Adding a sub - what will I loose?

Well Al and Irv, I suppose I should be embarrassed by your uncovering what I didn't know about subs being driven by speaker-level inputs, but in fact I learned something. Thanks.

Johnny, I certainly agree with your point about needing tight control of cone excursion; I'm skeptical about your rise time argument.

On a personal note, I use a pair of Velodyne HGS-15s controlled by a VMS-1 bass manager. The subs blend seamlessly with my KEF Reference 104/2s. I was attracted by Velodyne's high-gain servo and powerful amp, which hold promise for matching cone excursion to electrical input.

Has anyone experimented with using standard RCA cables with Y-adapter vs. using a Y-cable? I only see the real cheap generic Y-cables available as most cable companies don't make the latter.

Seems like the using a cheap $5 Y-adaptor on any cable will pick up noise...no matter how expensive the cable.

Johnny53, you brought up a good point about room acoustics. I have some room treatment on the walls, corner traps and bass traps. All DIY stuff but it works. The bass traps made a huge improvement when I had full range speakers.

On the question of "fast" bass, this strikes me as an excellent article:

http://www.soundstage.com/maxdb/maxdb061999.htm

Best regards,
-- Al

>>12-03-11: Tghooper
Has anyone experimented with using standard RCA cables<<

If we apply the soundsreally rationale, you'll need a pair of $25K interconnects.

:-)