AB recording can be a great way to capture stereo sound; and it is also pretty simple, just two omni mics set up a fixed distance apart. This can be done very easily with miniature mics, in particular, as you can see in the Stereo episode.

Here I'm going to show a very lightweight and portable AB rig that I have set up, which can easily be slipped into a backpack, or even a roomy pocket, to carry around as a just-in-case recording setup.

The Kit

If you're looking for a portable recording setup that can do stereo, AB recording is worth a look. This just uses two omni-directional mics, set up a fixed distance apart; typically 50cm or less. With miniature mics with lapel clips, an easy way is to clip them to a stick or branch, or something similar. This can make for a very compact and lightweight rig, which can also make great stereo recordings.

For a self-contained kit, a wooden dowel can be carried to mount the mics on, with a clamp to support it. But there's no reason the dowel has to be in one piece; two separate pieces can be held together by the clamp when in use, and separated for easy carrying. That's the idea behind this kit.

Two pieces of ¼" wooden dowel are cut to a length of around 26-27cm (10½") each. This is the longest dimension of the finished kit. They each have some soft tape (I used gaffer tape) wrapped around one end, to allow them to be gripped in the clamp. This is a common photo/video "super clamp", which has a ¼" threaded hole in the bottom, so it can go on a tripod, or a clamp designed to support a camera. When the miniature mics are clipped to the ends, the centres of the mics are around 47 cm (18½") apart.


The two rods clamped together.

Apart from this, add in a miniature recorder that will work with the mics, appropriate windshields, earbuds for monitoring, and something to support the mics on — like a clamp that can be attached to a handy fence, branch, etc. — and that should make a neat, small kit that you can easily carry around. For a serious recording expedition, I would have at least a proper pair of headphones; but for a "just-in-case" kit, this can work well.


The lightweight kit, with the mics set up on the rod, mounted on a lightweight tripod.

Testing


The kit mounted on a footbridge over a stream.

I took the kit out to Rosemarkie on a cold, calm day to test the rig. One recording was made by a small stream at the back of the beach; the other directly in front of the waves. There's a certain amount of extraneous noise, but hopefully you can get an idea of the stereo image.

The kit is exactly as illustrated above, using Clippy 3.5mm EM172 mics into the Tascam DR-05X. This should work with any decent miniature mics and portable recorder, with just the usual caveat that you want low-noise gear for recording quiet ambiences; many lavalier mics designed for use on actors will be optimised for louder signals. I added a lightweight tripod to support the kit for the waves test.

Rosemarkie Stream AB
A small stream at the back of Rosemarkie beach, recorded using a pair of 3.5mm Clippy mics on the portable AB rig, just in front of the stream.

19 January 2021

Rosemarkie Waves AB
Small waves on Rosemarkie beach, recorded using a pair of 3.5mm Clippy mics on the portable AB rig, just in front of the water.

19 January 2021

More Pictures


One of the mics clamped to the rod.

One of the mics, without windshield.

The test setup for the stream recording, with the kit mounted on a tripod. The clamp and rod holding the Clippy mics is attached to the tripod with another clamp; the recorder is mounted on top.

The test setup for the waves recording, with the kit mounted on a tripod.

The kit set up on a small footbridge over a stream.

View of the front of the rig.