Handbook for Sound Engineers

Microphones 557

16 bits. The microphone is powered directly from the

5 Vdc USB output.

The MXL.006 USB is a cardioid condenser micro-

phone with a USB output that connects directly to a

computer without the need for external mic preamps

through USB 1.1 and 2.0, Fig. 16-142.

The analog section of the MXL.006 microphone

features a 20 Hz–20 kHz frequency response, a large

gold diaphragm, pressure-gradient condenser capsule,

and a three-position, switchable attenuation pad with

settings for Hi (0 dB), Medium (5 dB), and Lo

(10 dB). The digital section features a 16-bit Delta

Sigma A/D converter with a sampling rate of 44.1 kHz

and 48 kHz. Protecting the instrument’s capsule is a

heavy-duty wire mesh grill with an integrated pop filter.

The MXL.006 includes a red LED behind the protec-

tive grill to inform the user that the microphone is active

and correctly oriented. The MXL.006 ships with a travel

case, a desktop microphone stand, a 10 ft USB cable,

windscreen, an applications guide, and free download-

able recording software for PCs and Mac.

16.10 Wireless Communication Systems

Wireless communication systems are wireless micro-

phones (radio microphones), Fig. 16-143, and a related

concept, wireless intercoms. Often the same end user

buys both the microphones and intercoms for use in

television and radio broadcast production, film produc-

tion, and related entertainment-oriented applications.

Wireless microphone systems can be used with any

of the preceding microphones discussed. Some wireless

microphone systems include a fixed microphone

cartridge while others allow the use of cartridges by

various manufacturers.

A block diagram of a wireless microphone system is

shown in Fig. 16-144. The sending end of a wireless

microphone system has a dynamic, condenser, electret,

or pressure zone microphone connected to a preampli-

fier, compressor, and a small transmitter/modulator and

antenna.

The receiving end of the system is an antenna,

receiver/discriminator, expander, and preamplifier,

which is connected to external audio equipment.

In a standard intercom system, each person has a

headset and belt pack (or equivalent), all intercon-

nected by wires. Wireless intercoms are essentially

identical in operation, only they use no cable between

operators. Instead, each belt pack includes a radio trans-

mitter and receiver. The wireless intercom user typically

Figure 16-141. audio-technica AT2020 USB microphone.
Courtesy Audio-Technica U.S., Inc.

Figure 16-142. MXL.006 USB microphone. Courtesy
Marshall Electronics, Inc.

Figure 16-143. Shure UHF-R Wireless Microphone System.

Courtesy Shure Incorporated.