From TalkBass Wiki
This is the original "Passinwind" crossover that is frequently referenced in the fEarful threads, and has now been superseded by the Cheap But Goodâ„¢ design from greenboy. In the early days of the 12/6 evolution I built three prototypes from a set of experimental SPICE models I put together with help from this site, based on greenboy's request for a robust, low parts count crossover design for the 6ND410 equipped 12/6. This is the one I liked best of the three, and I used it nearly every day when I still owned my fEarful 12/6. Frankly though, it's overkill, and also heavy and expensive. And as far as I know nobody else has actually ever built one as spec'ed, so caveat emptor. ;^}
Note the non-reversed mid driver connection. RTA testing and my ears both like it better that way, while the textbooks and some models say otherwise. I would highly recommend trying it both ways if you build one. BTW, greenboy's later modeling of this design in Passive Crossover Designer software looked reasonably good (the model looked better with reversed polarity, FWIW), but I probably would have done things a bit differently if I had been using his modeling protocol back when I built this.
The nominal electrical crossover point is ~680 Hz, second order low pass, third order high pass. Midrange driver attenuation = ~8.2dB. System impedance can be considered 8 ohms nominal.
Sound Clip of fEarfulâ„¢ 12/6 w/Passinwind Crossover -- EUB
Signal chain: BSX electric upright -->Passinwind 5B preamp -->SpeakerPower SP1-1000 power amp -->fEarfulâ„¢ 12/6 -->Audix TR-40 mic @ 1ft, centered between mid driver and woofer -->Crest XR-20 mixer -->E-MU 1820M soundcard.
Sound Clip of fEarfulâ„¢ 12/6 w/Passinwind Crossover -- Distorted Slide Bass
Signal chain: as above, but with Travis Bean fretless bass, plus add Boss GX-700 modeler w/Hafler T-2 tube preamp in EFX loop -->Passinwind 4B preamp in EFX loop of PW 5B, SM-57 instead of TR-40 mike. You're listening to the quasi-guitar part, right? :^}
Parts:
Jantzen C-Coil 14 Gauge 3.9mH Inductor
Jantzen 18 Gauge 1.4mH Air Core Inductor
Solen 400v 47uF Polyester Film Capacitor
Solen 400v 16uF Polyester Film Capacitor
Solen 400v 12uF Polyester Film Capacitor
TWO: Mills Non-Inductive 10 ohm 50 Watt Resistors
ONE: Mills Non-Inductive 5 ohm 50 Watt Resistor
Welborne Labs Turret Boards
--Passinwind
back to fEARful
