Where are the passive subs?


I can't seem to find a passive sub. They all have those Class D amps in them. I don't want to pay for an amp I don't need.
Also, these powered amps appear to have speaker terminals. 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?

Any ideas?
rail2rail
Post removed 
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
 
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!