Kumu bass drum SideHoles have turned out to work very well in practice. The solid resonant head offers lots of extra sound and bottom end, plus the drum looks better. However, the playing feel of a bass drum equipped with the SideHole differs from a drum with a perforated front head – there is a bit of rebound when playing the kick. The SideHole, which is in the shell, doesn’t let the air escape from the drum like a resonant head with a hole in it. In order to minimize the rebound, Kumu bass drums feature small vents next to the tuning rods, thus making the rebound almost non-existent.
I’ve noticed that drummers react to the rebound in three ways: the first guy doesn’t pay any attention to it at all, the second takes advantage of it and the third one finds it a nuisance. If you’re used to “burying” the beater, meaning that you leave the beater on the drum head when playing, the rebound might feel awkward. However, by altering the tuning just a bit, things can be changed. On the other hand, if you’ve learned the technique of letting the beater bounce off the drumhead, the sound is really big and you can take advantage of the resonance of the head. And hey: a number of guys have learned the new technique very easily – the best I’ve heard is that one drummer did it in just two nights.
The feel of the kick drum is largely affected by the pedal and the beater you’re using. Some pedals react more sensitively to the rebound, others kind of eliminate it. Furthermore, the sound coming from the drum can change quite a lot with different pedals.