I Mean, Look

[beaubrummels]

You don't want to just have a set of capacitors, that's like having the tone rolled all the way off all the time. The cap sets the corner frequency, not the amount of roll off. You would need to experiment with resistors in series with the cap to figure out what combination makes a worthwhile pre-set.

[Seashore]

Set-and-forget options work well for me on guitar, but being able to fine tune is more important on bass. I don't use a tone knob on my setups but I have dual volume controls, and I make use of the various degrees of blending a lot. It's especially helpful when I'm recording. A little bit of a nudge can make the difference between supporting a mix or disappearing.

[Chistopher]

On an active bass, it's definitely better to have knobs for boosting frequencies, but I've seen a few passive basses that had a treble switch.

[Mincer]

Yes, this sort of thing can be done, and has been done in guitars, too. I love all the different shades across a variable tone knob so it wouldn't work for me, but there are a lot of people it would be perfect for.

[jeremy]

welcome to the forum!

you could absolutely make a tone switch with varying degrees of frequency roll off. im much more of a guitar player, but im used to using my tone knobs, and like being able to subtly dial in how much high end i want. i dont typically bump my tone knob while playing bass, but im a blues/rock guy so im not thrashing around too much when playing bass.

[oquintan]

Why couldn't you instead of having a traditional linear tone knob on a straight P Bass, have a 3 position selector switch with 3 different capacitors in parallel with the volume knob?
The tome is probably mostly created in pedals and amp settings, is the tone knob really the center of the universe, having a selector switch eliminates the tone knob getting accidentally turned during playing?
I'm just thinking out loud I guess.

Oscar