Yes the NHT has speaker level inputs. As do the ML subs.
Many integrated amps do have preamp outputs including the NAD. The C320 uses it to feed the amplifier main input which could be split via a hard-Y but the extra cabling $$$ would dictate simply purchasing a better integrated.
I think the answer to your situation is a high output sub (like the NHT that is for sale here on Audiogon). THe NHT uses an external controler that can be placed in the same rack as the NAD. It also uses it's own DIN type interconnect to feed the sub.
Good luck!
Many integrated amps do have preamp outputs including the NAD. The C320 uses it to feed the amplifier main input which could be split via a hard-Y but the extra cabling $$$ would dictate simply purchasing a better integrated.
I think the answer to your situation is a high output sub (like the NHT that is for sale here on Audiogon). THe NHT uses an external controler that can be placed in the same rack as the NAD. It also uses it's own DIN type interconnect to feed the sub.
Good luck!