So.....Edumicate me on bass HPF pedals.....

Discussion in 'Amps and Cabs [BG]' started by Analogeezer, Sep 21, 2021.

  1. Analogeezer


    Jul 29, 2021
    I don't need to know what they are, I did a lot of pro audio and studio work in the past, just about every mixer over $200 has a HPF (usually 80 Hz) on the channels to cut stage rumble from mics.

    I own a pair of racked vintage Calrec modules, from a 1970's mixing console. These have stacked HPF and LPF filters which use detented selection points. They are way cool mic pre/EQ's (there are also three band EQ's, they are input modules from an old Calrec, installed in two single rackmount enclosures. All discrete components, sort of a "British API" kind of sound.

    I use them mainly on guitar and the filters are great for "creating a frequency box" for guitar tracks.

    Seems a lot of you guys run these HPF filter pedals, hell Mesa includes on on a lot of their amps....which is cool.

    So I looked around a couple of common gear websites and I cannot even find these things for sale. Sure if I want an octaver, bass distortion, phaser, you name it they make a guitar style pedal for bassists, but these HPF pedals do not seem to be a common thing.

    It seems a company called Broughton (SP ?), makes these and they seem to be highly regarded here.

    Are there other units I should consider?

    Experiences with these and what is available would be some great information.

    My rational for getting one is I often use a small setup with a single 2 x 10" cab and that cab does not have a ton of low end, but my style is not a "lots of low end" style anyway and I don't play five string.

    Seems like a HPF would be a great addition to cut the stuff the cab is not producing at much volume anyway.

    So what do you guys have, use, recommend?



    p.s. I read a couple of threads here about these devices, they seem to be rather popular here but they don't seem to be popular enough for major retailers to even carry them
    Garret Graves, Zbysek and knumbskull like this.
  2. Jazzdogg

    Jazzdogg Less barking, more wagging!

    Jul 29, 2006
    San Diego, CA
    TBer FDeck (Francis Deck) makes a wonderful variable high-pass filter/pre-amp in a couple different formats.

    I have two: one that I use with double bass, and one that I use with electric whenever I am using a head that doesn't have one built in.

    I am lucky that my Acoustic Image Focus has one built in. The two other heads that I am considering also have them (Mesa and Bergantino).

    A variable hpf is such a game changer that I won't gig without one.
  3. Mushroo


    Apr 2, 2007
    It's probably worth mentioning that a lot of amp heads have a fixed HPF, as an unadvertised feature. So depending on your make/model of amp head, you might already be using an HPF and just not know it.

    I personally have the combo HPF+LPF from Broughton. I didn't think I would like the LPF, until I tried it, and now I use it often. I find it is a more neutral/transparent alternative to the tone control on my passive basses. As you point out in your OP, LPF/HPF is a handy tool for putting your bass in the right "frequency slot."
  4. Analogeezer


    Jul 29, 2021
    Yeah it seems when it is built into a head it's going to be better than one powered by a battery or a wall wart, but I'm not shopping for a head anytime soon.

    But if I do, the Mesa stuff is pretty high up on the list.

    Jazzdogg likes this.
  5. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    I roll my own amps and just include one in nearly every build. Beside Josh Broughton's offerings, look at TBer @fdeck's, SFX in the UK, and Vong in Germany, who do a nice looking kit. If you want a whole preamp in pedal form including an HPF add Mesa and Genzler.

    I'm also working up a non-commercial open source one that will require soldering several SMT parts in relatively large and easy to hand solder formats. Details will be in my long Open Source Preamp thread in the Pickups and Electronics forum.
  6. Analogeezer


    Jul 29, 2021
    I don't own anything "modern" as in from the past 10 years, so if built in HPF's are a new thing I probably don't have one; the current lineup includes:

    1978 Acoustic 220 (I don't use this really except around the house)
    Ampeg B2-R
    Bugera BVP-5500 (sort of their take on the SVT-3 Pro)
    Ampeg SVP-Pro Tube Preamp through a QSC PLX-1602 (I do set the subsonic filters on the QSC to on)
    Acoustic B300HD (the GC House Brand one) - just got this, have not tried it out of the house

    I am thinking of buying a GR Bass 2 x 8" to pair with the Acoustic B300HD (which was purchased really cheap to tip my toe into the Class D waters) so I figure the HPF might be rather useful with that cabinet.

    As far as tone controls, I run mine wide open on all my passive basses, but of course do the thing with the Jazz bass of dialing back the bridge pickup knob just a tad. Otherwise that bass just sounds wrong.

    TinIndian and Mushroo like this.
  7. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    All Genz Benz amps included HPF’s (including a take on variable HPF’s on GBE-750/1200 and ShuttleMax models) going back 20 years.
  8. lug

    lug Supporting Member

    Feb 11, 2005
    League City, Tx
    I think I recall someone saying the Acoustic 220 has an HPF type function unless you bypass the Graphics equalizer via foot switch. But my brain is old now so......................
  9. bass12

    bass12 Turn up the Eagles - the neighbours are listening Supporting Member

    Jun 8, 2008
    Montreal, Canada
    I use both the fdeck and the Broughton HPF/LPF. Both work well. The fdeck costs less.
    Jazzdogg likes this.
  10. abarson


    Nov 6, 2003
    Santa Cruz
    @Analogeezer this might get more traction in the Effects section as you're looking for a standalone solution.
  11. Analogeezer


    Jul 29, 2021
    Good point, I guess I didn't post it there because I don't consider it to be an effect but that's where all the stompboxes live.

    I'm just surprised there are not more on the market. I mean I didn't expect a plethora of the things but I did expect to find at least one on the websites of the major gear retailers. But nope....

    projectapollo likes this.
  12. Funny you mentioned this. Several years ago, you and I swapped a couple of Posts on Class D heads. I had described my experience about a certain Genz Benz combo. I believe I said something about a latency when “digging in”. Could that have been the HPF kicking in? I was not aware at the time HPF was part of the internal architecture.
  13. micguy


    May 17, 2011
    Every decently engineered bass amp has a high pass filter in it. When you pluck a string, if you pass that signal unfiltered, there is a lot of subsonic stuff at the beginning of the note - amplify that and put it through your speaker, and you'll see the cone move a lot, but you won't hear much - it's a waste of power which endangers the amp and speaker if you turn things up. So, smart amp designers always have some form of high pass filter in an amp.

    Past that, if you try to run high level fundamentals through bass guitar cabinets, because of some tradeoffs inherent in almost all the bass guitar speaker cabinet designs out there (light and loud are more important (sell better) than extended low frequency response), the woofer will run out of excursion at relatively low power levels. When it does that, it generates harmonics, and some of those sound....muddy. It isn't the low frequencies themselves that sound muddy, but....their effect on the system that can't handle them creates mud. So, a lot of folks around here use a high pass filter to further attenuate some of the low lows in their signal, thus keeping things relatively clean at higher volumes. There are a lot of very devoted high pass filter people on here - for many gigs, you should have one, but not necessarily for all gigs.

    I play one gig where i use an amp. It's a very low volume affair (think coffee house, and you're in the ballpark). At that gig, as I don't ask for high power, and the speaker I use does fine with low frequency fundamentals at that volume, the high pass in the amp I use is plenty. On ampless gigs, I send a relatively full range signal to FOH - the capabilities of the PA (which do much better than a bass amp at reproducing fundamentals) are different than what you'd have with an amp - the FOH person handles the high pass filtering appropriate for that PA, rather than have me guess as to where to set a filter at. Hence my pedalboard doesn't have a dedicated high pass filter. If I played club gigs through an amp, I'd definitely have one in the signal path.
    Last edited: Sep 21, 2021
    Zbysek and agedhorse like this.
  14. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Since there can't be any true latency due to the architecture, what you may be perceiving is a combination of the amp voicing (including the HPF and possibly some dynamics) and the speaker cabinet. The HPF, adaptive dynamics management combined with the speaker cabinet design made this new generation of compact, high powered combos possible.

    Otherwise, I don't know what else it may be.
    Chain_Lightning and Zbysek like this.
  15. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    What Shuttlemax models have a variable HPF ?
  16. 75Ric

    75Ric Supporting Member

    Feb 13, 2019
    Another shout-out for the fdeck variable HPF. Always a pedal I bring and the first thing I use to tune to the room. An excellent piece of kit. I also use Broughton's LPF to cut out hiss. Both are useful pedals and both are well-made.
    Esteban Garcia and Zbysek like this.
  17. Zbysek


    Mar 23, 2017
    Czech Republic
    Many people here use either Broughton or FDeck units. Both are great.

    I own and use several products from Broughton. I own FDeck clone too.

    No need to look further.
    Esteban Garcia likes this.
  18. Jazzdogg

    Jazzdogg Less barking, more wagging!

    Jul 29, 2006
    San Diego, CA
    I hasten to add that although the variable high-pass filter is one of the primary controls I use to adjust my rig to suit the acoustics of each venue, using this control can also create a whole new palate of low bass "textures" when used in conjunction with an amp's "deep" switch or low bass knob, even when recording direct! . Bass Voodoo! ;)
    Passinwind and Zbysek like this.
  19. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    Not to mention the effect when using one on an amp that already has a fixed HPF onboard.
    Jazzdogg likes this.
  20. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    All ShuttleMax models have the variable "LF Boost" filter which was originally called a "LF Extend" filter but we changed the name to "LF Boost" after some players had trouble understanding the concept of low frequency extension.

    Actually, the concept goes back to the switched filters in the GBE-400 and the variable filters in the GBE-600 and NeoX-400, which were released for production at the end of 2001, so my 20 year recollection (and memory fortunately) is correct.

    ML-200 , NeoPak and later the Shuttle models which also had this filter but it was switched between 2 points rather than just being hidden and fixed, and the terminology was changed with the ML-200 era products to be LF Boost though the filters remained identical.
    Last edited: Sep 21, 2021
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