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Matrix

Matrix Rack

Overview

Matrix Rack is compatible via POTS and ISDN with all Comrex codecs as well as those from nearly everyone else. It’s also perfect for receiving GSM feeds from the Matrix Portable. Combining the most practical user features with Comrex’s technology advancements, it ensures you get the best performance from your Comrex remote gear.

In its compact, single rack space enclosure, Matrix Rack is delivered equipped to handle full duplex audio, with up to 15 kHz audio bandwidth, over standard dialup POTS. Audio quality scales automatically to compensate for poor phone lines, keeping you connected and on the air.

Program and cueback can be sent over the same phone line. This is a real advantage when off-air monitoring is delayed from real-time, such as with HD Radio or when using a profanity delay.

When the Matrix GSM Module is used in the field, Matrix Rack, connected to a standard POTS landline, delivers 7 kHz broadcast-quality audio.

Install the Matrix Rack ISDN Module when ISDN is available in the field, rather than investing money and studio space in an additional codec. With MPEG Audio Layer III, G.722 and Comrex’s Turbo G.722, the Matrix Rack ISDN Module lets you select the most appropriate combination of fidelity, compatibility and low delay for your needs.

If you already own remote codecs from another manufacturer, Matrix Rack’s compatibility with most of those products can help standardize your operations, reduce chances of operator error and improve your audio remotes.

When you purchase Matrix Rack, you can be confident that you are using the most adaptable and reliable broadcast equipment.

Doing a remote? Put Comrex on the line.


Features & Benefits

Audio quality

Comrex audio coding algorithms are uniquely suited to the task of moving high-quality audio along narrow data channels. Hardware is designed to exceed broadcast audio quality expectations.

POTS:

  • Full duplex FM quality (15 kHz) audio bandwidth at connect rates of 24 kbps and above.
  • Full duplex audio scales from 12 kHz to 5 kHz at connect rates of 21.6 kbps to 9.6 kbps.
  • Selectable “Voice Mode” allows 7 kHz audio with a 300 bps ancillary data channel and extra forward error correction.

GSM:

  • Up to 7 kHz on bit rates as low as 9600 kbps with fewer digital artifacts.

ISDN:

  • MPEG Audio Layer III—15 kHz mono over a single ISDN B channel.
  • G.722—7.5 kHz mono, low delay over a single ISDN B channel.
  • Comrex Turbo G.722—15 kHz mono, low delay over two ISDN B channels.

Line connection reliability

Dialup telephone networks can be unpredictable. Comrex combines our years of experience and the latest technologies to keep you in control of your remotes.

  • Automatic modem negotiation connects at the optimal rate supported by telephone connection.
  • Phone line quality is monitored continuously and modem renegotiates if the line degrades during the call. Renegotiation may be disabled to prevent dropouts at inconvenient times.
  • Maximum data rate can be preset manually to provide a guardband against line errors.
  • A brief two-second renegotiation can be forced manually by pressing a single button on either end of the call.

Easy-to-use dialing and configuration interface

Useful features that nontechnical personnel can readily understand save you time and money on training, preparation and configuration.

  • Quick-dial stores 20 phone numbers in nonvolatile memory.
  • One-touch redial.
  • Auto-answer (on first or sixth ring) and manual answer.
  • POTS connection works with external phones, for PABXs and operator-assisted calls.
  • Accepts dialing strings of up to 44 digits with pauses.
  • Menu-selectable dialing parameters of analog telephone protocols for 20 countries.
  • LCD displays modem connection speed.

Built for the real world

Comrex has addressed all the details to make operation and maintenance of your codec hassle-free.

  • Compatible with all Comrex POTS codec models. (A corresponding unit is required at the other end of the phone line.)
  • Professional broadcast design for years of trouble-free use.
  • Software may be updated through the multipurpose data port and files downloaded from Comrex website or obtained via e-mail. All software updates are free.
  • Switching power supply works everywhere.
  • Backlit LCD display.

Audio mixing and other features

  • Balanced XLR line level audio input—adjustable level.
  • Balanced XLR line level audio output—adjustable level.
  • Built-in peak limiter.
  • Front-panel LED status indicators:
    • — Ring/carrier detection LED fl ashes when an incoming call is ringing and is steadily on when the internal modem is connected with a compatible codec on the far end.
    • — Ready indicator illuminates when decoder locks with far-end compatible codec.
  • Telephone line and telephone set: RJ-11 6-pin modular jacks (two).
  • Four contact closures for remote control:
    • One latching output, enabled upon the decoder synching with far-end codec.
    • One momentary output, activated by a button press on the far-end codec.
    • One momentary input that activates a corresponding contact closure output on the far-end codec. (Performs same function as front-panel “CC” button.)
    • One momentary input that initiates dialing of a preselected, stored telephone number. May be used for applications such as backup studio-transmitter-link.
  • A “CC” key on the Matrix triggers a contact closure on the far end Comrex codec.

Matrix Rack Add-ons

Matrix Rack ISDN Module (optional)

The Comrex Matrix Rack ISDN Module converts your Matrix into a full-featured ISDN codec.

  • Three algorithms are offered in the Matrix ISDN Module to transport mono audio, including G.722 for widest compatibility, Turbo G.722 for very low delay 15 kHz operation and MPEG Audio Layer III for compatibility plus full fidelity at lower bit rates.
  • Includes ability to deliver MPEG Audio Layer III in one direction with a G.722 return for reduced delay on Layer III feeds.
  • Worldwide ISDN interfaces are present in the module, including an international terminal adapter with both “U” and “S/T” interfaces available.
  • Compatible with Comrex’s Matrix Portable (with Matrix Portable ISDN Module), Nexus Rack and Nexus Portable as well as ISDN codecs from most manufacturers.
  • Up to 10 line configurations may be stored in nonvolatile memory.
  • Very easy to program through the intuitive front panel interface.
  • An ancillary data channel provides 1200 baud, bidirectional data on the same ISDN channel used for the coded audio with little impact on audio quality. Allowing devices on both sides of the remote to communicate with each other, ancillary data are available in both MPEG Audio Layer III and G.722 modes, but are limited to the G.722 direction when operating in split mode.
  • LED NT1 status indicator.

Pairing Matrix Rack with remote codecs

Matrix Rack requires a compatible codec on the remote side of the connection.

Matrix Rack mode Paired device requirements
POTS Codec
  • Comrex Matrix Portable connecting via POTS or GSM
  • All other Comrex POTS codecs: BlueBox, Vector and HotLine
  • Selected POTS codecs by other manufacturers
ISDN using MPEG Audio Layer III
  • Comrex Matrix Portable with Matrix Portable ISDN Module
  • All ISDN codecs that support MPEG Layer III
ISDN using G.722
  • Comrex Matrix Portable with Matrix Portable ISDN Module
  • All other Comrex ISDN Codecs: Nexus Rack, Nexus Portable, Envoy and DXR.1
  • All ISDN codecs that supports G.722
ISDN using Comrex Turbo G.722
  • Comrex Matrix Portable with Matrix Portable ISDN Module
  • All other Comrex ISDN Codecs: Nexus Rack, Nexus Portable, Envoy and DXR.1

Matrix Rack Specifications

All specifications are subject to change

Audio connections

  • Balanced XLR line-level audio input—adjustable level
  • Balanced XLR line-level audio output—adjustable level

Other connections

  • Telephone line and telephone set: RJ-11 6-pin modular jacks (2)
  • Contact closures: 2-conductor mini-jacks (4)
    • One latching output, enabled upon the decoder synching with far-end codec
    • One momentary output, activated by a button press on the far-end codec
    • One momentary input that activates a corresponding contact closure output on the far-end codec (performs same function as front-panel “CC” button)
    • One momentary input that initiates dialing of a preselected, stored telephone number. May be used for applications such as backup studio-transmitter-link
  • Auxiliary data port: DB-9
  • Power: 3 conductor IEC

Audio levels

  • Audio input level: selectable -10, 0 and +4 dBu @ 20 KΩ (via jumper to +8 dBu)
  • Audio output level: selectable -10, 0 and +4 dBu @ 100Ω (via jumper to +8 dBu)

Audio Performance

  • POTS:
    Audio performance varies with phone circuit conditions
    • Full duplex FM quality (15 kHz) audio bandwidth at connect rates of 24 kbps and above
    • Full duplex audio scales from 12 kHz to 5 kHz at connect rates of 21.6 kbps to 9.6 kbps
    • Selectable “Voice Mode” allows 7 kHz audio with a 300 bps ancillary data channel and extra forward error correction
  • GSM:
    Audio performance varies with phone circuit conditions
    • Up to 7 kHz on bit rates as low as 9600 kbps with fewer digital artifacts
  • ISDN:
    • MPEG Audio Layer III–15 kHz mono over a single ISDN B channel
    • G.722–7.5 kHz mono, low delay, over a single ISDN B channel
    • Comrex Turbo G.722–15 kHz mono, low delay, over two ISDN B channel

Coding Delay

Delay specified does not include transmission delay

  • POTS: 100 ms
  • GSM: 120 ms (Note: GSM transmission delay may be significant)
  • ISDN
    • G.722 and Turbo G.722: 6 ms
    • MPEG Audio Layer III: 310 m

Power and physical

  • Internal supply: 120/240 VAC 60/50 Hz
  • Size: 1U Rack 19" W x 8" D x 1.75" H (48.25 cm x 20.3 cm x 4.5 cm)
  • Weight: 5.5 lbs (2.5 kg)

Matrix Rack ISDN Module

Connections

  • ISDN line connection: RJ-45
  • External DCE port: DB-9 pin connector allows bypass of the internal terminal adapter to connect to an external terminal adapter, DSU, satellite terminal, etc.

Levels

  • Ancillary data: RS-232
  • DCE in/out: RS-422

Physical

  • Powered through Matrix Rack
  • Size: 3.5" W x 7.5" D x .75" H (8.9 cm x 19 cm x 1.9 cm)
  • Net weight: 0.4 lbs (0.2 kg)
  • Housed within Matrix Rack

 

For more details and specifications, please see see the Matrix Detail Book. For more information on GSM, please see Tech Note 209 - Wireless Remotes.