Yes and No...It depends...
If 2 sounds are lined up exactly then triggering them simultaniously
won't cause a phasing effect (Actually it does but then it's a static phase)
If you want 2 kicks on top of eachother the you don't want the energy
sucked out because the low frequency content of the kicks cancels
eachother out....so if you want the punch of one kick and the big boom
of the other there really is no other option than to isolate both pieces of
frequency domain, either by EQ (which is not so favorable) or to actually
cut parts of the sample in a sample editor (best done one a computer
because you need the screen resolution)
Then glue the punch part and the booom part together and voila! But keep
in mind that upgoing waveform must be lined up to upgoing waveform to
avoid clicks or midrange distortion that makes to kick wobbly...this is
something you don't want...
Peace!
MPC4000 - Alesis Andromeda - Nordrack II - Jupter-6 - Virus B - Pulse - JV-1080 - G4 1.25 MDD - TR-909 - TB-303....And some more tools to get the job done!