bastl instruments propust price : $59.00
propust diy kit user assembly required price : $44.00

propust is a compact tripple passive filter with with fixed cutoff frequencies for highpass and lowpass stages. it is a simple rc filter with 2 stages for hp and one stage for lp. there is a drop in signal loudness. no power connection is required. simple fixed filters can help you to clean up your final mix and make room for each sound, or they can be used for filtering noises and other signals when generating drum sounds, for instance. when the signal goes thru both hp and lp stages, it creates bp.

features:
tripple highpass 2-pole filters (cutoffs are cca 7khz, 3.5khz and 220hz)
tripple lowpass 1-pole filters (cutoffs are cca (1.5khz, 4.1khz and 880hz)
passive design > signal drop + no power connection

technical details:
2hp
15mm deep
passive design - no power needed

download the manual here.