Neumann Digital Mic:
Portent Of Things To Come?

(Editor's Note: We recently received the following press release. While it discusses a studio product, I thought it interesting as a possible portent of future products for installed and live system applications. Also keep in mind that this is a press release and I've done my best to eliminate the "bigger better best" verbiage while retaining as many relevant specifics as possible. - Keith)

At AES 2001 Neumann will be introducing the Solution-D digital microphone system. Solution-D consists of three components: digital microphone (model D-01), digital microphone interface (model DMI-2),and software that permits operation and remote control of the microphone. The system conforms to the new Standard AES 42-2001.

D-01 Microphone
An A/D converter specifically for the mic’s capsule signal level is positioned right behind the capsule. Without any of the pre-amplification that is standard in analog microphones, the signal transduced by the capsule is immediately converted into the digital domain. The result is an internal digital 28-bit signal with a dynamic range of more than 130 dB (A-weighted, microphone capsule included).

An FPGA (Field Programmable Gate Array) built into the microphone helps process the digital signal, meaning the D-01 can digitally implement and remote control such parameters as polar pattern pre-attenuation, low-cut, pre-amplification and various switching functions.

The microphone also includes a three-pin XLR jack through which the supply voltage, phantom power, and remote control data stream are transmitted. This data protocol also contains the signal components of a control loop as required for synchronous transmission.

DMI-2 Interface
Solution-D microphones connect directly to any device that supports the new AES 42-2001 Standard. In all other situations, the DMI-2 interface is necessary.

This separate, two-channel device converts the AES 42-2001 data format of the microphone into an AES/EBU signal. Neumann remote control software running on a laptop or desktop computer and connected to the DMI-2 interface via USB connection will operate the system. If a large number of microphones are used, it is possible to cascade multiple DMI-2s and still provide each interface with an individual address.

Besides word-clock input and output, the unit also has an integral master word clock generator that will support sample rates of up to 192 kHz in the future.

If there is no word clock at the input, then the DMI-2 automatically uses the internal master to synchronize both microphone channels. The unit supplies either the externally or internally derived sample rate as a time
reference at the word-clock output. Users can control external commands, such as a red "ON AIR" light, from a nine-pin user port.

Software
Remote control software operates the digital microphone. Ideally, this software would run as one component in a recording system, but it can also run by itself on a stand-alone desktop or laptop computer.

The software displays every important parameter on the screen and allows a user to change a given parameter at any time. The parameters shown include polar pattern pre attenuation, low-cut, pre-amplification, various indicators of microphone status, command indicators, and mute and phase reverse functions.

It is also possible to follow signal levels on the screen. During production, the recording engineer has complete control over the status and parameters of all microphones and can change settings if necessary.

In addition to the above-mentioned "functional" parameters, the software displays additional information transmitted by the microphone, such as manufacturer name, type, and serial number for use in positive self-identification of the microphone connected.

Moreover, it is possible to add self-written notes (e.g. the name of the sound source and microphone position). It is also possible to store and retrieve the setup for an entire recording session.

"One of the last parts of the audio chain has yet to become part of the digital revolution - the microphone." observes Karl Winkler of Neumann/USA. "At Neumann we have been developing a new platform over the past three years. We believe this system will likely be the beginning of an industry wide change in terms of how microphones are perceived as part of the overall picture."