Where are the passive subs?

A currently produced high quality passive sub I am aware of is the Daedalus BOW.  However it is definitely not inexpensive, and it has presumably been designed with the expectation that it would be used with Daedalus speakers.

Regards,
-- Al
 

The last passives I heard of were the HSU's of the 90's.

OK, so I'm not insane. This seems like a gap to me. It's been a LONG time since I have considered a sub, so had to catch up. I don't need one, per se, but it would be fun. Well, unless they pick the amp for me, make it Class D, and stick it in the box!

Does that mean even if I go with a sub that has an amp, I can bypass the amp using the speaker terminals, or is that some form of input to the amp? 

the terminals are high level inputs which you connect to your stereo amp.
It doesnt bypass the sub amp. but you could always change the sub amp or convert to passive.

I dont know how much EQ if any is applied to these active subs. If the response is equalised then you cant remove the class d amp and connect a different amp and expect the same response.

If your main focus is music, check out the 15" Tannoy Sub 15i. It's not great for home theater, but for music it's one of the best I've heard, and not too expensive.