The OPTIMOD 6300 is a high-quality, multipurpose stereo audio processor for digital radio (DAB+, HD Radio), digital television, netcasts, STL protection, satellite uplink protection, and digital mastering.
Background information: What to consider when it comes to Audio Processing for DAB+/Streaming
Thanks to versatile signal routing, the 6300 can also serve as a studio AGC with an all-digital signal path, and simultaneously as a talent headphone processor.
Because all processing is performed by high-speed mathematical calculations within digital signal processing (DSP) chips, the processing has cleanliness, quality, and stability over time and temperature that is unmatched by analog processors.
Absolute Control of Loudness and Peak Modulation
The OPTIMOD 6300 includes third-generation CBS Loudness Controllers™ for DTV applications. Loudness controllers work with the both Two-Band and Five-Band structures. The third-generation improvements reduce annoyance more than simple loudness control alone, doing so without audible gain pumping. Attack time is fast enough to prevent audible loudness overshoots, so the control is smooth and unobtrusive. Material processed by the CBS Loudness Controller has been shown to be well controlled when measured with a long-term loudness meter using the ITU-R BS.1770-2 standard. The 6300 also includes a “BS.1770 Safety Limiter” that follows the CBS Loudness Controller; use the BS.1770 if the BS.1770-2 meter reading must be constrained to a preset value.
The 6300 also implements “True Peak” Control by oversampling the peak limiter’s sidechain at 192 kHz. This allows the 6300 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 conversion from 48 kHz to 44.1 kHz is highly unlikely to cause sample peak clipping in the 44.1 kHz audio data.
The 6300 includes analog and dual AES3 digital inputs and outputs. The digital input and digital outputs have sample-rate converters and can operate at 32 kHz, 44.1 kHz, 48, 88.2, and 96 kHz sample rates. The pre-emphasis status and output levels are separately adjustable for the analog and digital outputs.
The outputs can be independently configured to emit the output of the AGC or the output of the multiband compressor/limiter, all configurable to use or bypass look-ahead limiting. So a 6300 can be configured to drive an STL with a peak-limited output from the AGC while also providing a fully processed digital radio/netcast feed and a low delay, multiband compressed talent headphone feed.
Adaptability through Multiple Audio Processing Structures
The 6300 features two processing structures: Five-band for a spectrally consistent sound with good loudness control, and Two-band for a transparent sound that preserves the frequency balance of the original program material while also effectively controlling subjective loudness. There are over 60 Factory Presets wich are our “factory recommended settings” for various program formats or types. There are multiple Factory Presets for both radio-oriented and video oriented programming.
Orban’s new PreCode™ technology manipulates several aspects of the audio to minimize artifacts caused by low bitrate codecs, ensuring consistent loudness and texture from one source to the next. There are several factory presets tuned specifically for low bitrate codecs.
The OPTIMOD 6300 Audio Processor can be remote-controlled by 5-12V pulses applied to eight programmable, optically isolated “general-purpose interface” (GPI) ports.
Moreover, because the 6300 supports presets that be recalled by remote control, it can be automatically synchronized to the presets on-air at a transmitter side Optimod when presets are dayparted. The 6300’s software can be upgraded by running Orban-supplied downloadable upgrade software on a PC.
An LCD and full-time LED meters make setup, adjustment and programming of the 6300 easy you can always see the metering while you are adjusting the processor. Navigation is by dedicated buttons, soft buttons (whose function is context-sensitive), and a large rotary knob. The LEDs show all metering functions of the processing structure (Two-Band or Five-Band) in use.
Push one of the dedicated buttons to “Recall” a preset, to “Modify” processing, or to access the system’s Setup controls.
Absolute Control of Peak Modulation
The 6300 precisely controls peak levels to prevent clipping or overmodulation in transmission media. The maximum level of the digital samples is controlled to better than 2%.
The 6300 implements “true peak” control by oversampling the peak limiter’s sidechain at 192 kHz. This allows the 6300 to prevent clipping in a playback device’s analog signal path by predicting and controlling the analog peak level following the playback device’s recon-struction 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.
While primarily oriented toward “flat” media, the 6300 can also provide pre-emphasis limiting for the two standard preemphasis curves of 50µs and 75µs. This allows it to protect pre-emphasized satellite uplinks and similar channels where protection limiting or light processing is required.
The 6300 includes analog and dual AES3 digital inputs and outputs. The digital input and digital outputs have sample-rate converters and can operate at 32 kHz, 44.1 kHz, 48, 88.2, and 96 kHz sample rates. The pre-emphasis status and output levels are separately adjustable for the analog and digital outputs. Note that the 6300 cannot provide simultaneous, independent audio processing for flat and pre-emphasized channels. Even though one output may be pre-emphasized while other is flat, the only difference between the outputs is that the “flat” output has de-emphasis applied to it after the processing while the pre-emphasized output does not.
OPTIMOD-DAB’s outputs can be independently configured to emit the output of the AGC or the output of the multiband compressor/limiter, all configurable to use or bypass look-ahead limiting.
THE 6300 controls the audio bandwidth as necessary to accommodate the transmitted sample frequency. OPTIMOD-DAB’s high frequency bandwidth can be switched instantly (typically in 1 kHz increments) between 10 kHz and 20 kHz. 20 kHz is used for highest-quality systems. 15 kHz meets the requirements of any system that uses 32 kHz sample frequency, while 10 kHz is appropriate for 24 kHz sample frequency.
The 6300’s dual-mono mode allows entirely separate mono programs to be processed, facilitating dual-language operation. In this mode, both processing channels operate using the same processing parameters (like release time); you cannot adjust the two channels to provide different processing textures.
Adaptability through Multiple Audio Processing Structures
A processing structure is a program that operates as a complete audio processing system. Only one processing structure can be on-air at a time. The 6300 realizes its processing structures as a series of high-speed mathematical computations made by Digital Signal Processing (DSP) chips.
The 6300 features two processing structures: Five-Band for a spectrally consistent sound with good loudness control, and Two-Band for a transparent sound that preserves the frequency balance of the original program material while also effectively controlling subjective loudness.
In the Five-Band structure, Orban’s PreCode™ technology manipulates several aspects of the audio to minimize artifacts caused by low bitrate codecs, ensuring consistent loudness and texture from one source to the next. PreCode includes special audio band detection algorithms that are energy and spectrum aware. This can improve codec performance on some codecs by reducing audio processing induced codec artifacts, even with program material that has been preprocessed by other processing than Optimod. There are several factory presets tuned specifically for low bitrate codecs.
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 Five-Band and the Two-Band structures can be switched via a mute-free crossfade.
OPTIMOD-DAB’s Two-Band structure includes a CBS Loudness Controller™ for DTV applications. The CBS algorithm has proven its effectiveness by processing millions of hours of on-air programming since the early 1980s. It smoothly limits subjectively perceived loudness to a broadcaster-set threshold, preventing audience irritation. The controller measures subjective loudness (as perceived by an average listener) and then closes a feedback loop to limit loudness to a preset level. It effectively controls loud commercials, which are the primary irritant in sound-for-picture applications. Third generation improvements reduce annoyance more than simple loudness control alone, doing so without audible gain pumping. New in version 2.0 software is the ability to adjust the attack time, trading off short-term loudness control against transient punch.
The subjective loudness meter, labeled Loudness Level in the 6300’s GUI, uses the CBS Technology Center algorithm developed by Jones and Torick. When used to drive a transmission channel using the Dolby Digital® codec, the Loudness Level meters (one for stereo processing or two for dual-mono processing) can be aligned to the Dialnorm metadata value in the Dolby Digital bitstream conveying the 6300’s output signal to the consumer’s receiver. When this is done, the loudness level at the receiver will be correct when the 6300’s processing is adjusted to make dialog peak at “0 dB” on the 6300’s Loudness Level meter. This processing fully complies with the loudness control requirements in ATSC A/85:2011 and EBU R 128.
The Loudness Level meter is also useful for mastering because it can help ensure consistent loudness from one track to the next on CD, DVD, or Blu-ray media. The CBS Loudness Controller is not needed with the Five-Band processing because the Five-Band processing’s spectral consistency creates consistent loudness as a desirable byproduct.
The 6300’s AGC rides gain over an adjustable range of up to 25dB, compressing dynamic range and compensating for both operator gain-riding errors and gain inconsistencies in automated systems. The AGC output is available to drive STLs, so the 6300 can be used as a studio AGC.
The 6300’s processing structures are all phase-linear to maximize audible transparency.
All compressors in the Two-Band and Five-Band structures have compression ratio and knee shape controls for each band’s compressor, making the 6300 perfect for applying subtle compression in mastering applications.
The 6300 can be remote-controlled by 5-12V pulses applied to eight programmable, optically isolated “general-purpose interface” (GPI) ports.
6300 PC Remote software is a graphical application that runs under Windows 2000 and XP, Vista,7 and 8. It communicates with a given 6300 via TCP/IP over modem, direct serial, and Ethernet connections. You can configure PC Remote to switch between many 6300s via a convenient organizer that supports giving any 6300 an alias and supports grouping multiple 6300s into folders. Clicking a 6300’s icon causes PC Remote to connect to that 6300 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 6300 features (including advanced controls not available from the 6300’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.).
The 6300 contains a versatile real-time clock, which allows automation of various events (including recalling presets) at pre-programmed times. To ensure accuracy, the clock can be synchronized to an Internet timeserver.
A Bypass Test Mode can be invoked locally, by remote control (from either the 6300’s GPI port or the 6300 PC Remote application), or by automation to permit broadcast system test and alignment or “proof of performance” tests.
The 6300 contains a built-in line-up tone generator, facilitating quick and accurate level setting in any system.
The 6300’s software can be upgraded by running Orban-supplied downloadable upgrade software on a PC. The upgrade can occur remotely through the 6300’s Ethernet port or serial port (connected to an external modem), or locally (by connecting a Windows® computer to the 6300’s serial port through the supplied null modem cable).
Specifications apply for measurements from analog left/right input to analog left/right output.
Frequency Response (Bypass Mode): Depending on settings, is flat or follows standard 50µs or 75µs preemphasis curve ±0.10 dB, 20 Hz-20 kHz. (At 32 kHz input sample rate, the passband is reduced to approximately 14.7 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 Multiband 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 20 kHz. <0.02% SMPTE IM Distortion.
Polarity (Two-Band and Bypass Modes): Absolute polarity maintained. Positive-going signal on input will result in positive-going signal on output.
Processing Resolution: Internal processing has 24 bit (fixed point) or higher resolution; uses four 150 MHz Motorola DSP56367 DSP chips. All equalizers and crossovers use double-precision arithmetic to achieve mastering-quality processing.
Internal Processing Sample Rate: 48 kHz. Although this rate is not currently fashionable, we believe that it is optimum, pro-audio marketing spin to the contrary. No bias-controlled listening tests (i.e., double-blind with matched levels) have demonstrated that humans can hear the difference between 48 kHz and higher sample rates. Meanwhile, the double-precision equalizers and crossover filters used throughout the 6300 produce at least 6 dB lower noise and nonlinear distortion than they would at 96 kHz.
Delay: The minimum available input/output delay is approximately 23 ms, as determined by the advanced “look-ahead” processing algorithms employed. This can be padded to exactly one frame of 24, 25, 29.97, or 30 frames/second video and can also be adjusted in 1 ms intervals up to 60 ms. The input/output delay to the Headphone Monitor output is approximately 5 ms. (This output has no peak limiting applied to it.)
Operating mode: Stereo or dual-mono. In dual-mono mode, both processing channels have the same subjective adjustments (as determined by the active preset) but are otherwise independent, making this mode appropriate for dual-language processing.
Analog Audio Input
Configuration: Stereo / Dual-Mono.
Impedance: >10kΩ load impedance, electronically balanced.
Nominal Input Level: Software adjustable from -4.0 to +13.0 dBu (VU).
Maximum Input Level: +27 dBu.
Connectors: Two XLR-type, female, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3 electronically balanced, floating and symmetrical.
A/D Conversion: 24 bit 128x oversampled delta sigma converter with linear-phase anti-aliasing filter.
Filtering: RFI filtered, with high-pass filter at 0.15 Hz (-3 dB).
Analog Audio Output
Configuration: Stereo / Dual-Mono.
Source Impedance: 50Ω, electronically balanced and floating.
Load Impedance: 600Ω or greater, balanced or unbalanced. Termination not required or recommended.
Output Level (100% peak modulation): Adjustable from -6 dBu to +24 dBu peak, into 600Ω or greater load, software-adjustable.
Signal-to-Noise: >= 90 dB unweighted (Bypass mode, de-emphasized, 20 Hz-15 kHz bandwidth, referenced to 100% modulation).
L/R Crosstalk: <= -70 dB, 20 Hz-15 kHz.
Distortion: <= 0.01% THD (Bypass mode, de-emphasized) 20 Hz-15 kHz bandwidth.
Connectors: Two XLR-type, male, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3 electronically balanced, floating and symmetrical.
D/A Conversion: 24 bit 128x oversampled.
Filtering: RFI filtered.
Digital Audio Input
Configuration: Stereo or Two-Channel (dual-mono) per AES3 standard, 24 bit resolution, software selection of stereo or dual-mono. Unit can detect Stereo or Two-Channel status bits and switch modes appropriately.
Sampling Rate: 32, 44.1, 48, 88.2, or 96 kHz, automatically selected.
Connector: XLR-type, female, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer balanced and floating, 110Ω impedance.
Input Reference Level: Variable within the range of -30 dBFS to -10 dBFS.
J.17 Deemphasis: Software-selectable.
Filtering: RFI filtered.
Digital Audio Output
Configuration: Stereo or Two-Channel per AES3 standard. Output configured in software as flat or pre-emphasized to the chosen processing preemphasis (50µs or 75µs), with or without J.17 preemphasis.
Sample Rate: Internal free running at 32, 44.1, 48, 88.1 or 96 kHz, selected in software. Can be synced at 32, 44.1, 48, 88.1 or 96 kHz to 1x wordclock or AES11id applied to the Sync input or to AES3 or AES11 signals applied to the AES3 digital input.. (Passband is limited to approximately 14.7 kHz when using 32 kHz output sample rate.)
Word Length: Software selected for 24, 20, 18, 16 or 14-bit resolution. First-order highpass noise-shaped dither can be optionally added, Dither level automatically adjusted appropriately for the word length.
Connector: XLR-type, male, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer balanced and floating, 110Ω impedance.
Output Level (100% peak modulation): -20.0 to 0.0 dBFS software controlled.
Filtering: RFI filtered.
Configuration: Can accept wordclock or AES11id (75Ω) sync, selectable in software.
Connector: Female BNC.
Termination: Unterminated. For wordclock, use an external 75Ω terminator if the 6300 is the last item in the chain. For AES11id, always use a 75Ω terminator.
Remote Computer Interface
Configuration: TCP/IP protocol via direct serial cable connect, modem, or Ethernet interface. Modem is not supplied.
Serial Port: 115 kbps RS-232 port dB-9 male, EMI-suppressed.
Ethernet Port: 100 Mbit / sec on RJ45 female connector.
Remote Control (GPI) Interface
Configuration: Eight (8) inputs, opto-isolated and floating.
Voltage: 6-15V AC or DC, momentary or continuous. 9VDC provided to facilitate use with contact closure.
Connector: DB-25 male, EMI-suppressed.
Control: User-programmable for any eight of user presets, factory presets, bypass, test tone, stereo or mono modes, analog input, digital input.
Filtering: RFI filtered.
Voltage: 100-264 VAC, 50-60 Hz, 40 VA.
Connector: IEC, EMI-suppressed. Detachable 3-wire power cord supplied.
Grounding: Circuit ground is independent of chassis ground, and can be isolated or connected with a rear panel switch.
Safety Standards: ETL listed to UL standards, CE marked.
Operating Temperature: 32º to 122º F / 0º to 50º C for all operating voltage ranges.
Humidity: 0-95% RH, non-condensing.
Dimensions (W x H x D): 19″ x 1.75 ” x 14.25″ / 48.3 cm x 4.4 cm x 36.2 cm. 1RU.
Humidity: 0-95% RH, non-condensing.
RFI / EMI: Tested according to Cenelec procedures. FCC Part 15 Class A device.
Shipping Weight & Dimensions: 18 lbs / 8.2 kg – 23″ x 23″ x 6″
Five Years, Parts and Service: Subject to the limitations set forth in Orban’s Standard Warranty Agreement.
Because engineering improvements are ongoing, specifications are subject to change without notice.