A sound pickup device, which is arranged in proximity to a percussion
instrument (e.g., a bass drum), comprises a diaphragm stretched under
tension over an opening of a shell having a cylindrical shape, and an
electroacoustic transducer arranged inside of the shell. The
electroacoustic transducer comprises a magnetic transducer or a speaker
unit. Herein, the percussion instrument is played to produce the
low-pitch sound, which is transmitted to the diaphragm to vibrate so that
the electroacoustic transducer is activated to convert the low-pitch
sound into an electric signal, based on which the low-pitch sound is
reproduced by a sound system with a high fidelity to the original sound.