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Different from most headset mics, the A-T BP894's cardioid capsule is at a right angle to the boom.
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The Audio-Technica BP894 MicroSet Cardioid Condenser Headworn Microphone was first seen at the AES Show in New York City in mid-October 2013.
A headset that comfortably and unobtrusively fits and stays in place, while performing its role as an accurate audio transducer that is true to its source, is always welcome. At first glance, Audio-Technica's newly introduced BP894 MicroSet Cardioid Condenser Headworn Microphone looks like a contender to enter the elite ranks of professional-quality headsets.
The heart of the headset is its miniature mic capsule, with a diameter of 2.8 mm, with a cardioid polar pattern for greater noise and feedback rejection at the rear of the mic. The mic capsule is contained within a small rotating housing at the end of the mic boom, allowing the active side to be precisely positioned toward the corner of the mouth. Different than most headsets where the capsule comes right off the side of the boom, A-T placed it at a right angle to the boom so that it has a T-shaped profile. To aid the positioning process, a small dot on the housing – designated a “talk-side indicator” in the data sheet – is designed to be aimed toward the audio source.
Frequency response for the microphone is stated as 20 Hz to 20 kHz, and the supplied response curve shows the nearfield (at a distance of 2 – 3 cm) reproduction is flat within a dB or two between 20 Hz and 2 kHz, with a gradual rise to about +6 dB at 7 kHz and then a gradual rolloff that crosses 0 dB at around 15 kHz; response is down about 5 dB at 20 kHz. I expect that the resulting audio will sound quite natural through the fundamentals, with good presence and articulation and some “air” on the top. The polar plots show a fairly wide cardioid pattern that seem consistent across all measured frequencies (curves from 200 Hz to 8 kHz were supplied) up to 60 degrees off-axis, with the deepest nulls at about 130 degrees off axis. Rear rejection is a bit over 10 dB at 200 Hz, and 15 dB or more at the higher frequencies. The mic is fairly sensitive at -49 dB, and has a typical dynamic range of 104 dB. Maximum input sound level before audible distortion is 135 dB SPL.
The microphone is a condenser, and requires phantom power between 11V and 52V from the mixing board. When used with a wireless bodypack, it requires 2.5V to 11V. A barrel-shaped XLR adapter is supplied with the wired version of the headset, and is dubbed a “power module”. The adapter connects to the headset via a locking 4-pin miniature connector (this connector is also directly compatible with all A-T UniPak bodypack transmitters). Besides allowing the headset to be connected to a mic cable, the adapter features a rolloff switch to enable the UniSteep filter at 80 Hz, with 18 dB/octave rolloff, to control noise and stage rumble below the voice fundamentals.
As it ships, the headset has a single, moldable earpiece from which the mic boom and element project, and can be used on either ear with the appropriate gentle bends to the mic boom and rotating of the mic element. The earpiece can be shaped for a tight, secure fit. A two-ear mounting adapter is also included for even greater stability, and the BP894 unit slots into this adapter easily for both left- and right-side use. The thin yet durable 55-inch, 1.4-mm cable is permanently connected to the headset near the junction between the boom and the earpiece, and it appears that this connection is rugged. I like the idea of replaceable cables that attach to the headset with a miniature connector, just because you never know what might happen; however, A-T is a veteran manufacturer of professional audio equipment, and I expect that they have done their best to address most vulnerabilities.
Overall, this appears to be a headset worthy of serious attention, and that will deliver natural voice audio for spoken word and vocal applications in professional settings. The BP894 is available in black or beige, with wired accessories or a variety of connectors for wireless bodypack transmitters. The full wired version retails for $639, and the wireless version for A-T bodybacks is $499.
