Audio-Technica ATM31a

I've been playing music for 40 years and recording for about 10. I'm strictly a hobbiest, though one who's learned a lot by self-study and experimentation.

I play in a couple of bands and record occassional demos of my own bands and my daughter's school concert band. I also do occasional recording work for friends - mostly solo and small ensemble work.

I record with a Digidesign 002R over firewire into a laptop computer. I record using either ProTools LE or Sonar and mix using Sonar.

The ATM31a is a cardiod small diaphragm condenser. I sometimes use one mic as my vocal mic on stage. More often, I use a stereo pair in an XY configuration as overhead mics for drums or for recording ensembles at a distance.

I love the way the mic sounds on my voice, which is thin and high for a male voice. The mic has crisp highs to give my voice presence but also has a significant proximity effect which gives me the bass boost that my thin voice needs. But the mic is too sensitive for small indoor stages resulting in feedback problems. Thus, I only get to use it when playing outdoors or on large stages where I can put some distance between the mic and the monitors.

When recording demos of my band, I position the XY pair of mics on a stand slightly behind the drummer about 6 feet high facing the center of the kit. Since I usually record the entire band live to 8 tracks, I have to submix the ATM31as with the kick drum mic onto a single channel. Thus, I lose the stereo image, but still enjoy a full sweep across the kit by combining the polar patterns of two mics. I individually mic the toms with dynamic mics and submix them to another channel.

At mix time, I normally duplicate the overhead/kick track and separate out the kick by rolling off the high frequencies. To create the final drum mix, I start with the unprocessed overhead/kick track and then add the processed kick track and the tom track as needed to balance the sound.

The overhead/kick track is a surprisingly accurate reproduction of the entire drum kit. The ATMs capture the cymbals and snare with great accuracy and also do a decent job at picking up the toms, especially the attack. Adding in some portion of the tom submix usually rounds out the drum mix by providing more bottom end and sustain from the toms.

In a pinch, I can make do with only the overhead/kick track by boosting the low mids to emphasize the toms and rolling off a bit of the highs to compensate for the placemnt of the ATM31a pair (closer to the cymbals than the toms). I wouldn't record for a CD this way, but it's very usuable for demos and live recordings.

As a testament to the mics sensitivity, I sometimes amuse myself by listening to the between song and between set audience chatter that the mics pick up at live performances. I can often clearly hear conversations that are 30+ feet away from the mics. Perhaps I should consider blackmail as a sideline :-)

For recording my daughter's concert band (50+ instruments), I use the ATM31a pair in XY configuration on a stand as high as I can get it off the ground (6-7 feet with my stands) and 10-15 feet behind the conductor. As with the drum overhead micing, the XY configuration combines both polar patterns to produce a wide enough sound field to cover the entire ensemble (about a 160 degree spread).

I record each mic to separate track and produce a stereo final mix. Since the recordings are only for the conductor to critique the performance, I do minimal processing to generate the final mix, typically some minor EQ tweaking to balance the bass instruments with the rest of the band, depending on the room acoustices. I did once have to use three or four notch filters to remove the primary and harmonic frequencies of a furance blower that the mics recorded with "stunning" accuracy!

The recording quality in this setup is very good. I can clearly hear and locate each instrument in the mix, and the conductor can zero in on the "bad" notes and other performance gaffes. I sometimes wonder if some of the underperforming band members wished that the recordings weren't quite so accurate :-)

In terms of bang for the buck, these ATM31a probably can't be beat. The only complaint I have is that they can be too crisp - a bit of overemphasis in the 10,000+ Hz range. But that's an advantage in some situations such as drum overheads and recording a concert band in a boomy room. And for the money, I can't imagine a cardiod cond