New 5.1 Surround Mics Open Creative Audio Possibilities for HDTV on Camcorders
Since the beginning of television, audio has always followed video in technological development. Yet, even when testing the first DVD home video systems, researchers always found that it was the rich surround sound that most impressed viewers.
Now that HD camcorders are the norm and most new production uses 5.1 multi-channel sound for audio, portable surround production is catching up. A leader in this market has been Holophone, a small audio specialty company founded in 1994 by Michael Godfrey, then of Rising Son Productions, a audio post production company located in Toronto, Canada.
While working on numerous albums and providing sound design services for film and television projects, Godfrey was driven by a memory of listening to a Pink Floyd Album over headphones in the 1990s while walking on a beach in IOS, Greece.
Soon after, he began experiments with a binaural microphone system in a dummy head to emulate how the human head receives and experiences audio signals. From this, Godfrey developed the Holophone surround system, which included ten microphones arranged in an enclosure roughly the size and shape of a Nerf football.
Such an arrangement would capture all sound complete with detailed ambiance, providing greater localization and a more realistic listening experience of the recording.
Rising Sun Productions was granted a patent for this unique utilization of microphones and for the Holophone surround sound microphone system. The Canadian National Research Council joined a collaborative effort to further refine the Holophone system, ensuring compliance for all professional audio recording applications.
Today, the Holophone surround system is available in a variety of models, from the high-end H2-Pro, priced at just under $5,000, to the low-end PortaMic 5.1 professional surround microphone for camcorders priced at $599.
The Holophone H2-PRO is the only patented surround microphone specifically designed for capturing discrete 5.1, 6.1, and 7.1-channels of surround sound for all professional audio applications. It was designed for television and radio broadcasters, film location recording and music producers.
All the H2-PRO’s sound is discrete and in real-time—making it easy to bring into any broadcast or studio environment. Sound can be manipulated, mixed and/or encoded into any/all of the standard consumer playback formats including Dolby, DTS and Circle Surround.
The low-profile PortaMic 5.1 is far more compact and runs on a nine volt battery. It captures discrete 5.1 audio and requires a Dolby PLII consumer encoder for playback. It has a stereo output with both mini plug and mini XLR. Audio can be decoded back to 5.1 channels in post using the Holophone D-Code box or any Dolby PLII decoder.
Holophone’s D-Code device, also priced at $599, works with both the PortaMic 5.1 and the H4 SuperMINI, a higher-end mic priced at $1,999.95. The H4, also a camera-mounted model, features on-board multichannel preamp, virtual surround headphone monitor and encoder. It enables on-camera surround sound capture from multiple points and perspectives.
Though Holophone has been alone in this segment of the market for years, new competition is about to emerge. DPA is about to introduce its 5100 mobile surround microphone. It was shown first at the IBC show last year and is slated for delivery at about this time. No price has yet been set, but it’s expected to be over $3,000.
The 5100 can be mounted on a camera or microphone stand, suspended or handheld, and requires no additional signal processing. It’s lightweight, portable, robust and highly resilient to inclement weather conditions.
The microphone employs five miniature pressure transducers that exhibit low sensitivity to wind and mechanical noise, low distortion, consistent low frequency response and wide dynamic range.
Optimum channel separation and directionality are achieved through a combination of DPA’s DiPMic (Directional Pressure Microphone) technology, which mounts interference tubes on the L/C/R capsules, and the use of acoustic baffles that preserves the accuracy of levels between the discrete analog output channels.
The 5100’s three front microphones are time coincident to eliminate comb filtering and to ensure frequency consistency when downmixing to stereo or mono. In contrast, the rear microphones, which feature standard omnidirectional patterns, are optimally spaced from both each other and the front array to simulate natural time arrival differences. The LFE channel is comprised from a L/R sum, which is then attenuated 10 dB in comparison with the signal from the main channels.
In a more traditional design, Sanken’s WMS-5 professional field microphone offers five channel surround capturing from what appears to be a standard shotgun microphone body. Dual M-S stereo capsules are used to maintain precise phase-coherence and accurate surround audio reproduction.
The Sanken features five discrete balanced XLR output connectors and M-S to left/right stereo matrix circuitry in the microphone body. Weighing only 8.28 ounces, the microphone can easily be camera-mounted. It has five XLR output connectors and various accessories for outdoor shooting. List price is $4,195.
Surround microphones for camcorders remain expensive, especially for the most professional level models. However, prices have dramatically decreased since their introduce. Historically, standard definition video cameras were over $55,000 only 30 years ago. Today’s HD model camcorders are substantially cheaper than ever before.
The real question is whether sound will continue to remain the poor stepchild to video. For premium productions, that question has already been answered. For lower and medium cost productions, it remains on the table.
In the era of high-definition, surround sound is a good way to differentiate of program. On this questions there is no argument.