making a loop without setting the bpm

is it possible to record an audio loop without having to set the reference tempo before?
I mean, as you would do on a loop pedal?

Which MPC?

MPC Live mk1

There's a few areas where I'm not sure how to answer because I'm not sure what you're trying to do... but here goes...

If you're just trying to record a tone or pad or something that is non rhythmic... then you can just go into the sampler, record the content, and then in the sample editor you can adjust the start/loop/end points to get something that you could sustain as a sound, or loop indefinitely.

If on the other hand you're trying to loop a melody, chord progression, drum loop, or whatever... you really need to have the tempo set, record into the looper, and play to the tempo. The MPC doesn't have a loop pedal mode where you can freely punch in and out, or set a tempo based on the loop in realtime.

Can you explain a bit more what it is you're looking to do? One of us here might be able to give some better suggestions.