An LCD and full-time LED meters make setup, adjustment and programming of OPTIMOD-FM 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 LEDs show all metering functions of the processing structure (Two-Band or Five-Band) in use.
Absolute Control of Peak Modulation
The 5700 provides universal transmitter protection and audio processing for FM broadcast. It can be configured to interface ideally with any commonly found transmission system in the world, analog or digital.
The 5700 provides pre-emphasis limiting for the internationally used pre-emphasis curves of 50µs and 75µs.
The 5700 achieves extremely tight peak control at all its outputs—analog, AES3 (for both the analog FM and HD channels), and composite baseband.
The stereo encoder has two outputs with independent level controls, each capable of driving 75Ω in parallel with 47,000pF, (100ft / 30m of coaxial cable).
By integrating the stereo encoder with the audio processing, the 5700 eliminates the overshoot problems that waste valuable modulation in traditional external encoders.
The 5700 prevents aliasing distortion in subsequent stereo encoders or trans- mission links by providing bandwidth limiting and overshoot compensated 15 kHz low-pass filters ahead of the 5700’s audio outputs and stereo encoder.
The 5700 has an internal, DSP-based stereo encoder (with a patented “half-cosine interpolation” composite limiter operating at 512 kHz sample rate) to generate the pilot tone stereo baseband signal and control its peak level. The composite limiter is a unique, “you can only do this in DSP” process that beats composite clippers by preserving stereo imaging while fully protecting the stereo pilot tone, RDS/RBDS, and subcarriers.
The stereo encoder’s stereo sub-channel modulator can operate in normal double sideband mode and in an experimental compatible single sideband mode that is offered to enable users to compare and assess the two modes. See SSB Stereo Encoder Operation on page 3-10.
The Digital Radio processing chain offers an ITU-R BS.1770-3 Loudness Meter and Safety Limiter for use in countries that enforce a BS.1770 loudness limit on digital radio broadcasts. The 5700/HD implements “true peak” control in its HD processing chain by oversampling the HD peak limiter’s sidechain at 256 kHz. This allows the 5700 to prevent clipping in a playback device’s analog signal path by predicting and controlling the analog peak level following 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. For example, sample rate con- version from 48 kHz to 44.1 kHz is highly unlikely to cause sample peak clipping in the 44.1 kHz audio data.
Adaptability through Multiple Audio Processing Structures
A processing structure is a program that operates as a complete audio processing system. The 5700 realizes its processing structures as a series of high- speed mathematical computations made by Digital Signal Processing (DSP) chips.
The 5700 features four processing structures: Five-Band (or “Multiband”) for a consistent, “processed” sound with 17 ms delay (typical), free from undesirable side effects, Low-Latency Five-Band (12 ms delay), Ultra-Low-Latency Five- Band (3.7 ms delay), and Two-Band (17 or 22 ms delay) for a transparent sound that preserves the frequency balance of the original program material. A special Two-Band preset creates a no-compromise “Protect” function that is functionally similar to the “Protect” structures in earlier Orban digital processors.
The 5700 can increase the density and loudness of the program material by multiband compression, limiting, and clipping—improving the consistency of the station’s sound and increasing loudness and definition remarkably, without producing unpleasant side effects.
The 5700 rides gain over an adjustable range of up to 25 dB, compressing dynamic range and compensating for both operator gain-riding errors and gain in- consistencies in automated systems.
The 5700’s Two-Band processing structures can be made phase-linear to maximize audible transparency.
Controllable
The 5700 can be remote-controlled by 5-12V pulses applied to eight programmable, optically-isolated “general-purpose interface” (GPI) ports available at the REMOTE INTERFACE connector on the rear panel.
5700 PC Remote software is a graphical application that runs under Windows 2000/XP/Vista/7/8/8.1. It communicates with a given 5700 via TCP/IP over modem, direct serial, and Ethernet connections. You can configure PC Remote to switch between many 5700s via a convenient organizer that supports giving any 5700 an alias and grouping multiple 5700s into folders. Clicking a 5700’s icon causes PC Remote to connect to that 5700 through an Ethernet network, or initiates a Windows Dial-Up or Direct Cable Connection if appropriate. The PC Remote software allows the user to access all 5700 features (including advanced controls not available from the 5700’s front panel), and allows the user to archive and restore presets, automation lists, and system setups (containing I/O levels, digital word lengths, GPI functional assignments, etc.).
SNMP support allows you to control and monitor the 5700 over your network by using the SNMP protocol and compatible software.
The 5700 includes a Telnet client that allows presets to be recalled via batch files using the free PuTTY and Plink applications. The commands are simple ASCII strings, facilitating interface to automation systems that can emit such strings through an Ethernet or RS232 serial connection.
OPTIMOD-FM contains a versatile real-time clock, which allows automation of various events (including recalling presets) at pre-programmed times. The clock can be set automatically from an Internet timeserver.
A Bypass Test Mode can be invoked locally, by remote control (from either the 5700’s GPI port or the 5700 PC Remote application), or by automation to permit broadcast system test and alignment or “proof of performance” tests.
OPTIMOD-FM contains a built-in line-up tone generator, facilitating quick and accurate level setting in any system.
OPTIMOD-FM's software can be upgraded by running Orban-supplied downloadable upgrade software on a PC. The upgrade can occur remotely through the 5700’s Ethernet port or serial port (connected to an external modem), or locally (by connecting a Windows® computer to the 5700’s serial port through the supplied null modem cable).
Silence alarm and digital audio fault tally outputs are available.
Upgradeable to 8600S
Via a purchased upgrade kit, the 5700 can be upgraded to full 8600S functionality via a network connection without removing the unit from the rack. This upgrade adds Orban’s exclusive MX limiter technology, which uses a built-in psychoacoustic model and other advanced signal processing techniques to add about 2.5 dB more high frequency power handling capability, lower distortion, and greater transient impact. The upgrade includes the full-featured RBS/RBDS generator as well. The generator supports dynamic PS. It can be controlled via 8600S presets and an ASCII terminal server that can be connected to automation to support displaying title and artist.
