The Audio Technica BP 4029 Shotgun Mic
Capturing field audio in stereo is one way to meet the demand for a richer, more realistic soundscape, particularly with the rise of 5.1 surround sound. Unfortunately, prices for professional stereo mics, especially shotguns, haven't dropped quite as dramatically as for many other tools of trade. Hence, it's still as tough today to find a decent pro stereo shotgun mic for much less than $1,000, with few exceptions. One of these is from Audio Technica. They do offer a stereo shotgun mic selling for less than that 1K figure. Prototypes leading to the current line were used in the 2000 Olympics in Sydney and had to be sensitive enough to pick up natural sound from a fairly long distance. Today, the descendents of these shotgun mics have become the A-T BP 4029, a "standard length" model, and its longer BP 4027 brother.
The most popular member of this pair is the BP4029, which was the model selected for this review. At 9.3-inches long and nearly an inch in diameter, it's de-signed for everyday on-camera recording. As it weighs only 3.6 ounces, it's ideal for use with the full spectrum of pro cameras and camcorders, and with standalone audio recorders. Its size also means that it can use many of the windscreens and windsocks marketed for "standard" shotgun microphones.
The BP 4029 includes two different microphone components for both a cardioid and a figure-eight pickup pattern. Together, they provide a wide frequency re-sponse from 40 to 20,000 Hz. The mic also has a switchable low frequency roll-off for rumble and other noises below 80 Hz.
The A-T models offer a choice of three operational modes, including a midside or "M-S" capturing mode. (M-S refers to the capture of separate signals from the middle and side of the microphone.) In the BP 4029, the central element has the cardioid response pattern and in normal use faces the middle of the sound stage. The audio from this element is fed to one mixer channel, with the output to the other mixer channel fed from the element with the figure-eight pickup pattern, which picks up audio from both sides of the capsule. Each channel can be independently adjusted with the mixer or in post-production.
The other two operational modes combine these signals internally, providing traditional left/right stereo outputs without external mixing. One of these features a moderately broad pickup pattern with significant ambience, while the other has a narrower pickup pattern that does a better job of isolating point source sounds. According to Audio-Technica, this three-way modality is unique among shotgun stereo microphones in this price range.
These mics also have a very respectable dynamic range. For the BP 4029 this is 101-102 dB for mid, side and L/R stereo, and a 127 dB maximum figure for the side input. The mic's S/N is specified as 72 dB (mid), 68 dB (side) and 70 dB (L/R stereo).
The output connector is a standard 5-pin XLR. As with most stereo mics, the requisite shielded two-conductor cable has a 5-pin female plug on one end and a pair of 3-pin male XLRs on the other for plugging into appropriate inputs on the camera. The mic's 11-52 V phantom power is also fed through this cable.
The BP 4029 comes with a stand clamp for standard 5/8-inch threaded mic stands, a 5/8-27 to 3/8-16 adapter, as well as a foam windscreen and a foam-lined hard plastic carrying case.
I tested the standard BP 4029 shotgun kit with multiple cameras, but mainly with the Canon XL H1. During my evaluation I chiefly shot wildlife and other outdoor subjects and scenes. The first accessory I added was a Koala windsock, a "softie" that slipped snugly over the AT 8134 foam windscreen. The mic barrel fit easily into Canon XL H1's shock mount mic clamp. In fact, I was able to add a little dense foam for extra dampening. The camera mount easily sup-ported the lightweight BP 4029. Initially, my applications for the shotgun microphone were twofold: for interviews and for natural sound, with the latter linked to the behavior of certain wildlife—birds singing, squirrels chomping acorns, deer rattling antlers and horses galloping. These animals and their ac-companying sounds were recorded at anywhere between 20 and 300 meters or more distant.
As expected, I found that for the best results with longer shots it was critical that the mic be precisely pointed at the sound source. This was whether it was in the narrow or wide matrixed modes, just as with a mono shotgun microphone.
To minimize camera handling noise pickup, I mainly used the mic's narrow matrixed mode, which provides a polar pattern with a 90 degree arc. This was also the best mode for interviews where background noise levels needed to be kept to a minimum. With the narrow setting, the sound levels drop off sharply outside the frontal 90 degree pickup pattern.
I also conducted some interviews using the wide matrixed mode, particularly in applications where I needed some intermixed ambience. One example in-volved a series of interviews done on the fly at a protest rally in mid-town Manhattan. I wanted to capture the energy of the event and needed to include some protest chants, lively conversations, cars honking in support and other sounds that might be associated with such an event. Of course, these sounds could not be allowed to overpower the words of the speakers during the interviews.
When using the wide matrixed mode, I always kept the mic within several feet of the interviewees and pointed straight at their mouths. I was also very vigi-lant about the level of ambient noise/sound behind them, changing my camera angle whenever such sounds became problematic. By doing this, I was able to capture good interviews most of the time, with only a few noticeable spikes in background noise levels.
As an added precaution I made full use of the low-frequency roll-off switch for dampening the rumble of traffic and camera handling noise. In general, the ambience level turned out surprisingly good, and it added a "cinema verite" flavor to the interviews without distracting from the speakers. I also used the mic's wide matrixed mode for recording purely ambient audio to be combined later in post production. For this application I recorded with both the camcor-der and a separate digital audio recorder.
For recording distant sounds, particularly those synched to subjects appearing on camera, I found that the narrow matrixed mode was ideal, especially for pinpoint recording of anything more than 60 or 70 meters away. It was also very useful for shooting interviews in noisy environments. I was quite satisfied with the audio quality of interview recordings with the narrow setting, as this kept background noise to a minimum. However, as the distance to the subject increased, a correspondingly greater amount of ambience was picked up, but unlike a mono mic, the recorded ambience possessed more texture. This made for some surprisingly rich recordings of distant wildlife sounds, including the clatter of horses' hooves more than 200 meters away.
I was often surprised at how well the mic captured such sounds, even if they had seemed faint to me when recording. Initially I thought I'd need a longer stereo shotgun, such as the BP 4029's cousin, the BP 4027, for such long reaches. However, I was pleasantly surprised by the BP 4029's sensitivity when cap-turing realistic natural sounds at distances, especially when the wind was calm.
As I typically don't work with a separate sound person and mixer, I avoided the non-matrixed M-S mode, except for some basic testing. In this trial, I compared signal strength with that of the other two modes. Interestingly, it was consistently stronger and louder than what resulted in the two matrixed modes.
My only complaint with the mic is basically one of ergonomics—the difficulty in switching between modes via the recessed microswitches. These are small and require the use of a sturdy and pointed instrument. I found that ballpoint pens, knife points and most screwdriver tips just weren't up to the job. How-ever, the tip of a very small screwdriver could activate the switches. Short of switch redesign, A-T needs to provide a tool for performing this critical task; something that could slip on a keychain for convenience. However, it seems that with just a little bit of rework, a ballpoint pen could be made to work.
I used the BP 4029 in hot, rocky, windy and dusty desert terrain, going up and down rock slopes and through dense thickets, so I can attest that it's rugged. I did lose a softie and windscreen in one particularly dense thicket, but the BP 4029 delivered the same good audio available before this encounter.
The BP 4029 is a versatile stereo shotgun mic with a choice of three recording modes, two internally matrixed and a standard M-S mode, allowing inde-pendent adjustment of output from the mid and side elements independently via a mixer, or later in post. All three yield very realistic stereo recordings when used correctly.
The BP 4029 is amazingly lightweight for its size, and yet is rugged enough to withstand plenty of jostling, abrasion and temperature extremes ranging from 120 degrees to sub-freezing temperatures and even frigid rain. It delivers the quality needed for EFP and comes with a price point and ruggedness that fits ENG applications.
Carl Mrozek operates Eagle Eye Media, based in Buffalo, N.Y., which specializes in wildlife and outdoor subjects. His work regularly appears on the Discovery Channel, The Weather Channel, CBS and other networks. Contact him at [email protected].