I always go by a basic formula for beatmapping samples by notes.
32 divided by 4 (quarter notes)=8 bars
32 divided by 8(eigth notes)= 4 bars
32 divided by 16 (sixteenth notes)=2 bars
verses the 1k or 25k`s
64 divided by 4 (quarter notes)= 16 bars
64 divided by 8 (eighth notes)= 8 bars
64 divided by 16 (sixteeth notes)= 4 bars
Depending on the loop either drums-16th notes, bass or beatmapping quarter to eigth notes. Though eigth tends to be the best for me for tempo changing basslines and full instruments.
The norm for using loops with varying tempos aka human drummers tends to be 4 and 8 bars. But at least for me the tempo varies can be alot especially over 8 bars or even 2bars so I rarely use a 16 bar loop. I would split it into two 8 bars and work from there.
Everyone can do it on the 4k just one has to take the extra step. I sold my baby 2500 aka 1k with the 64 regions in order to have a more software based studio.
It is all about the techniques for beatmapping chop small and use small loops, regions or measure however you want to call it.
P.S. if you are working with a sequencer based loop no need to worry about beatmapping so much just match your sequencer with the loop.
