The 8400: Orban’s ‘Best-Ever’

Two main reasons audio processing is employed on FM radio stations are, of course, to prevent over-modulation and maintain a relatively consistent audio level for changing program content. The Optimod-FM 8000 did that job very satisfactorily.
Publish date:

A Major-Market Engineer Finds That the New Optimod Overcomes His Analog Prejudices
Product CapsuleThumbs Up:

Easy user interface for a very complicated device

Bright multicolored LCD screen

Comprehensive remote control including IP options

Excellent on-board AGC

Excellent "preliminary" manual

The cleanest and loudest Optimod ever

Thumbs Down:

None of the format presets delivered a truly dial-dominating but dynamic result

Hard to convince management to purchase now since my 8200 is only a few years old

Overall delay of 50 ms makes sidechain monitoring necessary

For information contact Orban in California at (510) 351-3500 or visit
Two main reasons audio processing is employed on FM radio stations are, of course, to prevent over-modulation and maintain a relatively consistent audio level for changing program content. The Optimod-FM 8000 did that job very satisfactorily.

But as the state of the art of processing audio has improved, the loudness bar has been raised across the dial in every market. You keep pace, or you get left behind by 2 or 3 dB. Maybe even more.

As long as PDs and engineers have continued to believe that being loud and clean is important, Bob Orban has continued to perfect the Optimod. With each version of this venerable box, stations gained more control in achieving their on-air sound objectives.

But getting loud and staying clean, especially in the all-digital world we now inhabit, has been an evolving and continuous challenge.

Convincing performance

Digital processors have the ability to "look ahead" at peak waveforms and precisely control them by crunching numbers in ways analog processors could never even attempt. But harnessing a digital engine to enhance sound for the analog process of human hearing has proven to be a rather complicated endeavor requiring a ton of R&D with trial-and-error listening.

There are still many audio processing aficionados who believe that a carefully tweaked analog system consisting of an Optimod-FM 8100 and various other before-and-after boxes produces a more consistent, friendly, yet competitively loud sound signature than any digital processor out there.

And there are many who believe that the Optimod-FM 8200 offers more than enough processing to stay competitive and that there isn’t enough margin for improvement left to justify buying the next level.

If you are either of those, as I used to be, the 8400 very likely will change your thinking. Especially if your competitor puts one on the air before you do.

Before describing the ability of the Optimod-FM 8400 to get out of the blocks and perform on the radio dial, the physical appearance and dashboard user interface deserve attention. The first impression conveys a kind of "Fisher-Price" look, with a two-tone gray case and royal blue control panel dotted with red, green and yellow buttons.

But this box is hardly just a high-tech toy. The 8400’s control interface sports a bright, multicolored LCD screen, with selected parameters highlighted and chosen by cursor and enter buttons. Navigation is smooth and effortless. A large blue shuttle-wheel knob is pushed to bring up and change menu selections and jogged left or right to change parameter magnitudes for less/more control.

The 10-year-old Optimod-FM 8200 emerged during the era of the 386 PC. Even the general manager can tell you that computer processing power has improved dramatically since then. With the state-of-the-art Motorola DSP56362 processor, the latest Optimod now has 5.5 times more processing horsepower to crunch numbers with ultra-precise resolution.

Control levels

Perhaps one of the secrets of the Optimod family’s historical success has been its ability to be consistent with all kinds of source material with any format, not letting the user get into trouble creating something awful, even with maxed-out adjustments.

Most of the truly dangerous parameters that might be adjusted beyond listen-ability were kept out of the user’s reach. The 8400 retains a natural two-band phase linear "purist" processing structure, as well as the more powerful five-band structure, with an architecture similar to that found in the 8200.

Competitive pressure from other processors that feature more control and alleged loudness potential has perhaps persuaded Orban to incorporate more access and adjustability. The 8400 offers three levels of parameter control:

    • "Basic Modify," which allows the user to control the newly added stereo enhancer, the equalizer and the dynamics functions of multi-band compression, limiting and clipping with a simple "less/more" control;

      • "Intermediate Modify," which offers additional control of the dynamics functions, similar to what was available with the 8200; and

        • "Advanced Modify," which offers control of several critical parameters never offered previously in any Optimod, including attack timing and thresholds, plus automatic clipping distortion controls. Orban strongly suggests this section is best left to experienced users familiar with on-air sound signature design.

        The collection of format presets offers 20 distinct flavors which cover most significant format types and typical processing signatures found in any crowded FM market.

        They include several variations for each of the major format categories, including classical, rock, oldies, country, urban and a "loud" family that all users should evaluate, considering they were conceived and perfected through a joint effort of Bob Orban and Greg Ogonowski.

        Orban suggests starting with a preset that matches your format and then perhaps doing some additional custom tweaking, first in the Basic Modify and then in the Intermediate Modify section as necessary to achieve the desired final sound signature.

        That’s good advice for most users. But we were interested in discovering if the 8400 could produce something truly unique and impressive beyond what its predecessor or any standard presets could deliver.

        We installed the 8400 on our mainstream top-40 station. It replaced an 8200 and version 3.0 firmware that was pedal-to-the-metal with a few flavoring boxes ahead of it.

        For those of us still caught in loudness wars, the prevailing consensus concerning the 8200 has been that it had to be adjusted perhaps too aggressively to compete fully or "dominate." It just tended to run out of gas on the steep slopes.

        But to be fair, the main competitors were barely any better and have had consistency problems of their own.

        On the air

        After spending only a short time with the 8400 on the bench, with raw studio audio driving a QEI 691 mod monitor hooked to a decent amp and speaker set, it was apparent this box was in a new class by itself.

        Rather than follow the step-by-step directions provided in the preliminary manual, we’ve always preferred to play with these kinds of devices intuitively at first, testing the limits of the major parameter controls. Then when we needed answers to specific concerns or questions, the manual was indeed quite helpful.

        We tried the "loud" preset options first, but concluded they were too busy, too fatiguing or just too over-processed for our tastes. So to achieve a cleaner, more open flavor, yet with sufficient punch and loudness demanded by the PD, we started with the instrumental preset and modified up from that.

        In general, low-end clipping is held soft to keep the bass honest, and release times are kept on the slow side to preserve dynamic feel and definition. Loudness is augmented with multi-band drive and carefully chosen clipping settings in Advanced Modify. Each highlighted parameter being modified also displays a helpful descriptive tag nearby to guide the user during adjustments.

        It took the better part of a week of small step changes from a base-line starting point and then daily evaluation to arrive at an adjustment set that engineers, jocks and the PD all agree is an impressive and significant improvement over what we had with the 8200.

        The most striking difference is in the perceived cleanliness of both the lows and highs, while maintaining dominant loudness. The one word the PD likes to use describing the result is improved "clarity."

        Certainly the look-ahead limiting capabilities and increased processing horsepower have much to do with that. Digital grunge is truly once and for all a thing of the past with this processor. And consistency from song to song holds up well, even from older, relatively unprocessed recordings to the current crop of many over-processed CDs that music companies are bound and determined to deliver to radio stations.

        On the level

        Although the manual suggests using an Optimod Studio Chassis ahead of the STL if the 8400 is placed at the transmitter, we found that no additional AGC controller was necessary with the unit at the studio ahead of the STL. Orban finally got the AGC nailed in this version of the Optimod, so don’t worry about adding a Compellor, Studio Chassis or some other leveler ahead of it.

        The 8400 will be remote-controllable via a Windows-based PC with serial or PCMCIA NIC interface with password protection. The next version of operating software, V 0.95, soon to be released, will include TCP/IP control. With a private IP address, you will be able to use the Internet to access and control it. New software updates will be downloadable directly from the Orban Web site.

        Because of the look-ahead limiting, overall delay through the 8400 is about 50 milliseconds. That compares with only 2.7 msec on the 8200, which was inaudible for jocks monitoring in real-time headphones.

        That old habit will not work at all with 50 msec, so a sidechain for headphone monitoring is definitely necessary, as cautioned in the manual. This also presents a problem for live remotes and traffic reports, so be prepared to set up real-time IFB and mix-minus circuits.

        Orban says the version 0.95 software will add the ability to switch the analog outputs to provide a low-delay, albeit-non peak-limited, monitor output.

        The retail price of the processor is $10,700.

        After living with this best-ever Optimod for three weeks on-air, the PD and staff have fallen in love with their new air-sound and will not give up the 8400. That’s the best endorsement we can articulate to management to justify approving capital funds for its purchase. We only hope the corporate bean counters will approve.