Carl Martin Contour Boost Effects Pedal Low High Pass Filter [Contour] - $215.00 : GuitarBassPro!, Bass Guitars Amplifiers Pro Audio and accessories
NPD - Broughton Low + High Pass Filter. Does a great job of cleaning up muddy low end and hissy high end frequencies I don't want. Just the creamy middle! : r/BassGuitar
Broughton HPF High Pass Filter 2017 Black | Reverb
Other/unknown BROUGHTON Low + High Pass Filter - Pedal on ModularGrid
Is there a "high pass filter" and or "low pass filter" pedal (not reqular EQ)? | The Gear Page
Broughton High Pass Filter Pedal | Reverb
Review - Broughton Audio: Josh Wah, Low+High Pass Filter, and Apex Compressor - Bass Musician Magazine, The Face of Bass