"Exi" Processors debut powerful new features for AM & FM
24 March 2005, Cleveland, OH USA
Omnia Audio announces a new line of audio processors for radio stations upgrading to HD Radio™ broadcasting: Omnia-6 EXi for FM, and Omnia-5 EXi for AM and FM broadcasters. The new EXi processors enhance and simplify the HD Radio audio chain and add essential new tools for HD Radio broadcasts, while simultaneously increasing the clarity and listenability of conventional AM and FM broadcasts: an onboard Diversity Delay method which simplifies and protects the broadcast signal of HD Radio for AM and FM, and an advanced new clipper design engineered to help eliminate Intermodulation Distortion (IMD).
Omnia President Frank Foti explains that “As more and more AM and FM stations ready for HD Radio, there’s growing concern among engineers about the technical complexity and reliability of the system. The biggest issue centers around the insertion of the required ‘diversity time delay’ — the process that synchronizes the analog and HD Radio signals in the receiver.”
Presently, the HD Radio system configuration inserts this “diversity delay” for the analog signal inside the HD Radio exciter. Says Foti, “This system design has enormous potential for failure. Interrupt the HD Exciter and the analog signal is off-the-air too!” To combat this, engineers have been forced to develop cumbersome, equipment-laden bypass methods. The audio routing method itself is complex and confusing as well.
The new Omnia-6 and Omnia-5 EXi audio processors combat this confusion with a new Omnia Diversity Delay feature, incorporating Diversity Delay into the audio processor and moving it out of the HD Radio exciter. “Omnia Diversity Delay improves system reliability because it easily isolates the HD Radio system from the conventional path,” explains Foti. “This also allows broadcasters to choose their own method of connectivity to the exciter. And,” says Foti, “the time delay allows us to devote more processing muscle to the conventional signal, so the sonic quality of the audio is even further improved."
The “processing muscle” Foti refers to comes partly in the form of the new LoIMD Clipper featured in all Omnia EXi –series processors. Making use of intelligent processing algorithms, the LoIMD clipper greatly reduces the inter-modulation distortion (IMD) that’s created when using moderate to aggressive clipping to create competitive loudness.
“You get IMD when upper midrange and presence frequencies are pushed into clipping by large, lower frequencies,” Foti explains. “It manifests as a rattling, warbling audio texture that can really destroy the listening experience."
“Even though competitive loudness is important, savvy broadcasters have realized that if you process for loudness at all costs, one of those costs might be your listeners,” Foti relates. “But our new LoIMD Clipper lets you have your cake and eat it, too! You can have truly amazing competitive loudness that will blow away your competition and still retain amazing detail and audio clarity.”
“Bottom line: you can crank it to ‘11’ and still sound fantastic!”
Omnia’s LoIMD Clipper works through the use of “intelligent” algorithms that actively adapt to signal content and density, producing sustained audio signals that don’t inter-modulate among other spectra. This complex balancing act allows the clipper to retain power and impact, yet reduce or eliminate IMD from moderate to aggressive levels of clipping. The overall effect is retained loudness and punch, along with the clarity and detail that listeners demand.
Three Omnia EXi –series processors are available:
- Omnia-6 EXi HD+FM has a unique parallel processing structure that routes audio from the mixer section to separate output stages for conventional FM and DAB. The FM section receives distortion-controlled final limiting with pre-emphasis, and an upper-frequency response of 15 kHz. The HD Radio / DAB section has a multi-band Look-Ahead final limiter with user-selectable frequency response all the way up to the full audio bandwidth of 20 kHz. Omnia-6 EXi features 96 kHz, 24-bit resolution, 6 bands of limiting, 5 AGC bands, and wideband AGC.
- Omnia-5 EXi HD+FM features the same parallel processing paths as its big brother, with two bands of AGC, wideband AGC, and a five-band limiter. Like the Omnia-6 EXi, its FM section features distortion-controlled final limiting with pre-emphasis and an upper-frequency response of 15 kHz; HD Radio / DAB section features Omnia’s famous program-adaptive Look-Ahead limiter; frequency response is user-selectable up to 20 kHz.
- Omnia-5 EXi HD+AM is the world’s only processor for conventional AM / MW and HD Radio / DRM broadcasts. Its dual processing structure routes audio from the multiband mixer section to separate, simultaneous output stages for analog and digital transmission. The HD Radio / DRM section contains Omnia’s program-adaptive Look-Ahead limiter, adjustable low-pass filtering and high-shelf EQ for clean, dynamic AM audio. Conventional AM is processed with an AM-optimized, distortion-cancelled final limiter with unique feedback/feed forward design for larger, warmer bass and open, natural highs.
Omnia EXi processors will be unveiled at the 2005 NAB Convention in Las Vegas; owners of existing Omnia-6, Omnia-5 and Omnia-4.5 processors can purchase an upgrade to add full EXi capabilities to their processors. To hear the new Omnia EXi processors, visit Telos Systems / Omnia Audio at Booth N2816 in the Las Vegas Convention Center April 18-21.
Omnia, a Telos company, is world-renowned for its digital audio signal processing expertise. Omnia audio processors for FM, AM, TV, HD Radio & DAB, Internet, and audio production are setting new standards for professional audio quality.