Design
The Azden SMX-30 main selling point must be having both a stereo and mono microphone built in. The stereo microphone is positioned at the top and consists of 2 cardioid polar pattern microphone elements spaced apart at a 120º angle for capturing a stereo image. The mono microphone uses a super-cardioid polar pattern to focus on sound in front of the camera and is equipped with the same high-quality element as Azden’s SGM-250 shotgun microphone. By adding a stereo microphone the SMX-30 becomes a little larger in size compared to other on camera microphones, but it still remains quite compact.
The SMX-30 feature a custom made, shock absorbing shoe mount to isolate the microphone from camera motor and handling noise. The mount is designed to fit the standard camera shoe and comes with a ¼”-20 thread at the bottom for mounting to poles and other camera accessories. The shock absorption works extreme well; even when you shake your camera setup rigorously, the shock absorbers keeps the microphone in position but does not make any noise at all which would be picked up in the audio recording.
The SMX-30 is powered by two AA batteries instead of the 9V battery that is used in some other microphones, this is actually a godsend as we all know how readily available AA batteries are. Azden claims you can achieve 24 hours of operation with a single set of batteries with no degradation of sound quality. The battery indicator LED light will illuminate to let you know when you have one hour of power left, giving you lots of buffer to change batteries. The SMX-30 also has an Auto power setting, it can detect when a camera is on and will automatically power on and off with the camera. This is a very handy feature as you don’t need to keep turning the microphone on or off, and you wont run into the problem of accidentally leaving it on and draining the battery.
The microphone features a +20db gain booster to overcome the low-quality microphone preamps found in most DSLR and small compact cameras, that add noise when the gain is turned up. By using a +20db gain booster you can set the audio on your camera at a very low level to avoid having to use the noisy preamps. There is also a -10dB pad to protect against distortion when recording in loud environments such as live concerts and motorsport events. The SMX 30 also have a low cut filter switch for reducing the level of low frequencies below 120Hz, which is useful for helping remove noise caused by things such as air conditioners, wind and loud traffic.
