Consider a non-active humbucking neck pickup of brand X. Can I use EQ to make it sound like a different brand, Y?
Short answer:
Sorta. But there are limitations, and you would need to know some specifics about both pickups. You can even use some mastering tools like match eq plugins to do this to an extent.
Long answer:
How much time you have?
This is a difficult question to answer.
An electric guitar forms an RLC circuit with the cable and the input stage of an amplifier. RLC circuits are complex, and all elements of the circuit must be considered together to understand the behaviour of the circuit.
A pickup is just one component of the RLC circuit. How any pickup “sounds” depends upon its interplay with the rest of that circuit. A pickup has no “sound” that can be understood removed from the rest of that circuit.
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It’s mostly just the cable capacitance combined with the winding capacitance that is responsible for creating the resonance frequency (cable capacitance being far more substantial) with any additional series resistance including the pickups own dcr affecting q at resonance, But this is a little different from the pickups eq response when viewed by say a spectrum analyzer. The amp can be taken out of the equation for the most part except for any additional loading effects that it may present to the pickup, which will mostly serve to dampen the peak at resonance more.
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Yes, so RLC circuits are linear, hence I think it means that EQ should be able to make one brand sound like another (assuming similar size).
This is a really interesting question, a friend of mine is a jazz guitarist that only uses a neck pickup, and he was going to swap in a boutique brand, and this got me wondering…
Thanks. I’m not an expert in this and it’s been years since I studied circuits.
My point was that talking about the “sound” of a pickup isn’t really meaningful outside of the context of the circuit. This was my understanding, and it’s consistent with some things I’ve been told by people who design and manufacture pickups.
Would you agree with that assessment? As I said I’m not an expert on this and I don’t want to spread misinformation.
My understanding is that guitar amplifiers are nonlinear, and that his is essentially a necessity because the electric guitar is not a harmonically complex instrument.
Maybe @Fossegrim has some insights?
Not always in practice. Some can exhibit hysteresis, and keep in mind you are dealing with real components in practice not ideal. Even the materials used in the baseplate can exhibit loses.
You would be able to get a general idea with a match eq plug-in or something to that effect, but that would just sort emulate the eq, your not going to get other aspects captured that way.
This is an understatement.
Guitar amplifiers? They are non-linear because they historically are badly designed and were done so on a budget. But that’s what guitar players ended up loving about them!
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Thanks.
What I meant was that without the harmonic distortion of the guitar amplifier (due to nonlinearity) the electric guitar wouldn’t sound particularly inspiring, so the nonlinearity is basically essential.
Anybody who plugs a guitar direct with no amp and cab modelling, or who has plugged a guitar into a HiFi amplifier knows that an electric guitar is not a harmonically rich sounding instrument in and of itself.
This is kinda of a hard question, because so much of what we expect and are conditioned to like or accept is really kind of reliant on things working out the way they did. Some of it was serendipity. Is a guitar objectively a harmonically rich instrument on its own? I would say so, or at least it’s certainly not as boring as a theoretical pure sign. But of course it’s all reliant on what your really comparing it to.
Now comparatively, is it much more exciting when plugged into an amplifier that is being driven to all hell. Of course, and objectively you can see this as well. But if things had not quite turned out the way they did, and the same fads that were built along side of it or because of it hadn’t come and gone, would we be conditioned to accept it differently? If we never knew any better of it, would we still think it’s boring?
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Yes with EQ you can make a passive Humbucker sound like different passive Humbucker on the same guitar.
How do I know this - I wrote a profiling EQ plugin a few years ago - I used a FFT sized 4096
integrated the bin magnitudes over a short time period and then ratio matched with a “profiled” snapshot.
Sounds great - and I’m sure there are many other plugins that can EQ match.
You can also use the same method to get the final guitar tone - i.e. speaker after distortion.
What it can’t do is the Pre distortion EQ - which controls the dynamics hitting the clipping on a distorted sound.
It also can’t really make one guitar sound like another - because of the physical body resonances that differ and alter the string decay/harmonic decay.
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What I used to do in the studio, although this isn’t exactly what you asked, is eq the di and then reamp it. Mostly to correct some resonant frequencies. It made a difference for sure. So you could experiment with that, if you have a reamp box of course.
This falls into the with in reason clause I mentioned above with match eq’s. There are other aspects you will not be able to match. The dynamics of the pick up, and the width of it’s magnetic field/pick up area which will affect how it responds. If the information isn’t there to begin with, no amount of eq is going to add it back.
I disagree with you - both the magnetic width and dynamics of the pick will all be picked up in the profile. Since the pickup is passive - it acts just like static EQ from my tests when I did this. Because you are integrating over a short time period (10secs to 30 secs) all of that gets picked up. I suggest you write one in reaper JS and try for it yourself. It’s relatively easy to do from a code point of view, and I could point you in the right direction if you get stuck.
Two things. 1st, this might be a neat thing we can explore here. Especially for those who are interested in this side of MI. I am really curious what would happen with an active design we tailor to have a wide, flat bandwidth - how it responds to taking on different personalities so to speak.
2nd. And that’s okay. We will just have to agree to disagree then, only on a couple of things though. I do agree with you mostly, and it can get close enough to extremely close especially with two like things, and depending on application. The eq and dynamics of a pickup are not exactly static, and it does more than just react linearly to what it’s fed. if everything was truly static, the pickup would respond and sound exactly the same with a note, string etc. played at half amplitude as it would with the amplitude attenuated to the same level after the fact, and both permanent and ferromagnetic magnets exhibit nonlinear behaviors that are not easily captured using eq and level matching that those programs are designed to correct. Also if the information isn’t present to begin with, no amount of eq or level correction is going to restore it, it simply isn’t there to work with, and you are not working with a blank slate. One case - I have yet to hear a match eq fully able to transform a standard two side by side coil, humbucking design into the exact narrow field single coil it’s trying to profile. It ends up with attributes of what it’s trying to capture, but I haven’t heard one that is fully able to, at least not yet.
Now, thats not to say you can’t come extremely dangerously close, especially if you are matching two things that are more alike than not as the op is suggesting. In that case it’s way more accurate. But in general with match eq’s or any advanced listening DSP, you’re always working with essentially a small static snapshot, and you are not going to get every single little nuance that may (or may not) be there. Is it close enough for most people? Yeah, I’d say so.
Agree to disagree 
I stand by my static EQ statement!
I don’t know how other Matching EQ algo’s work - so maybe the issues you are talking about are down to a generic algo that generally covers all use cases well enough.
I also think it would be extremely difficult to prove a passive pickup is in fact non-linear or static without a ton of $$$$ gear.
It’s not ML as such there’s no sigmoid/bias or back propagation - let’s call it DumbML ™
Here’s the algo I whipped up - I forgot if I did raw magnitudes on the bins - or proper sin/cos mags:
This is the simplest version - completely static and works surprisingly well.
A possible improvement would be to use a leaky integrator instead and store multiple sets of ratio multipliers at constant intervals or when the target profile changes above some kind of threshold metric e.t.c. I found it good enough at the time to not try sets e.t.c. FFT was 4096 @ 48khz
- Capture Target Profile (the audio you want to sound like)
When playing Target Audio say 30 secs
Get a FFT frames worth of samples
Perform FFT
add FFT bins to Target profile sum array
- Capture Source Profile (the audio you want change)
When playing Source Audio say 30 secs
Get a FFT frames worth of samples
Perform FFT
add FFT bins to Source profile sum array
-
Divide Target profile sum bins by Source profile sum bins to get ratio multiplier for each bin - these are essentially your static EQ levels
-
Apply EQ Match
When Playing Source Audio
Get a FFT frames worth of samples
Perform FFT
Multiply bins by the ratio multipliers from step 3)
Perform IFFT
output Audio frame
Source Audio will be EQ matched!
** you can play around with overlapping and adding FFT’s for improved time or freq resolution.
Start coding!
I mean, there’s a number of issues at play here, and we’re already going pretty deep into one of them…
…but the other I think worth mentioning here is, I don’t think “brands” really have much to do with the sound of a pickup. You’re not going to plug into an amp and say, “Ahh… the distinctive Dimarzio low end,” or “that’s exactly the sort of midrange complexity I associate with Bareknuckle,” exactly.
I think you can use EQ to change the sound of a pickup, absolutely. I think it’s a LOT harder to make, say, an EMG sound like a PAF-style low output humbucker with EQ and gain alone. And I think making a Bareknuckle Holy Diver or a Dimarzio AT-1 sound like a JB (with the former two pickups being inspired by 80s JBs) is, well…
Other thing I’d point out here too is for me the “feel” of a pickup matters almost as much as the tone, how a pickup responds to varying degrees of pick attack, and that’s definitely not something you’re going to captyure with an EQ.
So, all in, no, I wouldn’t say that you can save money on a pickup swap by just tweaking EQ a little. You might get results you like by doing that, and I suppose in that case it’ll save you some money, but you’re not going to exactly replicate the tone and feel of a different pickup by sticking an EQ in line between your guitar and amp.
EQ can get you close to the frequency curve, and compression can change the transient response if you’re using, say, a ceramic humbucker and want to approximate an alnico single coil.
For all the technical reasons that those dudes mentioned above though, it won’t sound exactly the same!
Billy Gibbons famously uses (or used to) EQ to approximate the sound of his “Pearly Gates” Les Paul when he plays other guitars live (skip to 8m48s):
