Beachtek ( www.beachtek.com ) was kind enough to send over a DXA-SLR active audio adapter for DSLR (and other) camera systems. I hooked it up to a Canon 5D and a Seinheisser wireless to see how good the setup would perform.
The 5D has pretty decent audio recording capabilities - 48kHz 16-bit uncompressed. The problem is that the on-board amplifier is weak, so if you send in low audio levels through the mic input, then you have to compensate by turning up the gain which causes noise in the recording. The auto-gain function is even worse because it will just turn up the knob whenever the room is quiet.
The DXA-SLR sends in an amplified audio signal and is an active pre-amp and not just a passive XLR to 1/8th inch adapter. That means it sends in a strong audio signal to the camera, letting you exploit the full capabilities of the DSLR. Plus the little box has headphone monitoring, an auto-gain defeating circuit (great for 7D and 1D users), an LED readout to let you know when levels are strong (green) and when they are too high (red). There are two XLR inputs and an Aux input, an output for the camera and phantom power for your mics.I set my manual gain pretty low in my 5D, a bit under a 1/4 on the camera's scale. When I tested the audio signal, I was in the green both in my camera and on the DXA-SLR. When I yelled a bit too loud, both the readout on the camera and the led on the box went red. The audio over the headphones was superb and my test footage sounded great. The little box comes with a mounting screw that can easily be engaged with a thumb-wheel. You can mount it on the bottom of your camera or on a rig in a matter of seconds plus it doesn't obstruct the battery compartment on the camera. I tried the box out on my RedRock Micro rig with a Marshall 7" Monitor to see how comfortable it would be for someone filming reality or documentary to shoot like they would with a video camera. My conclusion is that you can count on the DXA-SLR to give you the audio capabilities you are looking for in a professional system. I'll be demonstrating this and other great gear in-depth at my next Canon DSLR boot camp this Saturday, July 17th: www.canonbootcamp.com
photographs by Tom Myrdahl of www.tommyrdahlhdvideo.com