For over 30 years, Optimod-AM has dominated the sound of major market AM radio. The Orban Processors OPTIMOD-AM 9400 distills all of Orban’s experience into the best Optimod-AM ever! 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. 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.
The 9400 supports iBiquity’s HD AM® in-band on-channel digital radio system. The digital radio processing can also be used for simulcast netcast, DAB+, DRM or DRM+ digital broadcasts. Regardless of whether you have a major-market station or just want your station to sound like one, Optimod-AM 9400 is right for you.
Making the Most of the AM Channel
The Orban Processors OPTIMOD-AM 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 over-modulation. Asymmetry in the analog processing channel is adjustable from 100% to 150% positive peak modulation.
OPTIMOD-AM supports the iBiquity HD Radio® system, DAB+, DRM and DRM+ digital broadcast. 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
Optimal Control of Peak Modulation Levels
The analog AM audio processing circuitry in OPTIMOD-AM produces a waveform that is precisely peak-controlled to prevent over-modulation, and is low-pass filtered to protect adjacent channels and to conform to government regulations.
The Orban Processors OPTIMOD-AM 9400 controls the transmitted bandwidth of the analog channel to meet government regulations, regardless of program material or equalization. The high frequency bandwidth of the analog processing channel can be switched instantly in 500Hz increments between 4.5 kHz and 9.5 kHz (NRSC). The lower cutoff frequencies meet the output power spectral density requirements of ITU-R 328-5 without further low-pass filtering at the transmitter, while the 9.5 kHz filter meets the requirements of the NRSC-1 standard (North America). The 5.0 kHz filter makes the analog AM bandwidth compatible with HD AM transmission. The low-pass filters have parametric cutoff shapes, allowing you to trade off filter ringing against frequency response flatness.