Symetrix 371

The Symetrix 371 SPL Computer automatically raises and lowers sound system levels in response to changes in ambient noise conditions. Designed for installations featuring foreground music and/or paging, it ensures that music and announcements are always clearly audible and distinct, but never too loud. Proprietary AmbiSense™ technology enables the 371 to continuously monitor changing ambient noise levels—not just during gaps in the audio program—so it can respond quickly to sudden changes.

A simple set of step-through menus displayed on the front panel LCD guides you through setup of the 371. You set the parameters of the acoustic environment and then set the way you want the unit to respond to changes in it. In operation, the 371 tracks environmental noise levels, internal signal levels and all the control settings. It makes appropriate gain changes whenever it finds measured noise levels that deviate from the stored performance characteristics. Menu adjustments determine how much the gain is changed, and how quickly that change occurs.

Simple calibration, precise performance, and value priced. Backed by our 15-year history of SPL processing innovation, the Symetrix 371 offers a complete and affordable solution for audio level management.

Features:

• Uses Microphone for Noise Sensing
• Continuously Monitors Ambient Noise Levels
• Headphone Monitoring Monitor
• 3 Operating Modes Active
• History displays the lowest and highest SPL readings
• Bypass bypasses the gain control
• Signal Path Controls mono or stereo signals
• Easy Calibration Use step-through menus
• Ratio Adjustment
• Sense Signal Monitoring Display

Specifications:

• Maximum Input Level: +20 dBu balanced, +20 dBu unbalanced
• Program Input Impedance: >20 k ohms balanced, >10 k ohms unbalanced
• Input Common Mode Rejection: >40 dB
• Maximum Output Level:
      * +26 dBu balanced (20 k ohm load)
      * +22 dBm balanced (600 ohm load)
• Output Impedance: 200 ohms balanced, 100 ohms unbalanced
• Program Frequency Response: 20 Hz to 20 kHz, +0, –1 dB
• Program Path THD+N: <0.025% (+4 dBu in, +4 dBu out)
• Output Gain Limits: +20, –30 dB
• Sense Channel Frequency Response: –3 dB at 300 Hz and 6000 Hz
• Sense Channel Gain: selectable, 0 dB to +70 dB
• Additional Headphone Monitor Gain: 28 dB maximum
• Program Channel Output Noise: –95 dBu @ unity gain, typical
• Master Output Level Adjustment Range: +/–10 dB internal, +10 dB to –50 dB remote
• Line Inpus, Sense Input, Ducker Control, Remote Gain, Line Output Connectors: Euroblock
• Power In Connector: 7-pin DIN
• Headphone Connector: 1/4 in. TRS, will drive mono or stereo headphones
• Power Requirements: 10 W maximum, Symetrix PS-3 or PS-3E only
• PS-3: 115 V, 60 Hz AC nominal
• PS-3E: 230 V, 50 Hz to 60 Hz AC nominal
• Dimensions (H x W x D): 1.75" x 8.5" x 6.5" (4.44 x 21.59 x 15.88 cm), 1/2 Rack Unit
• Weight: 4.5 lbs. (2.03 kg)