The U is for USB, Making This Little Brick One of the Most Versatile Pieces of Audio Gear You Can Buy

One of the unsung heroes of a video shoot is the audio mixer. Chances are, unless there are only two mics being used (the normal number of audio inputs on a pro camera), you have an audio mixer to combine the multiple sources into a stereo mix for the record. On larger shows, you may be taking a feed off of the classically shaped sound boards sporting more than 32 channels in some cases. Out in the field, you need something more portable, with fewer channels. These audio mixers are more brick-like in form, and can run from two to eight channels. One of the reasons they can be more compact is that, unlike the boards, they have no sliders for audio levels or controls for EQ, just basic dials for controlling levels and panning.

I've always had a soft spot in my heart for audio mixers; I own almost as many audio mixers as I do HD and 4K cameras. I have all types, including Azden's prosumer Cam-3 (a three-channel mixer the size of a deck of cards), the Mackie 1402 16-channel live show board, the 16-channel Behringer 1600-watt powered live show board, an Azden FMX-32, and lots in between. All have different jobs and applications. The ones I like best are the ones that boast more capability, and the FMX-42u does that by working not only as a field mixer but also as an audio interface with a computer, something I use fairly often for recording voiceovers and digitizing archival audio media.

Physically, the FMX-42u is a solid piece of equipment. If you had it in its included case and were accosted on location, you could easily swing it around as a weapon that would crack skulls. It has a very intuitive layout. On the left side, you have four XLR inputs, each with its own mic/line/pad switch and phantom power switch. This allows you to use a wide range of audio sources and mics. On the right side, you have two XLR outputs, a 1/8-inch mini-jack output, a 1/4-inch headphone jack, USB out, and external power input. The front has five rotary dials. The four to the left with the white caps, are the input level, with an outer ring controlling the pan between the left and right outputs. The fifth rotary dial, with the gray cap, is the master level mix control for output to the recording device. On top is the battery door, where you can insert 6 AA batteries for mobile power. Included with the mixer is a functional bag that gives it some protection during transport and has a strap allowing it to be worn around the neck by a location audio person. It has velcro openings to allow you to plug in audio cables and a clear plastic window that gives you some protection when working in inclement weather.

On my first job with the FMX-42u, I used it as an audio interface for a computer. One of my clients wanted me to digitize some 45-year-old audio cassettes from his bar mitzvah. The hook-up was simple. The FMX-42u connected to the HP workstation with a single mini-USB cable (not included) on one end. On the other, I connected the cassette player via RCA-to-XLR cables. On the PC, I ran Adobe Audition, my application of choice for audio capture and editing. You may need to go into Audition's audio hardware preferences to instruct the program to use the “USB audio interface.” You also need to set the capture settings — that's 16-bit 44.1 KHz for CD audio or 16-bit 48 KHz for video production. Even though the mixer has four inputs, the USB only puts out two channels. For capturing a stereo cassette, that is no problem. For the best results, pan the left channel all the way left and the right channel all the way to the right. Once everything was hooked up and calibrated, the capture went smoothly. Riding the dials while listening to the output on headphones and watching the analog sweep-needle VU meters was easy, and the recorded quality was great. As the FMX-42u runs on 6 AA batteries, I'd advise anyone who wants to use it as a computer interface to get the optional AC adapter.

Azden FMX-42u


In this location set-up, the XLR audio outputs are feeding the interview camera, and the USB interface is connected to a computer that is recording and monitoring audio.

For my next test, I used the FMX-42u as a field mixer. The shoot was for a private family-history documentary. The person on camera was the 89 year old patriarch of a Jewish family who remembered Kristallnacht, the infamous "night of broken glass” when Hitler held his first official violent anti-Jewish riot, instructing the SS and others in the Nazi party to destroy Jewish businesses, homes and synagogues. (Emergency services weren't allowed to extinguish flames.) The man, who was 12 at the time, got out with his family and moved to Chicago. Although he was too young to serve in the Second World War, he did serve in the United States Air Force afterward, as part of a wing occupying Germany. It was interesting listening him talk about leaving as a persecuted kid, then coming back to his old town in an American Air Force uniform and seeing the reactions of his former Nazi neighbors.

For this shoot, aside from the FMX-42u, I used my Sony HVR-Z7u camera with a Sennheiser G2 wireless lavalier on the subject. I used an Azden SGM250 (to be reviewed shortly) on a mic stand as back-up and to record the man's son, who was also the interviewer. I had the FMX-42u on a table next to me as I was shooting. The controls are well laid out and easy to use. I love the large VU meters, which are very easy to read. In dark situations, you can turn on a backlight. And the audio quality was excellent. Some more cheaply made audio components can introduce unwanted noise, but this audio was as clean as could be.

So the FMX-42u works as well on location shoots as it does when used as a computer interface for digitizing analog audio media or recording voice overs. It is an extremely flexible piece of equipment. If you were like me, you may have thought of Azden's inexpensive WMS-Pro mics and Cam-3 mixer when you hear “Azden.” But the quality of the FMX-42u is on a much, much higher level. If you need a very good four-channel field mixer that can do double-duty in the edit bay as a PC audio interface, the FMX-42u is the only one I've seen that does both, and does them well.I highly recommend the FMX-42u for all of your field audio mixing needs—and many of your in-studio needs as well.