Just which station is responsible for creating the first production
room has probably been lost to history. No doubt it was conceived and
perhaps constructed following a maintenance catastrophe that
paralyzed the primary control room. A second studio, configured much
like the main studio, then became a standard design feature of radio
Because these second studios were set up as backup air studios, they
used essentially the same equipment and had similar recording,
playback and mixing philosophies. Eventually, the basic equipment
would include the common audio recorders and players of the day but
little else beyond microphones.
By the late '70s, production studios began to depart slightly from
the traditional duplicate studio model. One difference is the
inclusion of signal processing. No longer simply a duplication of the
air studio, today's production facility has almost as much in common
with a recording studio as with the broadcast booth.
Signal processing has come a long way in the past 30 years. My 1969
edition of Tremaine's Audio Cyclopedia has a section on equalizers
but makes little mention of other outboard devices, such as
compressors and artificial reverb or echo.
A discussion during an NAB2000 seminar is a case in point. The
moderator queried the audience about the technology they had used in
the past. Most recalled that it was the early '80s before almost any
outboard equipment, such as reverb, EQ, compressor/limiters or other
signal processing infiltrated their production rooms. At the time,
these devices were commonplace in the recording industry but not in
radio broadcast. They were often bulky, expensive and hardly the type
of equipment a bottom-line oriented station manager thought necessary.
By definition, an audio processor manipulates the waveform in some
manner. Whether by analog or digital means, characteristics such as
amplitude and frequency response can be shaped and modified to
achieve the desired sonic effect. Musical pitch and tempo can be
altered for a performance that is closer to perfection. Even
subtleties such as mic selection and the reverberant field are now
Why should we change the sound in the first place? There are two
answers to this question: problem solving and station identity. The
station with the best sound on the air has the best chance of
attracting an audience and keeping it. The station that chooses to
put better production on the air, broadcast better-sounding news
actualities and maintain a more consistent level of audio quality has
a step up on the competition.
When to process
At nearly all radio stations, much program content is delivered from
sources outside of the radio station in forms such as recorded music,
commercial or promotional announcements and network feeds. The
production of these elements is often carried out using the finest
mics and processors. The local producer, therefore, must have similar
tools available to avoid poor-sounding audio by comparison. A good
room environment and microphone combination are essential, but
additional help may be called for.
Voice processors have become common in air and production studios.
Their function is to enhance the voice by controlling dynamic range
and equalization. If an announcer tends to accent some words and drop
others, the internal compressor will compensate for these variations
in level. Excess vocal sibilance will benefit from the corrective EQ
or de-essing circuitry in a mic processor. With the right EQ setting,
a basic mic can sound better than it should. The right setup on the
compressor can help hide room noise, such as that from the computer.
Some processors include a means of linking units or controlling them
externally through sidechains. Some mic processors allow external
control of their compression function, which is especially handy in a
talk format: the host mic can be set up to automatically lower the
gain on the guest mics during a moment of controversy. (For more on
talk-show technology, see Let's Talk, July 2000 BE Radio, pg. 28.)
Many all-in-one mic processors go beyond multi-band equalization and
dynamic range control to provide phantom power, phase reverse,
dual-channel operation and other features.
One of the goals in the production studio is to make sure the final
project attracts attention as intended. What good is a commercial no
one notices? Enter "special effects" - sounds so unnatural they
immediately attract the ear. Experimentation (also known as messing
around) resulted in all manner of new sounds, from electric lasers,
to Santa's elves and Darth Vader. The first generation flangers,
chorus, reverbs and delays were often packaged as separate units.
Some were originally designed for electric guitars but pressed into
service in the production studio. Today, these effects processors are
commonly combined into one integrated unit and include
compressor/limiter functions, reverb, delay and EQ. Most ship with
preset off-the-rack sounds, but they allow the user to create and
store custom effects. Price points for these devices are as
wide-ranging as the number and sophistication of the sounds available.
One of the oldest effects processors is the equalizer. Its original
use was to match the frequency response of telephone lines or
loudspeaker system to "equal" or flat response for more accurate
A graphic equalizer is a collection of tuned filters that can boost
or cut a particular range of frequencies. Human hearing has about a
10-octave range. Equalizers are usually described generically in
terms of the number of frequency bands the unit has or how the
sections are divided. A 1/3-octave EQ, for example, divides each
octave into three parts.
In production, an equalizer can be used not only for special effects
but also as a problem-solver. For instance, your field reporter has
just called in a breaking story, but the feed has a mysterious hum.
Using a graphic and your ears, you can determine which band of
frequencies contains the hum. By reducing the level of the offending
frequencies, you bring down the hum, making the reporter more easily
understood. However, because the graphic works in fixed bands of
frequencies, a more precise EQ may be called for.
The parametric EQ divides the spectrum into three or more frequency
bands. The user first determines a general range for the individual
band and adjusts for a center frequency. Second, using the bandwidth
control, or Q, the user adjusts for the desired range of frequencies
above and below the center. Boost or cut is applied as necessary. The
strongest of these equalizers is called a notch filter and can be set
to control a very narrow bandwidth.
The least glamorous production tool is the compressor/limiter.
Compressors reduce the overall dynamic range of a source to prevent
overloads and improve intelligibility or musicality. The operator
sets the compression ratio. This means a signal of a given level may
increase by several decibels, but the compressor will only allow a
slight increase at its output. Above a certain threshold, the signal
is completely limited; there is no output increase. The operator has
additional controls for attack and decay, which are useful in musical
situations where a misadjustment would cause distortion.
Compressor/limiters are commonly used on individual voices or
instruments in a mix, or as overall program limiting inline ahead of
a recording device or transmitter.
When a commercial spot ran a little long in the analog production
studio, you either did it over or fudged the label and hoped no one
caught on. If a variable-speed tape recorder was available, you could
try to crank up the speed a little and hope not too much of the
dreaded chipmunk effect resulted. (A producer with access to a pitch
shifter could pull the pitch back down for the final dub, but before
digital equipment was common, quality pitch shifters were very
Computer-based hard-disk editing systems have revolutionized radio
production. They can help fit 63 seconds of production into a space
of 59 seconds. Software programs emulate nearly everything in the
previous generation production studio, from multitrack tape recorders
to razor blades.
The leading software programs for disk-based audio recording
typically ship with basic effects packages, including
time-compression tools for the above problem. Add-on options, called
plug-ins, provide additional signal-processing capabilities. Plug-ins
can be provided from the original editor manufacturer or from
third-party manufacturers. Many digital music software - on both
Windows and Mac platforms - accept these after-market applications,
which offer the same functional flexibility that traditional hardware
Many plug-ins emulate effects available only in hardware packages
that cost many times the cost of the software. The current generation
of plug-ins takes processing to a higher level, creating processors
without parallel in the analog or hardware world.
Third-party plug-ins can be written for use with several programs.
This is done by using an open format source, such as Microsoft's
Direct-X for PCs or Steinberg's VST for PC or Mac. There are many
other formats as well, some are not as common and may not offer as
many third-party DAW choices. An editing program's ability to support
plug-ins can provide additional flexibility for the future.
A number of software suppliers offer processors designed to remove
hiss, background noises such as traffic, HVAC, or unwanted artifacts
from the recording process. These processors typically work by
sampling and then phase-reversing a portion of the offending sound.
On the other side of that coin, some plug-in programs add noise back
in to recreate the characteristics of analog tape recording or vinyl
(33-, 45- or even 78 rpm) or to mimic the natural reverb of a
particular concert hall or studio.
Analog, digital and software-based processors are essential in the
well-equipped production studio. Of course, it takes a creative
producer to bring out the best in your station. In some areas, talent
like this is in short supply.