Orban OPTIMOD-FM 5518

FM Limiter

Orban OPTIMOD-FM 5518 is a superb stand-alone stereo FM limiter combining look-ahead and bandlimited clipping techniques.

SKU: 101432



Orban OPTIMOD-FM 5518

Precision Stand-Alone Stereo Encoder

Orban OPTIMOD-FM 5518 is a superb high-quality stand-alone stereo encoder combining look-ahead and band-limited clipping techniques to control STL-induced overshoots while minimizing artefacts.

Orban’s all-digital 5518 FM Stereo Encoder operates at 64 kHz to 512 kHz sample rates and offers lowpass filtering, left/right-domain overshoot limiting, composite limiting, diversity delay and an ITU BS.412 multiplex power controller.

The 5518 is compatible with all Orban OPTIMOD-FM processors, including the 2200, 2300, 5300, 5500, 8000, 8100, 8200, 8300, 8400, 8500 and 8600.

It is also compatible with most other processor brands.

An LCD and full-time LED meters make setup, adjustment and programming of the 5518 easy — you can always see the metering while you are adjusting the processor.

Navigation is by dedicated buttons, soft buttons (whose functions are context-sensitive), and a large rotary knob.

The 5518’s patented “Half-Cosine Interpolation” composite limiter provides full spectral protection of subcarriers and RDS/RBDS regardless of the amount of composite limiting.

The built-in, defeatable ITU BS.412 multiplex power controller acts on all outputs to meet even the most stringent European government regulations.

A 10 MHz frequency reference input allows the stereo pilot tone frequency to be locked to GPS or another high-accuracy frequency standard.

This improves the performance of single-frequency networks in areas where coverage of the transmitters overlaps.

The 5518 uses the same preset logic as other OPTIMOD-FMs and should be familiar to users of the OPTIMOD-FM family of products.

Because the 5518 is a dedicated stereo encoder, it comes with only one Factory Preset, which allows you to set up the parameters of the stereo encoder.

Normally, when you have finished setting up the 5518 by editing its Factory Preset, you will then save the result as a User Preset.

You can save many different customized settings as different User Presets.

Input/Output Configuration

The 5518 simultaneously accommodates:

Digital AES3 left/right inputs and outputs.

  • Analog left/right inputs and outputs.
  • Composite stereo outputs.
  • Input/Output Configuration

The left/right analog and digital outputs can be flat or pre-emphasized and emit the output of the left/right overshoot limiter. This allows the peak-controlled output of the 5518 to drive an STL conveying audio to a second FM transmitter, translator or booster.

Input/Output Configuration

Subcarrier (SCA and RDS/RBDS) inputs.

A sync reference input that can accept 10 MHz or 1 x wordclock (32, 44.1, 48, 88.2 and 96 kHz) and lock the digital output sample rate and the 19 kHz pilot tone frequency to this input.

The 5518 can be remote-controlled by 5 to 12 V pulses applied to eight programmable, optically-isolated “general-purpose interface” (GPI) ports available at the REMOTE INTERFACE connector.

The 5518 is the ideal choice for network broadcasters who process with an FM audio processor at the network origination point.

It is also useful when the connection to the studio is through an STL using lossy compression that introduces overshoots.

Using phase-linear filters, the 5518 can precisely control the audio bandwidth to 15, 16 or 17 kHz, user-selectable.

You can select the bandwidth to prevent overshoots in uncompressed digital links operating at 32 or 44.1 kHz sample rate.

All bandwidths protect the pilot tone and RDS (or RBDS) subcarrier(s) from interference.


5518 PC Remote software is a scalable graphical application that runs under Windows 2000, XP, Vista and 7. It communicates with a given 5518 via TCP/IP over modem, direct serial and Ethernet connections.

5518 PC Remote software is a scalable graphical application that runs under Windows 2000, XP, Vista and 7. It communicates with a given 5518 via TCP/IP over modem, direct serial and Ethernet connections.

5518’s software can be upgraded remotely through its serial port or Ethernet port, or locally (by connecting a Windows® computer to its serial port through the supplied null modem cable) and running Orban-supplied downloadable upgrade software.