Introduction
®
120A User Manual
i
120A
Congratulations on your purchase of the dbx® Professional Products 120A Subharmonic
Synthesizer with Modeled Waveform Synthesis™. The 120A has been specifically optimized to
enhance Bass audio material for use in a variety of professional applications, including night-
club and dance DJ mixing, theatre and film sound, music recording, live music performance and
broadcasting.
The 120A’s two separate bands of subharmonic synthesis provide the best combination of
smoothness and control, and the independent low frequency boost circuit is designed to get the
most out of high-performance low frequency speaker systems. Flexible system interfacing is
achieved by providing main outputs which can be full range (including synthesis) or high-fre-
quency ONLY, along with a separate subwoofer output with its own level control.
This manual will be your guide to understanding the full functionality of the powerful 120A.
After you have become familiar with the unit, we encourage you to experiment and find cre-
ative ways that the 120A can help you optimize your specific application.
The 120A’s patented modeled Waveform Synthesis™ process builds a synthesized waveform
using the wave shapes of the original bass material, producing a new Waveform Modeled™ bass
note, exactly one octave below the bass in the original audio signal path. Unlike other attempts
at bass synthesis, the dbx Professional Products 120A process produces smooth, musical low
frequencies that do not interfere with mid and high-band information even when the maximum
synthesis and boost are applied. The result is a low-end punch that people really feel, even at
system levels that won’t destroy sound equipment or damage hearing. The 120A offers the fol-
lowing features:
• Patented Modeled Waveform Synthesis™ Circuitry insures that mid and
high frequencies are not affected
• Individual Controls for Two Separate ranges of Subharmonic Frequencies,
plus Master Synthesis Level Control
• Separate Low Frequency Boost Circuit
• Separate Subwoofer Output
• 1/4” Balanced Inputs and 1/4” Impedance-Balanced Outputs
• RCA Inputs
• LF Synthesis LED Indicators
• Selectable Crossover with 80Hz and 120Hz crossover points
INTRODUCTION