If you’re looking to enhance the low end of a djembe on your next recording, try this technique that microphone maven Karl Winkler shared with me. The idea is to emulate a boundary microphone setup with a quality omnidirectional small-diaphragm condenser to achieve amazing low-frequency results. This approach works really well with hand drums, such as a djembe, but you could certainly use it for bass drums or anything else with low bass.
Why an omnidirectional mike and a boundary setup? A true omnidirectional microphone will not exhibit coloration from proximity effect (a low-end boost at close distances and loss at further distances when using a directional microphone) and is capable of capturing extended lows despite being at a distance from the sound source. With a boundary microphone, there are no nearby reflections to combine with the direct signal to cause phase cancellation, so you get a more natural sound.
The low-frequency response is limited by the size of the boundary, so this setup would work best on an uncarpeted floor. In addition to a close mike on the drum itself, select for the boundary application a small diaphragm condenser microphone with an omnidirecitonal pickup pattern, such as a Neumann KM183, Audio-Technica AT3032 or AT4049A, or an Oktava MC012 with an omni capsule in place (just to name a few).
A simple business card torn in two can be used for the resting mount. Place the two pieces with their edges parallel and spaced so that the microphone capsule can be suspended over the gap directly above and extremely close to the floor. Rest the flat address end of the mike on the edges, and gaff tape the microphone cable to the floor to support the stance of the mike (Fig A).
The distance you place the mike from the drum depends on the sound you want, but start by positioning the setup a few feet away from the drum and experiment a bit by moving it farther or closer until you get the sound you want. Some drums (like a large djembe) will produce huge low-frequency fundamentals, so listen to find the perfect position to best enhance the lows without overdoing it.