• Download 7BD Mobile App

  • Live Chat


Your #01 Broadcast Provider!

Transmission Transmission

Audio Processors



From: Orban

-User Friendly Interface
-Universal transmitter protection and audio processing
-A built-in RDS/RBDS encoder

Optimod-FM 8600 was a hit as soon as it was introduced. Compared to Orban’s previous flagship, the 8600’s dramatically improved “MX” peak limiter technology decreased distortion while increasing transient punch and high frequency power handling capacity. A significant number of broadcasters have asked us to make the 8600’s sound available in a compact package at a lower price. Orban’s response is the 8600Si, which offers 8600-class sound in a single rack unit. An efficient, switching power supply ensures that the 8600Si runs cool even in a crowded rack. The 8600Si includes simultaneous processing for FM and for digital transmissions like netcasts, DAB+ and HD Radio. 

The 8600Si provides stereo enhancement, equalization, AGC, multiband compression, low-IM peak limiting, stereo encoding, and composite limiting — everything that even the most competitive major market station needs to stand out on the dial. More than 20 excellent sounding, format specific factory presets get you started. You'll find all of your favorite 8500 presets, plus the 8600 "MX" presets designed by Bob Orban and Greg Ogonowski to exploit the exciting possibilities inherent in the 8600Si's peak limiter technology. Although the factory presets are fully competent "out of the box”. You can customize them with easy one-knob LESS-MORE control. Full Control gives you the versatility to customize your audio further. Orban’s Quick setup, which is a guided sequence of screens through the 8600Si‘s setup, is the easiest way to have your station On Air quickly.

Improved Peak Limiter Technology:
Dramatically improved peak limiter technology decreases distortion while increasing transient punch and high frequency power handling capacity. Compared to the FM-channel peak limiter in OPTIMOD-FM 8500, the new peak limiter typically provides 2.5 to 3 dB more power at high frequencies, which minimizes audible HF loss caused by pre-emphasis limiting. Drums and percussion cut through the mix. Highs are airy. "Problem material" that used to cause audible distortion is handled cleanly.  While this design offers about the same loudness as 8500 processing, its main goal is to make FM analog broadcasts more competitive with the cleanliness, punch, and open high frequencies of the digital media against which FM analog transmissions now battle. The FM loudness wars represent 20th-century thinking; in the 21st century, the new competition is digital media. Thanks to its fresh, crisp sound, the 8600Si helps level the playing field between analog FM and its ever more aggressive digital-only competitors.

Diversity Delay:
For Digital Radio broadcasters who prefer using a separate processor for the digital channel, the 8600Si's built-in delay (up to 16 seconds) in the analog processing path vastly improves installation versatility in HD Radio facilities, freeing you from the need to use the delay line built into the Digital Radio exciter. This allows you to use the 8600Si's built-in stereo encoder and composite limiter to drive the analog FM transmitter, ensuring no-compromise analog-channel loudness.

Independent Processing:
The 8600Si’ HD (“Digital Radio”) output is designed to feed streaming, netcasting, and digital satellite or cable radio channels, which can be Eureka 147, DRM, DAB + or the iBiquity® HD Radio system (formerly known as “IBOC”—“In-Band On-Channel”) approved for use in the United States. The equalizer and five-band compressor/limiter in the digital processing chain have their own sets of user-adjustable audio controls that are independent of the controls in the FM analog transmission chain’s equalizer and five-band compressor/limiter. The bottom line? Processing that optimizes the sound of your FM channel while punching remarkably crisp, clean, CD-like audio through to your digital channel audience.

Loudness and True Peak control:
The digital radio and analog radio processing chains offer ITU-R BS.1770-3+ Loudness Meters and Safety Limiters for use in countries that enforce a BS.1770 loudness limit on digital and/or analog radio broadcasts. The 8600Si implements “true peak control” in the HD processing chain by oversampling the HD peak limiter’s sidechain at 256 kHz. This allows the 8600Si to prevent clipping in a playback device’s analog signal path by predicting and controlling the analog peak level follow the playback device’s reconstruction filter to an accuracy of better than 0.5 dB. For typical program material, accuracy is 0.2 dB. Without true peak control, analog clipping can occur even if all peak values of the digital samples are below 0 dBFS. This phenomenon has also been termed “0 dBFS+.” Thanks to true peak control, sample rate conversion, unless it removes high frequency program energy or introduces group delay distortion, cannot cause sample peaks to increase more than 0.5 dB.


-Frequency Response (Bypass Mode): Follows standard 50μs or 75μs pre-emphasis curve ±0.10 dB, 2.0 Hz–15 kHz. Analog left/right output and digital output can be user-configured for flat or pre-emphasized output.
-Noise: Output noise floor will depend upon how much gain the processor is set for (Limit Drive, AGC Drive, Two-Band Drive, and/or Multi-Band Drive), gating level, equalization, noise reduction, etc. The dynamic range of the A/D Converter, which has a specified overload-to–noise ratio of 110 dB, primarily governs it. The dynamic range of the digital signal processing is 144 dB. 
-Total System Distortion (de-emphasized, 100% modulation): <0.01% THD, 20 Hz–1 kHz, rising to <0.05% at 15 kHz. <0.02% SMPTE IM Distortion. 
-Total System L/R Channel Separation: >50 dB, 20 Hz – 15 kHz; 60 dB typical. 
-Polarity (Two-Band and Bypass Modes): Absolute polarity maintained. Positive-going signal on input will result in positive-going signal on output when HD --------Polarity and FM polarity controls are set to POSITIVE. 
-Processing Sample Rate: The 8600Si is a “multirate” system, using internal rates from 64 kHz to 512 kHz as appropriate for the processing being performed. Audio clippers operate at 256 kHz (and are anti-aliased), while the composite limiter operates at 512 kHz. 
-Peak Control at HD Output: The peak limiter is oversampled at 256 kHz, yielding a worst case overshoot of 0.4 dB at the analog output and for all output sample rates. (To achieve this performance at 32 kHz output sample rate, it is necessary to set the 8600Si’s HD lowpass filter cutoff frequency to 15 kHz.)
-De-featable Analog FM Processing delay: 0.27 to 16.384 seconds, adjustable in one- sample increments at 64 kHz sample rate to allow the delays of the analog and digital paths in the HD Radio system to be matched at the receiver output. 
Minimum Processing Delay: Processing structure dependent. Typically 17 ms for normal latency Five band, 13 ms for low-latency Five-band, 3.7 ms for ultra-low-latency Five- band, and 17 or 22 ms for two band, depending on crossover structure chosen. MX presets have approximately 270 ms delay.