After three years of research and development SoundField has released the A-Format SPS200, designed for stereo and surround recording. It is much cheaper than its elder SoundField ST350 and specially designed for outdoor recording: it is rather light (7.75 oz.), Phantom 48V powered, and incorporates four condenser capsules, provided by MBHO GmbH, a german company created by former Schoeps engineers. Thus sound colour of the SPS200 is, of course, close to Schoeps capsule sound colour.
Mounted inside its Rycote windscreen, the SPS200 has a major drawback because of its extreme sensibility to handling noise as to low frequencies. It requires an efficient suspension. So neither can it be used on a boom with this windscreen, nor can it be set into a Cinela ZEPHYX windscreen, because of its length.
Therefore, two solutions were at hand:
- lengthen the Zephyx windscreen, and get a kind of station wagon Zephyx
- shorten the microphone by approximately 3/4"
After a long and vigorous debate inside our technical direction, we chose the second option, validated by the SoundField engineers. Thanks to the dexterity of the Cinela sound surgeon, the mike was shortened by the necessary 3/4 inches, and was fitted to the Zephyx.
Thanks to this elective surgery, the SPS200 can at last be used on a boom, and so, used for feature shoots.
The Ambisonics multichannel technology
relies on a sound localization theory. It is able to reproduce a full sound field by decomposing the complete directional characteristics of this sound field into harmonics components of a sphere, called W (pressure, omnidirectional), X (front/rear), Y (left/right) and Z (up/down), which are the B-Format.
Opposite to others SoundField mikes, the SPS200 outputs A-Format signal, the one directly produced by the four capsules. With this new system, each capsule is therefore directly recorded, allowing to choose preamps and A/D converters.
In order to create stereo or surround signal, after A-Format acquisition, this one must be encoded on a computer thanks to a dedicated plugin provided by the manufacturer (unfortunately protected by iLock dongle). For that, a new version of traditional Surround Zone, the SPS200 Surround Zone software, designed for Pro Tools HD or any VST capable DAW (we can here mention the excellent Reaper from Cockos), directly can encode information at any desired surround format, cardioid 5.1 by default, also bidirectionnal 5.1, hypercardioid 5.1, 6.1, 7.1, 8 or simply stereo, with the different known parameters (rotation, tilt, zoom, rear pattern, front and rear width).
With the SPS200, DC Audiovisuel provides a dedicated netbook Asus eeePC 901, together with a mini external USB soundcard, a gamer surround headphone, with Reaper Daw sofware installed, Surround Zone plugin and iLock dongle, in order to offer the sound mixer the opportunity to listen to his sound recordings. This very light computer, running Windows XP, is specially configured for this purpose and, more, allows to remote control the Cantar recorder thanks to Aaton Tarkan software. On shooting setup, this eeePC has an 8 hours power autonomy with its internal battery and can be charged on the 4th output of the SMO powerstation, if this one has been customized to provide 2.5A on 12V (default is 2A).
A dedicated listening 5.1 room has also been set up in our premises to welcome sound mixers who wish to have an exact idea of spacialization of their surrond sound recording, whether A-Format, whether Schoeps Double-MS.
With this new sound recording concept, will it be necessary to make a clean sweep, “tabula rasa”, of all the things we have learned from our own experience: e.g. MS recording, double-MS, ORTF, and push aside our knowledge to choose this new technology? A huge debate!
DC Audiovisuel wants here to acknoledge and thank Jean-Marc L'Hotel for his valuable contribution to make understanding and work with SoundField in France and his help in introducing inside our company this new technology. For the record, it could be refered to his excellent document (in french) written for the AFSi association "Prise de son multicanal ...itinerente et centree"
(Multichannel recording ...travelling and centered
* This news is so unexpected that one is speechless facing this picture of a saw cutting off SPS200 tube.