US Launch of Digital Soundfield Microphone System At AES

As broadcasters struggle to meet the challenge of producing 5.1-compatible audio for high-definition transmission, there’s a greater need than ever for a simple means of recording surround sound, one that does away with expensive multi-microphone arrays and complex recording techniques. Fortunately, an easy-to-use digital solution is at hand from UK company SoundField, based on established technology with a pedigree going back more than three decades. The new DSF-2 system, which gets its US launch at AES San Francisco, allows users to output digital audio simultaneously in mono, stereo, and surround sound — and all from a single microphone.

If you’ve never heard of SoundField’s products before, this might seem a complete impossibility. But in fact the technology that makes simultaneous recordings or broadcast possible in all these audio formats has been in existence for decades. All of SoundField’s systems comprise one of their range of processors and one of their patented multi-capsule microphones. The processors produce a four-channel proprietary output format known as ‘B-Format’, which can then be further decoded by SoundField hardware or software into mono, stereo, stereo M/S, or surround sound in formats such as 5.1, 6.1, 7.1 — or any future surround standard. The precise format of audio generated by the microphone can be determined live (and changed if required) by adjusting the output controls on the associated SoundField processing hardware or software. And if the four-channel B-Format audio is recorded to a suitable multitrack storage medium, the decoding can even take place ‘after the event’ in post-production, with the precise nature of the final audio format not being determined until then. The B Format thus has tremendous potential as a ‘future-proof’ archive format, as it will allow post-production decoding of archive recordings to other surround sound formats if these replace 5.1 in the future.

The DSF-2 is the latest generation of SoundField technology, and the first in which all internal processing is performed digitally. The 1U-rack DSF-2 controller unit offers live decoding to stereo, stereo M/S, and four-channel B-Format. The stereo signal may be output directly from the DSF 2 in the analogue or digital domain via rear-panel XLR and unbalanced 75? BNC connectors respectively, while the Stereo M/S and B-Format signals are available only as digital signals. From here, the B-Format signals may be decoded to a variety of surround formats by SoundField’s existing SP451 hardware processor, or by the company’s Surround Zone decoding software plug-in, now available for use with DAWs such as Digidesign Pro Tools, Steinberg Nuendo, and SADiE. Digital output is possible at 48, 96 and 192kHz for the best possible recording or broadcast quality.

If you’re still not convinced that all this is possible, it might be helpful to know that it’s already been done, and under the challenging broadcasting conditions of the 2006 soccer World Cup. The very first DSF-2 systems were used to originate stereo and 5.1 ambience during international TV broadcasts from various German stadiums during the tournament; the stereo output from the DSF-2 was used for SD broadcast, while the B Format output was decoded to 5.1 surround for the HD transmission. The results were so successful that Sky Sports are now using DSF-2 systems for their live HD coverage of UK Premiership matches.

In addition to allowing the user to determine the eventual output format of the recorded audio, the DSF-2 system offers the user very accurate control over the apparent orientation, angle and pickup pattern of the microphone without the need to physically move the mic, and all from the front panel of the DSF-2 controller. Again, although this might sound impossible, it’s all done quite simply by changing the way the multi-channel B-format signal is decoded — and all the user has to do is turn a couple of front-panel controls. Similarly, the apparent stereo width of the output audio is also precisely adjustable. For recording convenience, the DSF-2 processor also offers a user-adjustable gain control, a fixed-threshold recording limiter, on-board four-channel LED metering, a built-in high-pass filter and a headphone jack for monitoring purposes. The processor can drive a mic cable of up to 250m in length, and the processor may in turn be connected to coaxial cables of up to 1km long when the digital outputs are in use. In OB situations where a broadcast truck often cannot be located near the microphone, it’s good to know that the DSF-2 mic can be situated up to 1.25km from the truck without any problems.

The DSF-2 is shipping now, and is being officially launched here in the US at the AES show. For more on the tremendous possibilities the SoundField DSF2 has to offer the worlds of HD broadcast and surround-sound recording, go to, or come to Booth #1313, SoundField’s stand at AES.