Like all pressure-gradient cardioid microphones, the Audix OM-3xb exhibits a proximity effect when used close up, so the bass response has been rolled off to partially compensate. Used very close to the mouth, the mic still demonstrates a noticeable bass rise with a response extending below 40Hz, whereas using it at a distance of half a metre or so leads to a degree of bass cut. By changing the mic to source distance, a useful amount of tonal change can be brought about without having to resort to external EQ. Mind you, this is true of virtually all dynamic cardioids and hypercardioids, but it's a point worth making nonetheless.
