AT's new models prove that back-electret designs can offer performance to rival conventional capacitor mics.
The two Audio Technica mic models under review are small-diaphragm 'stick' type microphones, both of which use back-electret technology. This gives them performance comparable to conventional capacitor mics, but also makes them more forgiving of phantom power voltage — the working range is from 11V to 52V, though there's no internal battery power option. Most mixers provide standard 48V phantom powering, but some battery-powered location devices only provide 12V or 24V powering, and in such situations these mics would still work quite happily.
The AT3031 is a cardioid mic with a frequency response of 30Hz to 20kHz. It includes a switchable 12dB/octave low-cut filter operating at 80Hz, and a switchable 10dB pad. Sound pressure levels of up to 148dBSPL (158dBSPL with pad) can be accommodated and the background noise is a respectable 16dB. This adds up to a dynamic range of 132dB with a sensitivity of around 20dB (1V/Pa reference level), which compares well with other capacitor mics.
The AT3032 has a virtually identical technical spec and similar styling, but is an omnidirectional model. Both measure 144 x 21mm and are supplied with soft plastic pouch and stand clip.
These microphones are very versatile, being suitable for high-SPL work, such as percussion miking or drum overheads, as well as being sensitive enough to allow their use with quieter acoustic instruments or vocal ensembles. The frequency response is deliberately flat rather than having any significant presence peak, and the small diaphragm diameter is likely to make the off-axis response less coloured than it would be for a large-diaphragm model.
I tested both mics recording a variety of acoustic instruments and found it extremely easy to get first-class results. Amongst the instruments recorded were viola, accordion, melodica, hand percussion, recorder and acoustic guitar (both steel-strung and classical). Overall, the sound came over as neutral and open with a good degree of depth, both models exhibiting a similar tonal character (or lack of one). The omni sounds slightly more open, as you might expect given its more accurate interpretation of off-axis sounds, and it was surprising how little additional spill you got when using the omni instead of the cardioid. For example, I recorded the viola using the omni around two and a half feet above the instrument, with a hand drum being played in the same room no more than eight feet away (close-miked using the cardioid pattern AT3031). The amount of spill was extraordinarily low — in fact, it was little worse than if I'd used cardioid mics all round.
If you already have a large-diaphragm mic, the models reviewed here would make useful additions to your studio if you are involved in recording acoustic instruments. The sound quality is good, and the mics can cover a huge dynamic range, from ambient sounds to loud percussion. Their ability to run on phantom power as low as 11V is useful if you want a location mic for use with equipment that puts out less than the regular 48V phantom source and, though there are numerous small-diaphragm mics that can produce equally impressive results, these mics are sensibly priced in the UK and well engineered. If you have a short list, put these on it!