LIST PRICE $710 (MB8455B system, with the high-output cardioid mic and 84-inch boom)
Reinforcing a choir performance can be a challenge to say the least. The vocalists are spread horizontally, vertically, and in rows—and within their sections are working to blend their voices rather than stand out. Microphones as a rule need to be unobtrusive, placed at a distance to capture multiple voices, and must provide sufficient reinforcement at that distance to bring the sound to the listeners without the mics feeding back. Various solutions are available, including hanging choir mics, barrier mics, conventional mics on long boom stands, and specialized boom systems.
The Audix MicroBoom series consists of slim carbon-fiber booms in three lengths, with integral mini-XLR connectors at both ends for the cardioid or hypercardioid condenser mic element and the cable to connect with the mixing console, as well as a flexible mic-stand adapter. Just add a conventional mic stand and you have an excellent sounding solution that will give the necessary height and positioning while not obscuring visibility.
For this review, Audix shipped the 84-inch MicroBoom with the high-output M1255B cardioid microphone, and also included the M1255BHC hypercardioid mic element. My first surprise was upon opening the over seven-foot-long, heavy-duty shipping tube, where I discovered a thin, rigid tube that was under a quarter-inch in diameter (0.2 inches/7.4 mm) and weighed just four ounces with the stand adapter removed. “Micro” is an appropriate name for this boom—and the term extends to the microphones in the series, as well.
The polar pattern sounded tonally consistent around the mic to about 65 degrees off-axis…
Mic boom and stand traits
The boom has a TA-3F connector in its upper tip, to which any of the available mic elements will attach, with a push-button to disconnect the mic for storage or to change mics for different applications. Just below the connector is a short gooseneck, measuring 2.5 inches, for positioning the mic. This gooseneck is easy to adjust to any angle up to about 135 degrees from straight, yet holds its position even with bumps and vibration—conditions it would probably encounter in the church setting. At the other end of the boom, a TA-3M connector is used to attach the supplied 25-foot TA-3F to standard XLR-3M low-profile mic cable, which goes to a snake or floor jack to the console.
The boom shaft fits into a stand adapter, which has a thumbscrew adjustment to allow the boom position to be lengthened or shortened along the shaft, and which rotates on a wide arc (greater than 180 degrees) so that the angle of the boom can be set when attached to a microphone stand. When I extended the stand near its maximum height, with the boom angled and the gooseneck positioned to pick up a choir, the mic was at a height of more than 10 feet. The combination of the carbon-fiber boom and the tiny mic was so light that the boom stayed in place at the desired angle without having to crank down excessively on the mic adapter's tightening knob.
Church-able condenser mic patterns
The Audix M1255B mic element sounded quite accurate when picking up spoken word and singing at a distance, through headphones and with speakers. The polar pattern sounded tonally consistent around the mic to about 65 degrees off-axis, so should do well picking up a section of a choir side-to-side and across the rows (Audix includes a brief mic placement guide in the box.). The null at the rear of the mic attenuated quite well across the entire audio spectrum, which will increase gain-before-feedback when properly positioned.
Frequency response sounded full, with crisp, well-defined highs. Per the specifications, frequency response is 50 Hz to 19 kHz. The high-output cardioid element has a sensitivity of -28 dB, which is 12 dB more than the M1250B model at -40 dB—still plenty sensitive, yet when reinforcing at such a distance, the additional gain will mean that the trim controls on the console won't have to be set as high to obtain sufficient level.
Placement and isolation smarts
Testing the isolation and damping of the mic/boom system, I stomped (well, stepped) heavily on the floor around the mic stand, on both wood and carpeted surfaces. I heard some dull thuds reproduced by the system, though they were relatively low in level and quite acceptable. Tapping the mic boom itself, the sound and rattle are reproduced fairly loudly, since the mic element is directly coupled to the end of the boom. (But that's not something you'd tend to do on purpose.) Since these choir mic systems are typically placed where they won't be handled, the mechanical noise shouldn't be a problem. Audix says it has other MicroBoom models that are less susceptible to handling noise, so the bases of most church environments should be covered.
This reviewer's take: the Audix MicroBoom is a well-designed, effective microphone system for capturing choirs and similar sound reinforcement applications. The boom is incredibly lightweight yet stable, the choice of microphone elements allows both broader and more pinpoint audio capture, and it sounds spot on. MicroBoom systems are available in lengths of 24, 50, and 84 inches, with an ample selection of Audix microphone elements. The list price for the MB8455B system, with the high-output cardioid mic and 84-inch boom, is right—at $710.
