Hello all
and happy holidays
 When I play TTS everything is fine when I play the soft synth like DP, Rapture, Z3ta 1 or 2 they will not play anything below C2 on the bass why is this? Again if play in on TTS everything plays fine. One thing I do is on the MIDI track is bring the key up to 12 then on the synth bring transpose down -12 it works for some. Usually I have to do some tweaking or I may just not transpose the synth down.
Thanks Red4Con1

As a rule a GM synth will have most of its patches show an extended range. Where most non GM synths often have a pitch range that is the same as the real instrument. Synths that rely on samples are often the ones with the least pitch range. 

Thanks John for clearing that up.

When it comes to sfz engine synths like DPro and Rapture it is possible to extend the notes played by a program by modifying the sfz files the program loads. This is done by editing the sfz files which are text files.

Thanks Scook I'll give that a try.