Tag Archives: surround microphone techniques

Surround recording techniques: Double M/S and IRT Cross

17 Jan

As part of the tasks to complete for our Digital Studio Production module at the Master in Audio Production in Salford University, we were asked to do two surround location recordings with portable equipment if possible. These recordings would be later mixed into 5.1 Surround format in the studios as part of our assessment… and it’s also good fun too!

The first recording I did in this fashion was not properly “on location” but in our University’s recording studios instead, using their equipment in full. It all happened before the Christmas break, when some of us Master fellows joined there to make a “jam session” (some noise with instruments ¬†such as guitars, bongos, a battered drumset) and record the resulting soundscape. The goal was to set ourselves as far in the corners of the live room as possible so as to create a wide soundscape to recreate via surround recording techniques.

My setup of choice for this surround recording was the Double M/S technique. But not the usual one with two Mid microphones and one Side microphone for both of them, all sharing the same space in place. Instead of that, I decided to use Curt Wittig’s techniquue, shown in ‘Spatial Audio’ book by Francis Rumsey. In this one, two separated MS pairs of mics are used: one of them will give the front signal and the other one will record the rear signal. ¬†According to Mr. Wittig, the rear MS pair should be placed back in the room at a distance from the front pair further than the room’s Critical Distance (DC).

Double MS Diagram

Double MS setup diagram (taken from “Spatial Audio” by Francis Rumsey)

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