The OPTIMOD-AM 9300 Digital Audio Processor Orban's all-digital 9300 OPTIMOD-AM Audio Processor can help you achieve the highest possible audio quality in monophonic AM shortwave, medium wave and long wave broadcasts. 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 DSP56367 digital signal processing chips, the processing has cleanliness, quality, and stability over time and temperature that is unmatched by analog processors. OPTIMOD-AM 9300 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 6300 Multipurpose Digital audio Processor.) The 6300 can be set up so that it substitutes for the broadband AGC circuitry in OPTIMOD-AM, which is then defeated. Making the Most of the AM Channel 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. 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 preemphasis 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 preemphasis curve.