Everyone had probably seen the Yamaha NS10’s driver (the popular white cone speaker), mounted on a stand in front of a bass drum head. Many engineers tried this trick, and it worked so well that Yamaha decided to release a product based on it; called SubKick. The concept is very simple; they just added a drum-like housing for the driver and redesigned the electronics as a ready-to-go solution. But what is the concept behind it? Even a large diaphragm condenser microphone has a relatively small capsule to capture all bottom end frequencies produced by the kick drum. Using a speaker cone introduces some wiring complications, but it’s not rocket science since the electronic principal of dynamic microphone is pretty similar to a speaker cone, it just works another way around. You end up with a very large diaphragm dynamic microphone. I’m not going to describe all the technicalities and physics concepts behind it, just remember, that using a speaker cone as a microphone requires impedance balancing, which is done pretty easily by using a DI (Direct box).