, and "filter free" possibly for 2 channel music dubties if you can), so they sound even and strong on their own*(relatively)..at least approaching flat frequency response. If you do this, your 2 channel music will have excellent potential(considering other acoustics).
You can still play the sub "in parallel" with the mains playing full range from your pre amp/amp set up, considering most moderate music choices. For the HT, hard rock, techno, and other heavy dynamic stuff however, bass management is going to be a must for best performance! In this case, I'd just run your mains as "small" looped through your "line-1" preamp from your digital pre/pro(you do have this, right?), and let the sub play from the "sub-out", playing the bass. So, you'd basically be using your DD/DTS pre/pro for HT/rock/heavy dynamic stuff, setting speakers to "small", and sub handles the bass. Then, for more pure music dubties, you can just bypass the pre/pro, and do full range for the Bach's, and let the sub play "in parallel. Infact, you can use the RCA connection on the sub from your DD/DTS pre/pro, and use "speaker level" connections for your music chores when played "in parallel"! This might be a bit tricky, but workable for excellent results if done right.
HOpe this helps

Based on my experience with mine, I would say that the real, but extremely minor, degradation of detail and added noise is completely worth the absolute transformation of your system's low end capability.

Reworded: You would be trading an amount of detail that you could concievablely not even notice is missing for the difference in bass performance between your mains (bookshelf/monitor, right?) and your subwoofer. Odds are this difference is HUGE.

It was a no brainer for me, but to each his own.

Thanks for the responses guys.

foreverhifi: I listen mainly to rock and I bought the pre with hopes of better sound. If I understand you're scenario, for 85% of my music listening I would be using my Yamaha receiver and amp. This is what I'm trying to get away from by picking up the preamp. Rock may not be as "pure" and "clean" as some other types of music, but it's what I listen to and it's the type of music I'm trying to make sound the best. I've put a fair amount of effort into dialing in the Bachs as best as the room and environment will allow. I went from everything < 90 Hz being handled by a pair of 12" woofers to a pair of 7" in the bachs. I miss the slam. I'm curious about your configuration option when you talk about bypassing the pre/pro and running the sub in parallel. If I bypass the processor how can I run the sub in parallel? If by using "speaker level" connections, you mean the speaker level connections found on the back of some subs, mine does not have them. If you have another configuration option in mind I'm anxious to hear about it.

Johnathanb: These are smaller 2way floor standers.

I'm content with the speakers I have and changing them is not an option right now.