Marshal Electronics MXL FR-310 Hot Shoe Microphone Review

The Marshal Electronics MXL FR-310 is another quality external microphone alternative to the weak on-board camera microphones that are common on DSLRs and camcorders.

The FR-310 from Marshal Electronics is a cost effective super-cardioid shotgun-type microphone that mounts directly into the hot shoe of a camera. Weighing 4.8oz (136g) and coming in at 2.5 inches tall and 5.3 inches long, the solid aluminum FR-310 adds minimal weight and size to the camera while infinitely improving the audio of your video recordings.

MXL FR-310 - On camera

The FR-310 is an electret condenser and uses a single 1.5V AAA battery which can last up to 500 hours, which is far and above the longest of any of the current hot shoe microphones. The microphone has controls for three gain levels (corresponding to about -5 dB, 0 dB, and +5 dB) which I found to be adequate enough, but not as far ranging as I’d like.  Furthermore, at all gain levels there was a slightly higher noise floor than I’d have liked to see.

MXL FR-310 - Controls

The MXL features 3 gain levels and both a normal and high-pass filter mode.

From an interface standpoint, the microphone contains a single 1/8″ 3.5mm stereo mini plug to attach to standard cameras with a coiled cable that can stretch out to about 2 feet.  This is very handy if you want to mount the microphone a bit further away from the camera or on some type of larger rigging.  The microphone also includes a high-pass filter mode to help reduce camera operation noise.

As a supercardioid, the FR-310 does a decent job at rejecting off axis sound, which is extremely important for getting clear audio from your subjects.  The included windscreen does a decent job of cutting down wind noise as well. Without an integrated shock mount, though, the FR-310 is fairly sensitive to handling noise and easily picks up camera movements when not placed on a tripod.

MXL FR-310 - On Camera

The MXL FR-310 fits well on any camera.

Overall, the MXL FR-310 is a good microphone and a good competitor to the other hot shoe-mounted microphone competitors. I would have liked to see a better gain range and I found that the audio itself was slightly flat compared to some of its competitors.  The use of a single AAA battery and incredible battery life are huge advantages of it though, and at nearly half the cost of some of its competitors, it makes for a good alternative for the low-budget filmmaker.

MXL FR-310 - Case

The MXL FR-310 includes a handy Aluminum flight case.

You can find the Marshal Electronics FR-310 at various pro retailers for $134.95 and includes a handy aluminum flight case.


  1. says

    Thanks for the review of the FR-310, Kien – great information.
    After watching and listening to the video, I’m thinking of trying the Roide Videomic Pro as an onboard shotgun mic for my Canon 5D Mark II and 7D
    Any recommendations for a lav mic?