The AT3525 is a medium/large-diaphragm, back-electret microphone with a fixed-cardioid polar pattern, switchable 10dB pad and switchable 80Hz, 12dB/octave high-pass filter. Both switches are recessed and located on the underside of the mic rather than on the side, as would be more usual. The capsule employs a very thin diaphragm with a gold surface layer, suspended above a precision-milled backplate, and artificial ageing is used to stabilise the capsule performance. The output from the mic is on a conventionally wired balanced XLR with gold-plated pins, and a sturdy shock-mount is included, along with a soft, zip-up case. Full 48V phantom power is required (+/- 4 V).
One of the AT3525's claims to fame is that it can handle very high SPLs, up to 156dB with the pad switched in (1% distortion at this level), so it can be used in virtually any environment, including in close proximity to drums and other loud percussion. Predictably, this reduces its sensitivity slightly when compared to other typical large-diaphragm mics (-48dB (3.9mV) ref 1V at 1 Pa), but it's still sensitive enough for most typical studio instrument and vocal recording applications. The useful frequency response extends from 30Hz to 20kHz, and the included plot shows a nominally flat response up to 2kHz, followed by a wide presence rise, maxing out at around 4dB before dropping off again at around 12kHz.
