Find the right bass sound. If you have a sampler, you can find sub bass samples online. One reliable and classic sub bass sound is in the 808 drum machine, which is so popular that many people have uploaded the individual drum sounds online as audio files. If you are using a synthesizer or drum machine, browse the different tones until you find the bass sound that you want.
Attach a drum pad or trigger. If you want a drummer to trigger the bass drop, he can do it most easily with a drum pad or trigger. These can be attached to the kit itself or sit on the floor as drum pedals. Connect the trigger to your drum machine, synthesizer or sampler. Another musician, such as a keyboardist, can trigger the bass drop through a MIDI controller keyboard or by pressing the corresponding pad on a sampler.
Connect the sound generator, whether it's a synthesizer, drum machine or sampler, to a bass amp, which should then be connected to a PA system via the amp's direct-out jack.