Solution-D Digital Microphone Technology from Neumann
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(Click for a close-up) |
June 13, 2001
This year at the AES 2001, Neumann will unveil Solution-D, a new generation of digital microphones. With Solution-D, Neumann has succeeded in transferring the dynamic range and fidelity of the best analog studio microphones into the digital domain, thus closing the final gap in the all-digital signal path.
Owing to a revolutionary new A/D conversion process, a specially developed synchronization method, and remote control of typical microphone parameters and mixing console functions, Solution-D satisfies even the highest demands of professional audio production. Neumann will unveil the first product in the Solution-D digital microphone family at AES. It consists of three components: the Digital Microphone D-01, the Digital Microphone Interface DMI-2, and the software that permits operation and remote control of the microphone. The system conforms to the new Standard AES 42-2001.
"One of the last parts of the audio chain has yet to become part of the digital revolution - the microphone." observed Karl Winkler, of Neumann/USA. "At Neumann however, we have been developing a new platform over the past three years. Solution-D is a new direction for us, a truly revolutionary product that will change the face of the recording arts for the better. Based on the new AES 42-2001 standard, 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."
The D-01 Microphone
At first glance, the D-01 microphone looks just like its analog counterparts. However, an A/D converter specially developed and optimized by Neumann for the microphone capsule's signal level sits right behind the capsule. Without any of the preamplification 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 right into the microphone will help process the digital signal. This means that the D-01 can digitally implement and remote control such parameters as polar pattern, pre-attenuation, low-cut, pre-amplification and various switching functions. Ultimately, Solution-D eliminates the need for analog microphone preamplifiers and A/D converters.
The microphone houses 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. Output conforms to the AES 42-2001 data format.
Digital Microphone Interface DMI-2
Solution-D microphones connect directly to any device that supports the new AES 42-2001 Standard. In all other situations, the Neumann Digital Microphone Interface DMI-2 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 a 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.
Remote Control 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 quickly and conveniently 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). Of course, it is also possible to store and retrieve the setup for an entire recording session. For more information, visit their web site at www.neumann.com. | 
