Emu XL-7 & MP-7 User's Group

hello yall
 i am having trouble controling my akai mpc with my mp7.
 the midi does not stay on one channel and when i am programming the 
mpc from the mp7 .
 for example if i program drums via midi on tracks 1 to 4 it will be 
fine . i have to turn down the volume of the mp7 tracks because they 
will play along with the midi tracks. after i am done laying drums 
and i want to put in some bass only on a non midi channel using only 
sounds from mp7, the mpc still plays on that track.
 how can i turn midi on and off and assign it where i like and  keep 
the rest untouched.
 i want midi on tracks 1 through 6 and the rest sounds from the mp7.
 arrggggg.. this is frustrating, i know im not a midi captain but i 
cant seem to get it . any help would be cool yall.
 thanks