Re: Crossing over htm200se w/o a 2.1 receiver
I think it would probably be ok using the controls on a sub (maybe one of the smaller Rythmiks) to integrate with the HTM200's. I'd try that first before investing in another receiver/preamp.
Depending on budget, if you decide you need another receiver/preamp, might want to look at a miniDSP (e.g. the Flex) to use as a x-over and bass management/eq. I did this with my dual E15s and ELX RAAL Towers for my 2 channel system although the system was pretty good without the Flex (but a little bass heavy at times, which you'll likely not have with the HTMs). The other reason I added the Flex was that I could set up 4 different profiles for music -- 2.1, 2.1 with house curve, 2.0 with bass EQ (so I could use the Towers by themselves), and 2.0 w/o any EQ.
* LG OLED65E6P, BenqHT2050A
* Anthem AVM90, Rogue ST100, VTV Pascal 7 ch
* Sierra Towers/Horizon (all ELX RAAL), S2EXv2 surrounds, HTM200SEx4 heights, Rythmik E15HPx2
* VPI Classic 1+ (VTA & Fatboy Gimbal), PE Eagle/RR, VAS NOVA, Soundsmith Paua, Manley Chinook, Bob's Devices SUT, SugarCube 1 mini
* Oppo 203 & 103D, EverSolo DMP-A6
* miniDSP Flex, Audiosensibility & Blue Jeans cables, Symposium & Isoacoustics, GIK
* For RDJ: Anthem MRX720, Sierra LX, Luna Duo v2 center, CXNv2, TBD