Orban's all-digital 9400 OPTIMOD-AM Audio Processor can help you achieve the highest possible quality in AM shortwave, medium wave and long wave broadcast sound. OPTIMOD-AM delivers louder, cleaner, brighter, FM-like audio with an open, fatigue-free quality that attracts listeners and holds them. Because all processing is performed by high-speed mathematical calculations within Motorola DSP56362 digital signal processing chips, the processing has cleanliness, quality, and stability over time and temperature that is unmatched by analog processors. The 9400 supports iBiquity’s HD AM® in-band on-channel digital radio system. The digital radio processing can also be used for simulcast netcasts or DRM digital broad- casts. In this manual, the processing for these applications will be referred to as “HD AM” processing, even though HD AM is only one application. OPTIMOD-AM 9400 is descended from the industry-standard 9100 and 9200 OPTIMOD-AM audio processors. Thousands of these processors are on the air all over the world. They have proven that the “OPTIMOD sound” attracts and keeps an audience even in the most competitive commercial environment. Because OPTIMOD-AM incorporates several audio processing innovations exclusive to Orban products, you should not assume that it can be operated in the same way as less sophisticated processors. If you do, you may get disappointing results. Take a little time now to familiarize yourself with OPTIMOD-AM. A small investment of your time now will yield large dividends in audio quality. OPTIMOD-AM was designed to deliver a high-quality FM-like sound to the listener's ear by pre-processing for the limitations of the average car or table radio (while avoiding audible side effects and compromises in loudness or coverage). Because such processing can make audible many defects ordinarily lost in the usual sea of AM mud, it is very important that the source audio be as clean as possible. Orban's publication Maintaining Audio Quality in the Broadcast Facility (available in .pdf form from ftp.orban.com) contains valuable information and specific suggestions for improving the quality of your audio. The rest of Section 1 explains how OPTIMOD-AM fits into the AM broadcast facility. Section 2 explains how to install it and set it up. Section 3 tells how to operate OPTIMOD-AM. Sections 4 through 6 provide reference information. For best results, feed OPTIMOD-AM unprocessed audio. No other audio processing is necessary or desirable. If you wish to place level protection prior to your studio / transmitter link (STL), use an Orban studio level control system expressly designed for this purpose. (At the time of this writing, this is the Orban 8200ST OPTIMOD-Studio Compressor/limiter / HF Limiter / Clipper.) The 8200ST can be adjusted so that it substitutes for the broad- band AGC circuitry in OPTIMOD-AM, which is then defeated. Making the Most of the AM Channel The 9400 is suitable for long wave, medium wave, and shortwave (HF) broadcasts. OPTIMOD-AM rides gain over an adjustable range of up to 25dB, compressing dynamic range and compensating for operator gain-riding errors and for gain inconsistencies in automated systems. OPTIMOD-AM increases the density and loudness of the program material by multiband limiting and multiband distortion-canceling clipping, improving the consistency of the station's sound and increasing loudness and definition without producing audible side effects. OPTIMOD-AM precisely controls peak levels to prevent overmodulation. Asymmetry in the analog processing channel is adjustable from 100% to 150% positive peak modulation. OPTIMOD-AM compensates for the high- and low-frequency rolloffs of typical AM receivers with a fully adjustable program equalizer providing up to 20dB of high-frequency boost (at 5 kHz) without producing the side effects en- countered in conventional processors. This equalizer can thus produce extreme pre-emphasis that is appropriate for very narrow-band radios. OPTIMOD-AM's fully parametric low- and mid-frequency equalizers allow you to tailor your air sound to your precise requirements and desires. OPTIMOD-AM also fully supports the NRSC standard pre-emphasis curve. OPTIMOD-AM is a stereo processor that fully protects CQUAM® transmissions, conservatively complying with Motorola’s processing requirements that negative peak modulation on the left and right channels be limited to –75% modulation. OPTIMOD-AM supports the iBiquity HD Radio® system. Except for common stereo enhancement and AGC, the HD AM processor is an independent processing chain with its own set of user-adjustable parameters, maintaining 15 kHz audio bandwidth (per iBiquity’s specifications) regardless of the bandwidth setting of the processing intended for the analog channel. To ensure source-to-source consistency, the digital radio processing includes full five-band compression/limiting that is independent of the five-band compression/limiting in the analog processing chain. This output can also be used for netcasts. Orban’s PreCodeTM 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 HD factory presets tuned specifically for low bitrate codecs. These presets have “LBR” in their names. Controllable and Adjustable The 9400 comes with a wide variety of factory presets to accommodate almost any user requirement. The user can readily modify these presets. Modified presets can be stored and recalled on command. Advanced Control (accessible from the PC Remote application) facilitates detailed sound design using the same controls that were available to the factory programmers. An LCD and full-time LED meters make setup, adjustment and programming of OPTIMOD-AM easy — you can always see the metering while you’re 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. OPTIMOD-AM contains a versatile real-time clock, which allows automation of various events (including recalling presets) at pre-programmed times. A Bypass Test Mode can be invoked locally, by remote control (from either the 9400’s GPI port or the 9400 PC Remote application), or by automation to permit broadcast system test and alignment or “proof of performance” tests. OPTIMOD-AM contains a built-in line-up tone generator, facilitating quick and accurate level setting in any system. OPTIMOD-AM's software can be upgraded by running Orban-supplied downloadable upgrade software on a PC. The upgrade can occur remotely through the 9400’s Ethernet port or serial port (connected to an external modem), or locally (by connecting a Windows® computer to the 9400’s serial port through the supplied null modem cable). The 9400 can be remote-controlled by 5-12V pulses applied to eight programmable, optically isolated “general-purpose interface” (GPI) ports. 9400 PC Remote software runs under Windows 2000 and XP. It communicates with a given 9400 via TCP/IP over modem, direct serial, and Ethernet connections. You can configure PC Remote to switch between many 9400s via a convenient organizer that supports giving any 9400 an alias and grouping multiple 9400s into folders. Clicking a 9400’s icon causes PC Remote to connect to that 9400 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 9400 features (including advanced controls not available from the 9400’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.).