RDL RM-MP12A Quick Start Guide

RM-MP12A

Rack Mount 12-Channel Audio Monitor Panel

• Twelve Individually Selectable Audio Inputs Using High Quality Keyboard-Style Pushbuttons

• Selectable Operating MODE Provides Interlocking Source Selection or Mixing Multiple Sources

• LED Above Each Button to Show Selected Source

• Variable Intensity VU Ballistic LED Provided Above the Button for Each Audio Input

• Rear-Panel Switches Set Each Input Level Range for +4 dBu, 25 V, 70.7 V or 100 V

• Input Signals May Be: Balanced, Unbalanced, Constant Voltage Speaker Line or 8 Ω

• Installer Adjustable Trimmers Permit Calibrating Each Input for Normal Operating Levels In the Selected Range

• Calibrated Front-Panel Meter Displays Selected Audio Source

• Meter Calibrated to 0 dB Scale, with Full Metering Above and Below 0 dB

• Meter Scale: -18, -10, -8, -6, -4.5, -3, -2, -1, 0, +1.5, +3, +6, +10, +14, +18

• Front-Panel Speaker and Headphone Jack

• Level Control for Speaker and Headphone Uses VCA for Long, Noise-Free Life

• Internal 4.5 W RMS Power Amplifier Feeds Either Internal Speaker or External Speaker

• Fixed Line-Level +4 dBu Output

• Variable Line-Level +4 dBu Output (Controlled by Front-Panel Knob)

• Audio Inputs and Outputs on Plug-In Terminal Blocks

• Differential Inputs Feature Very High Common Mode Rejection for Minimum Hum

Wherever monaural line level or speaker level audio needs to be selected and/or monitored economically with professional quality,
reliability, and in a single rack unit, the RM-MP12A is the ideal choice. Use the RM-MP12A individually, or combine it with other RDL
products as part of a complete audio/video system.

APPLICATION: The RM-MP12A is the ideal choice in rack mount audio monitoring or source selection applications where various
audio levels need to be selected and/or monitored. Each input may be individually calibrated for unbalanced consumer, balanced
professional, 8 Ω speaker line or constant voltage speaker lines. There is a variable intensity LED on the front panel for each input
(full intensity at 0 dB to minimal intensity at –15 dB). These simple meters remain active at all times providing an immediate visual
indication of correct operating levels for all inputs simultaneously. Front-panel pushbuttons select one of the twelve inputs to feed the
calibrated meter, front-panel speaker (or external speaker if connected) and headphone jack. The 0 dB LED on the calibrated meter
indicates a +4-dBu output at the fixed level output. Normal operating levels in distributed speaker systems are typically less than full
power (for example, normal operating level may be several dB less than 70.7 V or 100 V). A rear-panel calibration control is
provided for each of the twelve inputs permitting each individual level to be calibrated to 0 dB on the meters. With the input level set,
the variable intensity LED for a given input will indicate the same level as the expanded scale meter indicates when that source is
selected.

The front panel features 12 high-reliability, keyboard-style pushbuttons with corresponding LED indicators to show which audio
source is selected. In the MIXING mode, each button alternately selects and deselects an audio source. Multiple sources may be
selected at the same time. In the INTLK (interlocking) mode, pressing a button selects the corresponding source and deselects all
other sources. If the button for an active source is pushed, all audio sources are turned off until the next source selection is made.
The front-panel volume knob controls the audio level of the front-panel headphone jack, front-panel speaker, external speaker output
and variable line level (+4 dBu) rear-panel output. A separate fixed +4-dBu line-level output on the rear panel is always active and
unaffected by the front-panel control. The front-panel control uses a VCA for long-life, noise-free performance. During installation of
the RM-MP12A, either the front-panel speaker or external speaker is selected. Inserting headphones into the front-panel jack will
optionally (based on rear-panel switch setting) mute the speaker.

RDL • 659 N. 6th St. • Prescott, AZ., USA 86301 • [phone] • FAX [phone] • www.rdlnet.com

RM-MP12A

Rack Mount 12-Channel Monitor Panel

Installation/Operation

EN55103-1 E1-E5; EN55103-2 E1-E4

Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.

Use Connection for

External 8 Ohm Speaker

Set Fully Counter

Clockwise for Input

Calibration (Meter

0dB = 70.7V).

Increase Gain for

Lower Input Levels

Set Fully Counter

Clockwise for Input

Calibration (Meter

0dB = 100V).

Increase Gain for

Lower Input Levels

Set Fully Counter

Clockwise for Input

Calibration (Meter

0dB = 25V).

Increase Gain for

Lower Input Levels

Set Fully Counter

Clockwise for Input

Calibration (Meter

0dB = +4 dBu).
Increase Gain for
Lower Input Levels

8 Ohms @ < 100 Watts

8 Ohms @ 100 to 500 Watts

8 Ohms @ 500 to 1200 Watts

Set Jumper to use

Internal Speaker

GAIN

BAAB

INPUT 11INPUT 12

GAIN

GAIN

BAAB

INPUT 9INPUT 10

GAIN

GAIN

BAAB

INPUT 7INPUT 8

GAIN

GAIN

BAAB

INPUT 5INPUT 6

GAIN

GAIN

BAAB

INPUT 3INPUT 4

GAIN

GAIN

INPUT 2 INPUT 1

GAIN

BAAB

SIGNAL

FROM

70V

SPEAKER

LINE

SIGNAL

FROM

100V

SPEAKER

LINE

SIGNAL

FROM

25V

SPEAKER

LINE

SIGNAL

FROM

BALANCED
LINE-LEVEL

SOURCE

SIGNAL

FROM

UNBALANCED

LINE-LEVEL

SOURCE

SIGNAL FROM

8 OHM SPEAKER

REFER TO

DIAGRAM ABOVE FOR

SWITCH SETTINGS

100 VOLT
70 VOLT
25 VOLT
+4 LINE

BA

INPUT CALIBRATION

WITH GAIN TRIMMER CW

Use the Fixed (+4 dBu) and/or Variable
(controlled by front-panel level control)

Line-Level Outputs to Feed External Power

Amplifiers or Other Line-Level Equipment

FIXED OUT VAR OUT 24VDC IN

AMP
OUT

SPKR

the NORM position.

24VDC IN

RDL

INTLKMIXING

NORM MUTE

MODE SPEAKER

INTRNL

Set the SPEAKER switch to mute the
Internal or External Speaker (MUTE)
when the Headset Jack is being used.

Headset does not mute the speaker in

Set MODE switch to MIXING to ena bl e

simultaneous selection of multiple sources. Set

MODE switch to INTLK to enable only one

source at a time. Unit must be repowered for

new switch position to become effective.

MADE IN U.S.A.

TYPICAL PERFORMANCE

Inputs (12): +4 dBu, 25 V, 70.7 V, 100 V, 8 Ω (set by rear-panel switches)
Input Level: -11 dBu to +9 dBu (+4 dBu input)

25 V, 70.7 V, 100 V (calibrated with gain trim set fully counter-clockwise)
Headroom: > 18 dB (above calibrated input level)
Gain: 0 dB to 20 dB (Adjustable for speaker-level input, 25-turn trim potentiometer)

-5 dB to 15 dB (+4 dBu input)
Frequency Response: 10 Hz to 20 kHz (+/-0.25 dB)
THD+N: < 0.010% (20 Hz to 20 kHz)
Intermodulation Distortion: < 0.025% (20 Hz to 20 kHz)
Channel to Channel Crosstalk: < -80 dB (10 Hz to 20 kHz)
Residual Noise: < -80 dB (Channel ON; referred to +4 dBu)
OFF Attenuation: > 80 dB (10 Hz to 20 kHz)
Indicators per Channel (2): Red LED above selection button indicating active channel;

Variable intensity LED above the button for each audio input indicates audio level

(minimum intensity at –15 dB, maximum intensity at 0 dB)
CMRR: > 75 dB (50 Hz to 120 Hz)
Outputs (4): 150 Ω, +4 dBu fixed level (balanced or unbalanced via plug-in terminal block)

150 Ω, +4 dBu variable level

(balanced, controlled by front-panel volume control)

4.5 W RMS external speaker connection

(use of external speaker disconnects internal speaker)

100 mW ¼-inch stereo headphone jack
Power Requirement: 24 to 33 Vdc @ 700 mA, Ground-referenced
Mounting: Standard 19” Rack-mount; 1 Rack Unit (RU)
Dimensions: Height: 1.75 in. 4.4 cm
Length: 19.0 in. 48.3 cm
Depth: 5.35 in. 13.6 cm

891-1065C

Radio Design Labs Technical Support Centers

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

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