RDL RU-SM16D Datasheet



RACK-UP® SERIES

Model RU-SM16D

Quad Audio Meter

 Precision Audio Level Metering
 Digital 16 LED String Display Indication
 Four Mono Meters or Dual Stereo Metering
 Selectable Fixed or Variable Calibration
 Individual Channel Calibration Controls
 Selectable Peak or Average Metering
 Peak-Hold Display for +10, +14, +18 dB
 Line-Level, Speaker-Level or 25V/70V/100 V

Audio Input

The RU-SM16D is part of the group of RACK-UP products from Radio Design Labs. RACK-UPs feature the advanced circuitry for which RDL
products are known, combined with accessible user-friendly controls and displays. The ultra compact design permits high-density installations,
with three products mounted in a single rack unit! Single RACK-UPs can be mounted right where they are needed using the adhesive method
popularized by RDL’s STICK-ON
surface!

APPLICATION: The RU-SM16D is a four channel audio meter that measures and displays line-level audio, constant

voltage or low impedance amplified audio level. Each meter provides either fixed or variable calibration and displays
in either peak or VU style average mode.

Each input accepts balanced or unbalanced line-level audio, or amplified audio from a low impedance (4 Ohm or 8
Ohm) or constant voltage (25 V, 70 V, or 100V) power amplifier. Rear-panel input range switches match the meter
gain and calibration to the input source. Inputs are connected through a detachable terminal block.

A rear-panel switch sets the input calibration to FIXED or VARIABLE. In the FIXED setting, 0 dB on the meter
corresponds to the input range switch setting of +4 dBu, 25 V, 70 V or 100 V. In the VARIABLE position, the
front-panel trimmers are active, permitting the 0 dB meter LED to be calibrated to average signal levels as much as
20 dB below the FIXED calibrated value.

Each meter ballistic is set using a rear-panel switch. In the PEAK setting, the meter responds to audio peak content.
In the AVERAGE position, the meter displays the average audio level following VU time constants. In either mode the
upper three LEDs (+10, +14, +18) remain in the PEAK HOLD mode.

In mono installations, it may be advantageous to feed the mono source to two meters, setting one for peak and the
other for average. In stereo installations, each channel can feed two of the four meters, permitting both peak and
average metering of each channel. When monitoring constant voltage installations, one meter may be fed directly
from the output of the amplifier while the next meter is fed from a return cable at the end of the speaker line run. This
provides an instant visual verification of continuity through two public address systems. Each meter in the
RU-SM16D can monitor separate audio sources. With adjacent mounting of three RU-SM16Ds, 12 channels of
audio can be precisely monitored in a single rack unit.

The flexible range of input signals, vibrant visibility, professional appearance, accuracy and mounting possibilities of
the RU-SM16D make it ideally suited to commercial, professional, studio and broadcast applications. Combine the
RU-SM16D with other RDL products as part of an integrated, high quality system.



series of products. Optional brackets permit mounting a RACK-UP module above, below, or in front of any flat

RDL  659 6th St.  Prescott, AZ., USA 86301  [phone]  FAX [phone]

www.rdlnet.com

RACK-UP® SERIES

Model RU-SM16D

Quad Audio Meter

Installation/Operation

Declaration of Conformity available from rdlnet.com.

Sole EMC specifications provided on product package.

Specifications are subject to change without notice.

TYPICAL PERFORMANCE

Inputs (4): Line level or Amplified speaker level
Input Impedance: > 40 kΩ balanced or unbalanced
0 dB Calibration: Fixed or Variable (switch-selectable)
Fixed Input Level: +4 dBu (+4 switch settings, for 0 dB reading)
25 V* (25 V switch settings, for 0 dB reading)
70 V* (70 V switch settings, for 0 dB reading)
100 V* (100 V switch settings, for 0 dB reading)
Variable Input Level Range: -24 dBu to +12 dBu (+4 switch settings, for 0 dB reading)
2 V to 90 V* (25 V switch settings, for 0 dB reading)
4 V to 90 V* (70 V switch settings, for 0 dB reading)
5 V to 100 V* (100 V switch settings, for 0 dB reading)
*Constant-voltage or low-impedance (4 Ohms, 8 Ohms) amplifier output
Metering Freq. Response: 20 Hz to 20 kHz
Indicators: 16 LEDs per channel; SIG, -20, -15, -12, -9, -6, -3, -2, -1, 0, +1.5, +3, +6, +10, +14, +18
(+10, +14, +18 are PEAK HOLD indicators only)
Metering Response: Each channel individually selectable PEAK or AVG (switch-selectable)
Peak Mode Average Mode
Rise Time (10% -us 90%) 50 us 130 ms
Rise Time (0% - 100%) 60 us 300 ms**
Fall Time (90% - 10%) 65 ms 185 ms
Fall Time (100% - 0%) 100 ms 300 ms**
**VU Characteristic

Power Requirement: GROUND-REFERENCED, 24 Vdc @ 450 mA
Ambient Operating Environment: 0° C to 40° C

Radio Design Labs Technical Support Centers

U.S.A. [phone], [phone]; Fax: [phone]

891-3470C

Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287