500 Series Subharmonic Synthesizer, with 2 Subharmonic Frequency Bands and LED Metering

-Generates low frequency content one octave lower than the source audio
-Won't cloud your mids or highs, even at extreme settings
-Simple, intuitive design is easy to dial in
-Perfect for adding power to kick drums, or body to synthesizers
-Level indicator LEDs help prevent clipping

http://dbxpro.com/en-US/products/510