Has anyone done this before? I was thinking some kind of passive or active filters instead of a tone control. Isn't a tone control basically a LPF anyway?
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HPF/LPF built into a bass?
- Thread starter Scott Shaw
- Start date
I thought about doing this at one point but it was easier to velcro an always-on HPF to the back of my amp. For gigs where I don't use my amp there is a sound guy who takes care of the HPF through the house system.
Passinwind
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- Dec 3, 2003
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Yep. Alembic and Wal are probably the two best known examples.
Im no sound expert, but I really doubt that a HPF does the same thing as a typical tone control. HPF passes the highs, and lot of tone controls (particularly older ones) IMO affect not just highs and lows, but presence. Maybe thats wrong or oversimplification but thats how it seems to me.
To my understanding, a typical HPF/LPF filters are gonna have a much steeper roll off at the cutoff point and have less effect over the soundscape in between than something like a tone pot.
I have LPF+HPF on my P/reverse P frankenbass. They are both push/pull, bypassed by default (push).
LPF is just a classic tone control, although I added 3 way switch with 3 different capacitors just for fun.
HPF is useful if sound is to boomy and you want to get rid of some sub lows. It is sometimes too much bass when I use P/P in series.
LPF is just a classic tone control, although I added 3 way switch with 3 different capacitors just for fun.
HPF is useful if sound is to boomy and you want to get rid of some sub lows. It is sometimes too much bass when I use P/P in series.
My Alembics (a Spoiler Five and an Elan Five) used a LPF, which depending on the tone knob position, would gate off anything above 350hz to 6khz. In practice, it seemed cleaner and smoother than a conventional tone knob, and completely different from cut/boost active tones. Dead simple, then you added tone at the amp if need be.
Move on into their Series axes and you can have selectable LPF/BP/HPF onboard, separate for each pickup, or replicate that tone control in a rack mount, the SuperFilter.
Move on into their Series axes and you can have selectable LPF/BP/HPF onboard, separate for each pickup, or replicate that tone control in a rack mount, the SuperFilter.
A HPF is an interesting notion but it's something I'd probably just add on to my amp or pedalboard as an always-on feature instead of built into the bass itself. It's not something I'd use in the studio or for rehearsals, just for certain finicky venues which get boomy. Same with a LPF, really. Unless I'm going to be plugging direct into the board for gigs (which is literally never going to happen), not for me.
I would be onboard (pun intended) if there were some controls involved. The way I set my HPF is with my ear. I start to play and gently, slowly, gradually, turn it up until the speaker cab simply "opens up". It's a remarkable thing, actually. When you hear it, you'll know it.
But the point is that I wouldn't want it set at one frequency. Just like any other aspect of EQ, "it depends". It depends on the cab, the room, the band, the bass, etc. So it's more practical for me to have an outboard Broughton Always On adjustable HPF right in front of my amp.
But the point is that I wouldn't want it set at one frequency. Just like any other aspect of EQ, "it depends". It depends on the cab, the room, the band, the bass, etc. So it's more practical for me to have an outboard Broughton Always On adjustable HPF right in front of my amp.
I have a DIWhy HPF in my P-Bass, and... well, it does work but the cutoff frequencies are anyone's guess. Wouldn't do it again as I frankly don't use it that much (and it pops pretty bad). It's a rotary switch with multiple value caps.
I’m of the opinion that HPFs and LPFs are more along the lines of signal fixers rather than tone enhancers. They’re basically there to cut out junk frequencies in your signal. And while useful, they really aren’t that useful as tone controls all by themselves. So I think they make more sense as outboard devices, either as a pedal, or built into your amp.
But high and low pass filters aren’t the only type of filter circuit. There’s a variety of resonant filters that make for extremely versatile tone controls. These filter based onboard tonestacks have been around for a good long while now. Alembic was doing them as far back as the early 70s.
If you’re interested in trying one out, and you’re up to assembling your own, take a look at this thread.
But high and low pass filters aren’t the only type of filter circuit. There’s a variety of resonant filters that make for extremely versatile tone controls. These filter based onboard tonestacks have been around for a good long while now. Alembic was doing them as far back as the early 70s.
If you’re interested in trying one out, and you’re up to assembling your own, take a look at this thread.
You might find this interesting: Aktive Elektronik: State Variable Filter
I’ve wanted to try one for a while, only thing holding me back is the expense of DE->US shipping
I’ve wanted to try one for a while, only thing holding me back is the expense of DE->US shipping
Yes, the generic tone control is a passive LPF. I would guess (not looking at the circuit) that the passive bass control on G&L basses is a HPF. I own an Azola EUB with a passive HPF.
It depends on how many poles the filter has. The active filters in analog synthesizers are usually 2 (12db/octave) or 4 pole (24 db/octave) but I've seen digital filters as steep as 8 poles (48 db/octave, practically a brick wall).
Yes, G&L's PBT (passive treble bass) system is an on-board LPF and HPF. However, passive HPFs are not as effective as active ones, because the roll-off isn't nearly as steep: just 3 dB/octave for passive vs. 12+ dB/octave for active.
My Starfire bass has an ACG EQ-01 preamp. Has a LPF per pickup and a blendable HPF, plus volume and pickup pan control. Love having that crazy tonal versatility right at my finger tips.
*Technically my Gibson Les Paul Triumph bass also has a LPF and HPF system but it's passive. Still remarkable range of tones available there because the pickups are low impedance with a step-up transformer.
*Technically my Gibson Les Paul Triumph bass also has a LPF and HPF system but it's passive. Still remarkable range of tones available there because the pickups are low impedance with a step-up transformer.
