MPC Live Looping Question

I have four Volca's(which are controlled by a Beatstep Pro) plugged into a mixer with the output going into the MPC LIVE 2. I am trying to use the looper on the MPC to record a short phrase but if I have overdub on it continually increases in volume every time the loop wraps around. How do I prevent this so that it's only overdubbing new notes and not increasing the output of what was previously played?

I feel like you kind of answered your own question... but...

You only want to overdub new notes. Otherwise you will get the effect with any looper of your choice that if you overdub, it will continue to get louder over time. Fundamentally though, you should consider your Volcas as loopers... they are already looping... and you really just want to record specific new content to the looper.

My suggestion would be to tell us what outcome you want... it will make it much easier for us to give you one or more suggestions for how to set it up.