12
551E
552E
/
Broadcast Systems
While analog equalizers do not enjoy the status of the latest multiband digital audio processors,
there is not a program director in the world who does not want a good equalizer somewhere in the
audio processing chain. The equalizing finesse possible with the Symetrix 551E/552E can provide
the final touch in producing a signature sound which trounces the competition.
On previous pages you learned how a parametric equalizer, especially the 551E/552E, runs circles
around a graphic EQ because of the precise adjustments possible. The important question
remaining is, “Where should I install the 551E/552E?”
Install the 551E/552E before the final limiter (see Diagram 11). If wired in the audio chain after the
final limiter, the frequencies you boost will cause over-modulation of the transmitter. If the 551E/
552E connects directly to the output of the console, sloppy board operation and unusually loud
peaks may combine to overload the equalizer’s input, in spite of its +22 dBu headroom. Ideally an
AGC, like the Symetrix 422 AGC-Leveler, should be installed between the console output and the
551E/552E’s input.
This combination provides protection for the 551E/552E’s input stage and delivers a leveled signal
to the final limiter. The station benefits from a consistent, finely equalized signature sound which
does not change with the program material, or each on-air shift change.
FINAL LIMITER
551E PARAMETRIC EQ
551E PARAMETRIC EQ
STEREO AGC/LEVELER
422
Diagram 11 - Recommended audio processing chain for broadcast systems. (Alternately, you could
substitute one 552E for the two 551E’s in this setup.)
