By Frank Lockwood
The recordings described here were done at the Church of St. Mary Magdalene in Toronto from January to May, 2009. This article is based on a presentation given by Frank Lockwood to the AES Toronto chapter in January 2014.
Editing & Processing The Mix
The next stage was to assemble the whole piece, with the correct timing,
from the various takes. The Pyramix DAW is the choice of most classical music recording specialists worldwide because of its superior editing controls. The crossfades and the sound material can all be shifted in time independently in order to perfectly align the “Out” and “In.” The crossfades can be made longer or shorter, and the fade shapes can be modified as spline curves. The goal is to create a seamless transition from one take to the next so that the listener is not distracted by any sudden shifts or changes in the sound quality that are not part of the music.
I completed the editing from all the selected takes and then identified which sections belonged to either of the two choirs. The Choir II sections, with all the fades, were moved (constrained in time) to four new tracks so that each choir could have its own processing chain.
The intention was to create an antiphonal performance, where one choir sounds close and fairly narrow, as though positioned in front of the listener, while the other sounds distant and spread apart, as though standing in the aisles near the back of the church.
Processing the “near” choir was relatively simple, since they had already been recorded with the suitable perspective. A very light amount of compression was used to tame some of the louder peaks, and then the stereo panning was narrowed, creating a more compact grouping to contrast with the wider, distant choir.
Creating the impression of a distant choir required more elaborate processing: equalization to change the tone quality; dynamic range compression to reduce the soft to loud range; and stereo adjustment to increase the width. I had to consider the characteristics of distant sound and then synthesize them as naturally as possible.
High frequency sounds traveling over distance are absorbed by the air more readily than low frequency sound, so I used an equalizer to roll off the highs. At the same time, some of the lows were reduced as well, to diminish the power and presence experienced when a choir is standing close to a listener. With increased distance, the difference between soft and loud sounds becomes much less pronounced, so a compressor was used to reduce and control the dynamic range of the main microphone
pair’s signal, allowing the room mic signal to predominate.
Next, I used a stereo width control – essentially an M/S matrix – to reduce the middle component and increase the side, spreading the distant choir sound apart to contrast with the narrowed grouping of the closer choir at the “front.”
Finally, impulse response reverberation was applied to both choirs with a plug-in processor, using one of the impulses created from the impulse response collection session described in part one of this article. This restored any reverb tails impacted by the de-noising process, while bringing everything together into a single room. In this graphical representation of the postproduction, starting on the left it begins with the noise-reduced and edited takes, which are split into the two choirs. The close choir has only gentle compression applied and is panned inward towards the centre. The distant choir is equalized, rolling off the top and bottom, compressed more radically, and its width is adjusted. Both choirs are sent to the IR reverberator with the SMM impulse response. The outputs of both choirs plus the reverb plug-in are sent to the master stereo summing bus where the peaks are limited and the low end rumble is removed. Everything is mixed down to a single stereo file for placement in the CD running order.
“The Reproaches” was just one of several pieces of music featured on the CD, so another Pyramix session was created to place all the stereo mixes in the proper order and timing, along with CD start and stop ID markers. Copies of this recording can be obtained directly from the choir of the Church of St. Mary Magdalene, or through CD Baby, Amazon.ca, and iTunes.
Parts 1 & 2 of this article appeared in the April & June 2014 issues of Professional Sound, respectively. An expanded version of this article, with audio examples and more pictures, can be found online at www.LockwoodARS.com/production. Frank Lockwood is the owner/operator of Lockwood ARS. Based in Toronto, he specializes in classical and acoustic music recording, editing, mixing, restoration, and