SPS422B Microphone System

What is it?

The SoundField SPS422B is a unique microphone that applies the SoundField concept to Stereo, Mid/Side and surround applications. In its most basic form, it is a mono and variable angle stereo Microphone with remotely variable pick-up patterns plus the option to deliver Mid/Side and B-Format outputs. The SPS422B System consists of two parts that are used together, a SoundField microphone and an AC powered 1U SoundField Processor.

What makes it different?

The SoundField microphone itself contains four capsules, mounted in a tetrahedral array (tetrahedral describes an equilateral triangle). This tetrahedral capsule array, combined with its dedicated 1U processor allows the SPS422B to become different kinds of microphones by varying individual capsule combinations. It can be a conventional mono omni, cardioid, hyper-cardioid, figure eight or anything in between. It can be a stereo variable angle omni, stereo cardioid, or stereo figure eight. It can also be a complete Mid/Side system for those with sum/difference matrix decoders.

Perhaps the key advantage of the SoundField system is that unlike separate or even stereo microphones, the error between capsules is resolved within the SoundField Processor. This capsule error is similar to the time arrival error experienced by a listener offset between 2 or more spaced loudspeakers. The benefit in resolving this error is significant in that you can simply "point and shoot" a SoundField microphone regardless of mode. SoundField avoids lengthy set-up time typical of separate microphones and there is no phase cancellation when shifting between mono and stereo modes. Stereo imaging is rock stable and absolutely breathtaking. In addition, the SoundField SPS422B offers variable "stereo width" on a single front panel control which alters imaging without changing the physical set-up.

Multi-channel

When used in conjunction with the Surround Zone software or SP451 Surround Processor, the SPS422B System becomes a powerful self-contained Surround Sound recording package.

How does it work?

The SoundField System relies upon B-Format and its processing at its core. The advantage of B-Format is that everything begins as a phase accurate representation of an acoustical event. Phase accurate means that all sound is recorded from the same central point. This is the core difference between SoundField and traditional stereo or multi-mike set-ups, in that all other methods (other than a single mono mike) capture audio from different points in space. From SoundField's "single point source", any type of output (omni, cardioid, hyper-cardioid or figure eight) in any form (mono, stereo, or extra wide stereo) can be derived. In addition, special output forms such as mid/side are just a push button away. This makes the SoundField SPS422B perhaps the most flexible microphone on the planet, and one that offers a long future.

How do I use it?

SoundField is used as a normal mono omni microphone in that you just set it on a stand and go. Moving the microphone around can vary the relationship between ambient and direct sound, so some experimentation with placement is likely. It can be pointed directly at the source like a shotgun microphone (end fire mode), hung upside down from a boom (invert mode) or set on a stand like an ordinary mike. The 1U processor is ideally situated next to the user, connected to the mic via a supplied 20 metre SoundField cable (longer lengths available), so pattern, stereo angle (width) and all mic parameters can be changed and the result monitored with headphones or in the control room.

SoundField advantages

1) Only a SoundField acts as a "single point source", all but eliminating phase error between capsules, making it backward compatible down to stereo or mono without cancellations in response.

2) As a small "handheld size" integrated multi-capsule microphone, it offers ease of handling and mounting compared to traditional stereo and surround set-ups, making recording a "point and shoot" process.

3) Variable Pattern control, stereo Width and all other mic parameters can be adjusted by the user on the front panel of the 1U processor which can be situated up to 100 metres from the mic.

How does it sound?

While SoundField specializes in imaging, it is no less effective in the studio or the field for faithfully recording the sound exactly as it is without additional bass or high frequency. The SPS422B is a true "flat" performance microphone system free of sharp peaks or dips, bumps in response that change the tone of the real event. It is designed to be flat in distant miking situations and is often considered "warm" in close miking. It is ideal as a room mike, on drum overheads, for piano, larger vocal groups and all acoustic instruments.