dbx DriveRack PA2 - Manual (Page 39)

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Subharmonic Synthesis (SUB)
dbx’s subharmonic synthesis (or sub-synth) processing has been specifically optimized to enhance the low frequencies in
audio material and was designed for use in a variety of professional audio applications, including nightclub and dance DJ
mixing, theatre and film sound, music recording, live music performance, and broadcasting. Using traditional EQ to enhance this
extremely low frequency region can increase noise potential and stage rumble (low-frequency feedback) in live PA systems.
Another problem is that the audio source may not have sufficient low end in this region to boost or the mic used to capture the
sound may not capture these extremely low frequencies. Subharmonic synthesis creates synthesized low frequencies based
on some of the higher frequencies in the audio program and gives you noise free low-end enhancement. The subharmonic
module’s two separate bands of subharmonic synthesis provide additional control for creating a deep, smooth low-end
response.
The level meters available in the Subharmonic Synth menu show
overall effect level, 35-56 Hz effect level, and 24-36 Hz effect level.
Use these meters while adjusting the subharmonic synthesizer’s
parameters to see how much of the effect you are adding to the
mix.
•
-60
LEVEL
36-56
24-36
-40 -24 -12 -6 0
Subharmonic Synthesis Level Meters
Subharmonic Synthesis Parameters
The Subharmonic Synth menu can be accessed by pressing the
SUB button. Turn the DATA wheel to scroll through the list of
parameters. Press the DATA wheel to edit a selection.
• SUBHARMONIC [ON, OFF]
This parameter turns the subharmonic synth module on and off.
• SUBHARMONICS [0% - 100%]
This parameter sets the overall level of the sub-synth effect.
• 36-56 HZ LEVEL [0% - 100%]
This parameter adjusts how much of the sub-synth effect is added between the 36 Hz to 56 Hz region. If the sound
becomes too “woofy” or “growly”, try turning this parameter down. You may find that a certain setting produces fine results in
one room, but produces too much “boominess” in another. If this occurs, adjust the parameter as needed.
• 24-36 HZ LEVEL [0% - 100%]
This parameter adjusts how much of the sub-synth effect is added between the 24 Hz to 36 Hz region. If your woofers are
bottoming out (making a ticking or popping sound), turn this parameter down. Enhance this frequency region less than the
36-56 Hz region (as shown in the above level meter screenshot) for more natural bass roll-off. Experimentation will pay off
with smooth, full, deeply extended bass.
importaNt! The subharmonic synthesis process produces extremely low-frequency audio signals that some
speakers may not be designed to reproduce. Attempting to achieve enhanced bottom end with these systems may not be
possible and may result in over-stressing or even damaging your loudspeakers. It is generally not a good idea to use this
feature without a subwoofer. In any case, please refer to your subwoofer speakers’ frequency response specification, and
avoid forcing them to reproduce low frequencies that they are not designed to reproduce.