You are here

The Double Mid-Sides Array

On The Double
Published June 2017
By Hugh Robjohns

A modified Double M-S array being used to record a  singing guitarist.A modified Double M-S array being used to record a singing guitarist.

M-S miking is already a versatile technique, but it can be built upon to provide surround-sound recording and a whole lot more besides!

The Mid-Sides (M-S) stereo mic array should be familiar to most recording enthusiasts, but an interesting variation on it, often used in film and TV, is less often seen in music production. Called the ‘Double M-S’ or ‘MSM’ array, it offers several unique advantages and, usefully, the position of its two central mics can be altered to create a very versatile multi-directional (not necessarily ‘surround’) array with excellent mono compatibility. This makes it a good contender in situations such as recording a singing guitarist, where you might want some separation between two sources but wish to retain some sense of stereo width, or sources such as choirs, where it might be desirable to capture both the front and the rear in stereo. To understand how this array works you must understand the principles of coincident arrays in general, and of Mid-Sides in particular.

Coincident Arrays

In all coincident mic arrays, sounds from any direction always reach all the capsules at the same time, because the capsules are mounted very close to one other, so their signals are always phase-aligned. In a typical stereo coincident array, the capsules are arranged one above the other, such that they’re perfectly aligned in the horizontal plane, and the sound sources should be arranged to lie on the same plane. This deliberate avoidance of inter-channel time differences is critical to the precision of the perceived stereo image when the stereo signal is auditioned over stereo speakers; the physical spacing of the speakers creates the inter-aural time differences that our ears require to locate sound sources. The absence of time differences also removes the possibility of audible coloration due to comb-filtering, and guarantees mono-compatible recordings.

In typical stereo ‘X-Y’ arrays, the two capsules...

You've only read 10% of this article, so to continue reading...

Option 1: Login to read this article if you have a Digital Subscription or Industry Controlled Circulation account

  • To read the full article online (in HTML browser format), please LOG IN at the top of this page.
  • Note: Your Digital subscription does not include downloadable PDF articles free of charge.

Option 2: Buy a Digital sub from our shop

  • A Digital sub can be bought from our Shop and used immediately, or contact our Subs staff to discuss an upgrade price to add Digital access to your existing Print subscription.

Option 3: Buy and download this SOS article in Adobe PDF format

  • Buy this article now and immediately download the PDF file to your computer.
  • PDF articles look identical to the printed magazine layouts (but exclude advertisements).
  • Note: Some shorter articles don't always have a PDF version.
Published June 2017