BD37513FS, BD37514FS, BD37515FS are sound processors built-in 2-band equalizer for car audio. The functions are stereo 4ch input selector, input-gain control, main volume, loudness, 5ch fader volume (About BD37513FS, 4ch fader volume are available). Moreover, “Advanced switch circuit”, that is ROHM original technology, can reduce various switching noise (ex. No-signal, low frequency likes 20Hz & large signal inputs). “Advanced switch” makes control of microcomputer easier, and can construct high quality car audio system.