Pickup Resonant Frequency

[superheavyfunk]

How does this factor into the tone of a pickup, and what does it actually mean anyway?

Ive been looking at the specs of a pickup in one of my basses, and it says the resonant frequency is close to 3k... Makes me wonder what would happen if I cranked that frequency on my EQ. Would I create a resonant portal in space/time?

Probably (definitely) not. But that *would* be pretty neat.

 

[Killed_by_Death]

 

[superheavyfunk]

View attachment 3704143

Thanks for the post but this means nothing to me.

 

[fermata]

Pickups/guitar wiring form an LCR (inductance, capacitance, resistance) circuit. LCR circuits can be tuned to have a certain resonance--the above graph shows what that looks like; there's a spike in amplitude for a certain frequency.

If a pickup is wired straight to the jack, that spike is likely to be fairly high, both in amplitude and frequency (which is to say, harsh-sounding). By loading the pickup with additional resistance (pots) and capacitance (for instance, a turned-down tone control or a small loading cap, like .001 uF, in parallel with the pickup), the resonant peak's frequency can be shifted/lowered. (Basically, resistors and capacitors can move around the resonant peak and control how strong it is.) The additional resistance from turning back the volume control slightly or turning down the tone control to some degree will flatten out the resonant peak. But notice that when you turn the tone control all the way down to 0, the capacitor gets involved in the LCR circuit and retunes the resonant peak; turn the tone control up to, say, 2, and the peak flattens again (the capacitor plays less of a role and parallel resistance is doing the work of affecting the resonant peak).

So when people are looking for replacement pickups, they're often (unknowingly) looking for a different resonant peak; a simple tweak of the circuit's capacitance can accomplish that for less than $1! I'd recommend reading Helmut Lemme's 'Electric Guitar: Sound Secrets and Technology,' which explains all of this very clearly.

 

[superheavyfunk]

Pickups/guitar wiring form an LCR (inductance, capacitance, resistance) circuit. LCR circuits can be tuned to have a certain resonance--the above graph shows what that looks like; there's a spike in amplitude for a certain frequency.

If a pickup is wired straight to the jack, that spike is likely to be fairly high, both in amplitude and frequency (which is to say, harsh-sounding). By loading the pickup with additional resistance (pots) and capacitance (for instance, a turned-down tone control or a small loading cap, like .001 uF, in parallel with the pickup), the resonant peak's frequency can be shifted/lowered. (Basically, resistors and capacitors can move around the resonant peak and control how strong it is.) The additional resistance from turning back the volume control slightly or turning down the tone control to some degree will flatten out the resonant peak. But notice that when you turn the tone control all the way down to 0, the capacitor gets involved in the LCR circuit and retunes the resonant peak; turn the tone control up to, say, 2, and the peak flattens again (the capacitor plays less of a role and parallel resistance is doing the work of affecting the resonant peak).

So when people are looking for replacement pickups, they're often (unknowingly) looking for a different resonant peak; a simple tweak of the circuit's capacitance can accomplish that for less than $1! I'd recommend reading Helmut Lemme's 'Electric Guitar: Sound Secrets and Technology,' which explains all of this very clearly.

Thank you very much for this clear and concise reply. You've explained it very well - I think I understand now, and I'll check out that book.

 

[fig]

How does this factor into the tone of a pickup, and what does it actually mean anyway?

The resonant freq is the freq area where the pickup output is strongest, loudest. Kind of colors the overall tonality of a pickup. Gives each pickup its character.

Generally the lower winding pickups have a higher resonant frequency and are brighter. Higher windings (of the same design pickup) have a lower resonant freq and are darker.

I used to put stock into a pickup's resonant freq until I learned more about it but, as fermata explained, once you start putting components in (pots, caps), everything changes dynamically with the twist of a knob. And, as fermata mentioned, the basic unencumbered pickup resonant freq is easily tweak-able.

Makes me wonder what would happen if I cranked that frequency on my EQ. Would I create a resonant portal in space/time?

Oh, yes, it's a thing. It's how I got to this altered space/time dimension. I know you have questions, but the differences between my old dimension and this one are minimal. The most major change is that in the old dimension, disco was never invented. So, there's that...

 

[superheavyfunk]

Oh, yes, it's a thing. It's how I got to this altered space/time dimension. I know you have questions, but the differences between my old dimension and this one are minimal. The most major change is that in the old dimension, disco was never invented. So, there's that...

What is the resonant frequency of your old dimension? I wouldn't mind traveling to one in which funk wasn't killed by it's lame younger sister.

 

[Passinwind]

Thank you very much for this clear and concise reply. You've explained it very well - I think I understand now, and I'll check out that book.

Here's a relevant piece of that book: Link Removed

You might also get something out of this thread, pardon the blatant self promotion: The Passinwind Open Source Preamp

 

[littlebun]

How does this factor into the tone of a pickup, and what does it actually mean anyway?

Ive been looking at the specs of a pickup in one of my basses, and it says the resonant frequency is close to 3k... Makes me wonder what would happen if I cranked that frequency on my EQ. Would I create a resonant portal in space/time?

Probably (definitely) not. But that *would* be pretty neat.

I like altering the resonant frequency on each of the pickups on my Alembic Series 1 Bass. To set the tone I listen to each pickup singly. I boost the gain switch all the way to 9db, and sweep the frequency knob. I play the bass listening and finding the best position of the Freq knob that adds clarity across all the strings. The max frequency is up to 6K on Alembics. For the bass pickup I tend to favor the mid-point of the Freq pot rotation, which is probably 2K or below. This is because on the bass pickup the higher Freq pot settings going toward 6K only adds clicks and noise, and doesn't seem to affect or help the fundamental note very much. For the treble pickup I tend to be at apprx @ the 2K setting on the Freq pot, as anything above that is clicky. Then I back off the gain switch for each pickup to the 6db setting. You would probably like the Lemme State Variable Filter. Aktive Elektronik: State Variable Filter I have installed one of the Lemme Filter's in a box and love it. It works very well for direct bass output, and adds an almost amp-ish tone to your DI output. If you're going direct just plug into the Lemme and then into a direct box. I like it especially when I'm going in-ears with no amp. It's fantastic for that as Lemme selected a lower input impedance for his filter preamp (330K) and this dumbs down the highest unusable clicky treble.
I have Neve and Telefunken preamps for my bass and the Lemme is right there with them. It's basically a mono filter just like the Alembic, and runs on 9 or 18 volt battery.