ORTF is lovely way to capture a nice stereo ambiance; but it can be challenging to set up and carry around, as it needs two cardioid mics, the right distance apart, and with the right angle between them. And then there's windshielding to worry about. But it's still a great technique, and you can learn more about it in the Stereo episode.

Now FEL Communications (a.k.a. micbooster.com)micbooster.com
FEL Communications, a.k.a. micbooster.com, makers of miniature mics. (FEL Communications)
https://micbooster.com/ have started supplying cardioid EM264 capsules in their popular Clippy form factor. This opens up the possibility of building a small, compact ORTF rig, which is relatively easy on the pocket. So, I decided to give it a try, and here's how it went.

Supplies

The idea was to build a low-cost ORTF system, and see how good it could be. The core of the kit is the Clippy XLR EM264Y mic from micbooster, in a stereo pair. This is a very compact and handy mic for a cardioid. (They do have unbalanced, 3.5mm connected versions in the works.)

The EM264 mic takes the same windshield as the regular EM272 mics; so I also bought a pair of foam windshields, and a pair of the Rycote windjammers. (The windjammers go on over the foam windshields.)

Other than that, the rig was built using scrap material to hand; basically a scrap of foam board, and another of sticky-backed foam board. Rather than try to incorporate special mic holders, the mics will be clipped to this board using their own supplied clips.

So, the total cost was:

Component Count Cost
Clippy XLR EM264Y, Stereo 1 £141.48
Rycote Clippy Foam Windshield 2 £7.32
Rycote Windjammer for Clippy Mic 2 £33.36
Total £182.16

Interference

FEL warn very clearly that the EM264 capsules are prone to electrical interference. My experience is that indoors, mains hum is certainly an issue. Outdoors, I didn't notice any problems; but you can hear for yourself below.

The Build


The mic layout, sketched out on a scrap of foam board.

The main part of the rig is a simple piece of foam board, cut to shape and size so that two mics clipped to the edges of the board are held the correct distance and angle apart.

A small piece of scrap was used to test how far offset the mics would be from the edge of the board when clipped to it, and the results were used to lay out the main board.



The two pieces of foam board glued together. The ends have been trimmed to clear the mics.

A second piece of foam board is cut to the same shape, but with slots cut in the sides to guide the mic clips to the correct places. This is then stuck underneath the main piece.



The finished rig, with the mics clipped in place, from underneath.

And that's it! The mics simply clip in place with the clips guided to the correct place by the slots, so you can get them in the right place every time. Building it didn't take more than an hour or so, and that was with the TV on.


It would be easy to glue a ¼" insert into a hole in the plate, to allow the rig to be mounted directly to a tripod. However, I elected to simply hold it in a clamp, which I already have.


The finished rig.

Testing


The test setup, as used to record the steam train.

The mic rig clamped in place.

I tested the rig out in direct comparison to a pair of Sennheiser MKH8040 mics, just to see how it would hold up. The setup was as shown above: the Sennheisers were in an ORTF shockmount inside a blimp with a deadcat; and the Mini-ORTF rig was mounted below, with the two Clippy XLR EM264 mics. Both stereo pairs were recording simultaneously into the Zoom F6, so you can compare exactly equivalent recordings. The whole rig was mounted on a lightweight tripod.

I tried the rig out in a couple of locations: beside a small stream, and recording a steam train passing. It was a bit windy for the stream; you can hear that the Clippys are somewhat affected by this. The Rycote windjammers are good, but they can't compete with a proper blimp and deadcat (also Rycote, BTW).

Glenmore Stream: Sennheiser MKH8040
Sounds of a stream in Glenmore forest park, recorded with two Sennheiser MKH8040 mics, in an ORTF arrangement, inside a blimp with a fur deadcat.

3 September 2022

Glenmore Stream: Clippy EM264
Sounds of a stream in Glenmore forest park, recorded with two Micbooster Clippy EM264 mics, in an ORTF arrangement, each with Rycote windjammers over foam windshields.

3 September 2022

Strathspey Steam: Sennheiser MKH8040
Sound of a steam train on the railway at Strathspey, recorded with two Sennheiser MKH8040 mics, in an ORTF arrangement, inside a blimp with a fur deadcat.

24 September 2022

Strathspey Steam: Clippy EM264
Sound of a steam train on the railway at Strathspey, recorded with two Micbooster Clippy EM264 mics, in an ORTF arrangement, each with Rycote windjammers over foam windshields.

24 September 2022

More Pictures


The layout marked up on the foam board scrap.

The foam board base cut out.

The bottom plate, with the mic guide slots cut out.

The two pieces glued together, with the ends trimmed to give the mics clear space around them.

The mics in place on the finished rig, from above.

Closeup of one of the mics mounted.

Another view of one of the mics.

The mics mounted, with windshields, from underneath.

Checking the spacing of the mics.

Checking the angle of the mics.