Baffled Stereo 2

Continuing the experimentation with baffled stereo, I made an Olson wing while in lockdown. This is another technique covered in my video episode "Stereo". This page describes the design and construction of my Olson wing, and the results of a quick and simple 3-way stereo recording test.

A home-made Olson Wing rig in use.

More information on the Olson Wing:

The Quarantine Wing

The Quarantine Wing from the rear.

(i.e. the what-do-I-have-around-the-house wing). Still stuck in the lockdown, I wanted to continue experimenting with baffled stereo, so I decided to make an Olson wing. This is really easy, specially since I was just experimenting — I wasn't remotely fussy about dimensions, I just threw it together from material in hand.

The build is really simple. I cut a yoga block in half, and spray-glued it down onto a base plate made of two sheets of foam core stuck together. Two miniature (lav) mics then get stuck down on to the wings. A thread adaptor was epoxied into a rough hole in the bottom, to make a tripod mount.

The dimensions are basically random, but the block ended up being 145mm wide, 205mm back-to-front, and 50mm high; the wings project 45mm on either side. There's no theory behind these numbers, this is literally what my scrap materials came to.

I just fastened the mics to the wings with gaffer tape, since this is really easy, and allows me to play around with placement. I started with the mics 50mm back from the leading edge, which seems to work. This dimension is pretty critical, though; you can see that I marked a scale on the wings to let me experiment with different placements.

The Quarantine Wing from the rear on its mounting clamp.

The bottom of the Quarantine Wing.

One of the mics mounted on the left wing.

Testing

The test setup: a Jecklin Disk above an ORTF rig on the left, and the Olson wing in a fleece wind cover on the right.

Testing opportunities were still very limited due to the lockdown, so it was back to sticking mics out the back window of my flat. As this was getting towards the end of May the dawn chorus was well past its peak, but there was still enough activity to be interesting; so I left the mics out overnight to see what would happen.

For the sake of comparison, I tested three stereo rigs together: an ORTF blimp containing two MKH 8040s; the home-made Jecklin Disk, with two Comica CVM-V02O miniature mics; and the Quarantine Wing, with two Clippy XLR EM172s.

The test setup from the side.

The idea of the test is to show the different kinds of stereo effect these rigs produce, but please bear in mind that this setup has severe issues:

• The ORTF recording is very noisy. This sounds like external noise to me, rather than mic noise, so this may have been due to placement; the ORTF blimp was hard back against the wall and underneath the windowsill.
• The Comica mics on the Jecklin disk are really cheap and quite hissy. Yes, I'd love another pair of Clippys!
• The Olson wing is really rather random. In particular, the distance the mics are set back from the front is critical. The distance I used here was pretty much a guess, so experimentation might produce much better results.

Here are 2-minute excerpts from the recording. These excerpts were recorded exactly in parallel, so you can compare like for like.

A Longer Sample