Custom Order. In Stock with warranty. Maybe 20"or 25 Hz? If you need one, you can get an aftermarket equalizer with an onboard subsonic filter, like an AudioControl EQL. Actually, the only Pre-Amp of those mentioned that does have a switchable Subsonic filter is the Project Phono S box- Beyond that, I'm at a loss for what to suggest. Ported yes you'd probably use one but sealed should be fine. Pin It. What I experience however, with the subsonic filter setting is a greater sense of power from my amp, more PRAT, an enhanced mid-range, greater bass articulation, greater decay, greater 3 dimensionality, lower noise floor, and a more liquid, musical presentation with a noticeable increase of detail and clarity. Generally a subsonic filter isn't needed with a sealed enclosure. Set it to about 20 Hz. Dec 18, 2000 Harrison Labs manufactures high quality electronic products. Mar 16, 2009 #2. greenboy. Eduardo, A subsonic filter becomes necessary when a subwoofer and enclosure, usually the ported kind, resonate and play certain low frequencies much louder than the rest, wasting energy trying to play notes no one can hear. PFM Subsonic Filter; Illuminated Controls; Illuminated Logo; Parametric Bass Equalization; Balanced RCA Inputs; PWM Power Supply; Continuously Variable Bass Output Control; Output Level: up to 13.5 Volt; Frequency Response: 10Hz - 25KHz; THD: 0.0015%; S/N Ratio: <133dB In terms of assembling a sonically good filter, use a quality insualted wire for the ground wire, and make it no longer than necessary to bridge the gap between the two RCA plugs. They will pass everything above 20hz, and can be place between the Phono Pre-Amp and the Amp. Nestle the cap in between the RCA jacks, and using the tubing to insulate if necessary, use the caps own leads to connect to the hot pins. Tweet. The RMC OPT-01 is a 6-channel subsonic filter module that installs in the Roland GR-55 to eliminate the subsonic over-sensitivity in that unit. • RCA Noise Filter • Close to perfect response of +/- .03 dB from 20 Hz - 20kHz • Eliminates ground loop noise • Reduces most noise. Save: $6.96 $8.99. They do practicality eliminate all the low end distortion but lowerd the output voltage from at amp which sucks when you purposefully get HU with 4v rca … Thanks , You Pay: Order within 9 hrs 4 mins to ship today. Passive subsonic filter, EE's help? ... You could use the Harrison labs RCA HPF for them, which would be easy. Hlabs provides contract manufactures for partner companies. I have much higher end amps in my vehicles that include a subsonic filter and didnt realize how bad not having one distorted infinite bafffle subs. Discussion in 'Amps and Cabs [BG]' started by zagnut, Mar 16, 2009. List price $15.95. This switch is used in a bridged monoblock connection. Inputs / outputs: unbalanced (RCA) Subsonic Filter: switchable (at bottom) MM / MC input: switchable (at bottom) Includes resistor pairs, which you insert into sockets on the bottom of the chassis for loading options of 51 ohm, 200 ohm, 402 ohm, and 1 kohm Subsonic – it’s the same high-pass filter (HPF) on the sub amplifiers (often on monoblocks) – cuts off infrasound. 4.5. Master is set on the amplifier, to which RCA from the radio is connected, Slave is set on the connected monoblock. The natural rolloff at lower frequencies iscall you need . Bass boost. I've seen the PFMOD's adjustable filter, but not sure how well it will work with the signal being converted from 1/4" or XLR to RCA. "Harrison Labs FMOD Inline Crossover Pair 20 Hz High Pass RCA" from www.parts-express.com!