Audio Level Metering with Sound Devices Field Mixers
This article moves beyond the basics to specifically discuss metering with Sound Devices 442, MixPre, and MP-2 portable products. A good general understanding of audio level metering is helpful before understanding the nuances of Sound Devices meters. Every manufacturer has a unique perspective on how audio level information should be communicated to the user. No matter what type of equipment used, there is a learning curve associated with translating the metered level to real-world applications. In our opinion, peak-responding metering is more appropriate for signal acquisition and recording than VU metering. VU meters are excellent for judging signal loudness — more important in sound reinforcement and mix-down applications. With today's modern inputs, knowing where a signal peaks is essential to the recordist. Sound Devices products present peak information in a consistent, quickly understood format.
Physical Type
There are three commonly used meter types used on portable audio equipment, LED, LCD, and mechanical. Sound Devices has chosen LED-based meters for several important reasons.- LED meters are not affected by ambient temperature conditions, whereas LCD meters often darken in high humidity/heat conditions and slow down in cold climates.
- LED meters are not affected by shock or mechanical vibration like mechanical meters.
- LED meters can be driven with varying voltage to change their intensity.
- LED meters can be viewed easily from a distance.
- LED meters free the mechanical design and allow smaller product size.
302 and 442 Meter Ballistics
The output meter ballistics (speed of response) on both the 302 and 442 can be selected among three settings:- VU - appropriate for music recording,
- Peak - with true PPM decay times,
- Peak/VU combination- the most informative setting.
- Percussive sound sources, 50 dB + peak to average levels,
- Speech, 14 - 25 dB peak to average levels,
- Jam band, 3 - 8 dB peak to average levels .