Choir, Classical

Recorded live at the Oscar Peterson Concert Hall

Dec 2009

Sound Recording: Navid Navab and AJ Bouchard , Mixing and Mastering: Navid Navab

Text: Accesses the paper here and download it as your prefered format.


We took our time to setup the main stereo pair as perfect as possible. For main stereo pair the Brauners were aranged as an ORTF pair, placed off the stage, angled roughly 15 degrees downwards and raised just high enough so that the pair was looking into the heart of the massive choir, catching a bit of piano's opening as well as the singer's mouths. Since we were dealing with a massive choir and a series of unexpected changes, the ORTF angle was chosen to provide the appropriate width for capturing everyone in the choir.

Also, a spaced pair (km 183s) was placed about 6 ft away from the main stereo pair, they were also raised almost to the same hight brauners. Thanks to the full low end responsie of the 183 and their omni directional pattern, the spaced pair capture a certain warmth and ambience that the brauners cannot.

A delay (time-adjustment) of 570 sample at 96000 sampling rate was added to the brauners' insert in protools to compensate for the distance between the two stereo pairs. Ofcourse I arrived at 570 samples by converting the distance between the spaced mics to milliseconds and then milliseconds to numbers of samples at our specific sampling rate.

The Brauners were mixed in at 0db and then the 183s at -4dB. The overall mix sounds very spacious and wet. This is an easthetic choice that I found appropriate for this recording. All through the recording one can hear the hall and other "live" aspects of the performance, including occasional audience noises. However, should a client as an example complain about the wetness of the recording I can always bring the 183s down by as many dBs as needed to achieve a different sound.

Post Processing:
Although adding extra dynamic processes to classical recordings and specifically to voice is almost forbidden, I decided to experiment lightly with some mastering tools. On the master track, the Izotop ozone 3 plugin was added. After a lot of listening tests the following functions were activated and used subtly:

Multiband Stereo Imaging (only 0.1 dB on the highs)

dynamic EQ (0.6dB the low end)

This could be an overkill but It seemed to my ears that the above proccesses gave more life to the recording's space without being destructive.

Issues and impression:
1. Our 2 pairs of stereo mics were not throughly effective for properly capturing the few pieces that were strictly for a solo voice and piano. This is evident on track 4 and 6. The 183 on stage-left is picking the solo voice and acts as very rough spot mic while the Brauners pick up the piano. The main problem to my ears is that the stereo imaging is too heavy on the left. I once dealt with this problem by leaving the 183 on the right out of the mix and instead only mixing the stage-left 183 with a center pan. This solution improved the overall imaging and sound to a certain degree. However, unfortunately the tracks provided here are from a different mix and the carefully corrected mixes for track 4, 6, and 10 have been lost (in my stolen laptop). Note that I had only about 45 minuets to go in the studio and perform a new generalized mix of this concert during someone else's booking.

2. For the second half of the concert specially I would now like to place the mics a bit further because I think the ortf on the smaller chamber choir yeilds almost too much spatial clarity than needed. This is however a matter of taste and is not a real big issue. In fact many people might prefer this width. To deal with this issue, I added a bit more reverb to the second half of the concert to wash over the voices a bit. Also I didn't use any stereo imaging proccesses on the second half. While the first half (a big choir) benifited from subtle multiband stereo imaging, the second half almost needed the opposite effect. The second half of the concert is not available for download here. However, they are available upon request.


Oscar Peterson Concert Hall

Dec 2009
Text: Accesses the paper here and download it as your prefered format.


Ambisonic panning, ambisonic mixing, spot mics, spatial reconstruction, virtual microphones, spatial sound synthesis