I'm need to purchase a center channel speaker.
I'm considering the CBM-170 SE or CMT-340 SE.
My current L/R speakers are the older (4 years) CBM-170's and not the SE model.
I'd like to select a matching center to go into the center cabinet below the TV.
On my HK AVR 75 reciever I've selected the small front speakers mode which has a crossover set at 100hz (i can't adjust to 80hz).

My concerns are ...

How does the CBM-170 SE differ from the CBM-170 ?

The CMT-340 SE seems to be 1db more efficient than CBM-170 SE, does this mean the CBM-170 SE will match more closely ?

The CMT-340 SE has a lower response but with a crossover setting of 100hz which I believe applies to the center channel as well as L/R is there any benefit of more costly CMT-340 SE ?

The CMT-340 SE and CBM-170 SE seem to have identical components with the exception of an extra woofer. Are the crossover points and rear port tuned differently ?


What sound levels and frequencies does the CMT-340 SE and CBM-170 SE achieve with the rear port ?

Also with the location of the speaker on a cabinet shelf what sound energy and frequencies are lost if the port energy goes into an infinite baffle (the space behind the cabinet shelf) ?
(the point is that there is no pressure loading on the driver in that there is plenty of air space behind the speaker but I expect very little of the sound to be returned to the room hence the term infinite baffle).

thx, jronne