Mismatched coil

[bbsailor]

Thanks Joseph, but the circuit is more than a single resonance. You can identify at least three, the two self resonances, each involving a coil and its self capacitance, and a lower frequency resonance involving the cable capacitance and both inductors. A true analysis of this circuit must consider all the components at once, and could be done by direct analysis or by using a program such as Spice.

Mike,

I understand that these resonances work together to shape the resonant hump to include the different resonances of each coil plus the combined coils. However, take into account the Fletcher Munson curve Fletcher-Munson Curve Explanation which shows the perceived equal loudness at various listening levels. At low levels the bass frequencies need more boosting to sound equal to the mid frequencies. The ear is most sensitive between 1Khz and 6Khz but takes its lowest dip on the Fletcher Munson graph between 3Khz and 4 Khz where many guitars exhibit a pickup resonance.

I would be interested to see how a Spice model would differ from a simple single resonance model. The extra sensitivity of the ear in the 3Khz to 4Khz range (upper harmonics but not the primary frequencies of the guitar) probably makes your complex Spice model more accurate but the ear is the final judge. Placing two coils resonance about 1 Khz apart can only broaden the resonant hump and lower the coil Q slightly. However, the conceptual issue is that the common coax cable capacitance value swamps (50 pf per coil vs 300 pf for the coax) the individual resonance of each coil with only its self winding capacitance.

[LtKojak]

There was a discussion of this showing the theory, measurements, and sound clips.

I haven't been able to find it... would you be so kind to point me to it?

Thanking in advance,

[Mike Sulzer]

I haven't been able to find it... would you be so kind to point me to it?

Thanking in advance,

Sure, I will look later after the Monday rush is over.

[Mike Sulzer]

I haven't been able to find it... would you be so kind to point me to it?

Thanking in advance,

oneCoilTwoCoil.mp3

The discussion is located at Sampling the string: differences between single coil and humbuckers

The attachments there are gone, and I cannot figure out how to get hold of the discussion so that I can put them back. I have attached the mp3 file that goes with the first post here.

[LtKojak]

[ATTACH]25760[/ATTACH]

The discussion is located at Sampling the string: differences between single coil and humbuckers

The attachments there are gone, and I cannot figure out how to get hold of the discussion so that I can put them back. I have attached the mp3 file that goes with the first post here.

Thank you very much, Mike.

Appreciated bunches!

[thetubedude]

Exellent retort! Thanks.

Excellent retort. Thanks for speaking up.

I'm not an expert, but honestly in this forum I read a lot of exaggeration:

1. The type of wire don't influence the sound, so poly pickups is the same of plain enamel pickups.
2. Polished magnets sound the same of rough cast
3. Mismatching coil isn't important.

So pratically the only thing that is important are the resistance of pickups. So a chinese pickups with 7 kohm and alnico V sound the same like a old paf that measures 7 ohm...

But anyone that have "hear" some pickups know that all this 3 point are important for a sound of pickup.

[Mike Sulzer]

Excellent retort. Thanks for speaking up.

I am not sure of your level of snark, but I do not think anyone is implying that only resistance matters. Everyone knows that if you wind with #42 and #44 to the same resistance, you have a significantly different number of turns, and so a difference in resonant frequency. And if that resonance is at a frequency where human hearing hearing is very sensitive, (as it usually is) then the difference in frequency response matters. Same resistance, different sound.

Some people do have a difficulty with assigning the most useful "cause" for a change in sound. For example, there are several ways to change the resistance of a pickup. They do not all give the same change in sound. Therefore, you cannot uniquely connect a change in resistance to a particular change in sound. You need to dig deeper.

I do not think that any of the three things that Marco mentioned are fundamental in the same sense as "changing the frequency response". Thus all three do not give unique changes in sound when they are varied (except under exactly the same other conditions), leading to different opinions as to their importance.

[Jim Darr]

...a hb p'up's sonic outcome is the result of the interaction of so many variables that's almost impossible to determine what everything does. Plus, there are many things happening inside a p'up that affect the sound that can't be measured because there are no instruments, no processes and no standards to measure'em.

Remember: "Not everything that can be measured counts, and not everything that counts can be measured".

Seymour Duncan, together with his chief engineer, Kevin Beller, have developed a computer controlled, forensic test and measuring environment capable to take a "sonic footprint" of a pickup that allow to replicate it afterwards. It's been used to make the "Pearly Gates", "Slashs" and "Joe Bonamassas", just to name a few. That tone footprint is an ensemble of parameters that can be mathematically altered in order to make a copy with the materials and processes available. If they have something like it, WHY do you think the testing is done by REAL PEOPLE with REAL EARS before signing off to production? Because you can predict math, but not a p'ups behaviour.

Trial-and-error is the only way to actually MAKE a p'up. All the ones that think otherwise are clearly in error, believe it or not.

The HB is a very complex pickup with ALL the variables having an affect on the tonal response. I developed my "Play Book" over time and continue to refine it. Some of my design changes got the results I was after, but many didn't sound like what I was expecting. Trial and Error, along with taking detailed notes an each experiment, helps get the sound I want.

[thetubedude]

Thank you

Thank you for your considered response. It was thoughtful and informing.
Many things in physics can only be observed and not yet defined.what you say is settled law and obvious.

I am not sure of your level of snark, but I do not think anyone is implying that only resistance matters. Everyone knows that if you wind with #42 and #44 to the same resistance, you have a significantly different number of turns, and so a difference in resonant frequency. And if that resonance is at a frequency where human hearing hearing is very sensitive, (as it usually is) then the difference in frequency response matters. Same resistance, different sound.

Some people do have a difficulty with assigning the most useful "cause" for a change in sound. For example, there are several ways to change the resistance of a pickup. They do not all give the same change in sound. Therefore, you cannot uniquely connect a change in resistance to a particular change in sound. You need to dig deeper.

I do not think that any of the three things that Marco mentioned are fundamental in the same sense as "changing the frequency response". Thus all three do not give unique changes in sound when they are varied (except under exactly the same other conditions), leading to different opinions as to their importance.

[SkinnyWire]

It's not the resistance itself, so much as what it infers relative to other parameters that makes it satisfactory as part of the discussion. Talking resistance with a potential customer is a foundation that most of them relate to, at least on some level, if for no other reason than it's the most popular current baseline. What you know about your own product relative to resistances provides you one angle with which to communicate with potential customers to try to tailor a solution to their problem (e.g. altering/improving the sound they hear from their current set up). It's fun to talk ad nauseam here about how insignificant resistance is in the grand scheme, but the fact is that it has significance in relation to the other measurable parameters. I'm sure the first person to have thrown out in public the phrase "resistance doesn't mean anything ... " patted himself on the back for summarily dismissing anyone who from that point forward uses the measure in any discussion of pickups as somehow uneducated regarding pickup making and design. Good for the ego, but no more useful in the long term than what they feel resistance is as a parameter. It's a valid piece of the puzzle.

[David Schwab]

1000 turns with #42AWG is quite a lot, where the same amount of #44AWG is almost nothing.

No, they are both exactly the same; 1000 turns. Are you thinking of the resistance? Don't go by that.

This is like the question; what weighs more, a pound of feathers or a pound of lead?

[David Schwab]

I'm not an expert, but honestly in this forum I read a lot of exaggeration:

1. The type of wire don't influence the sound, so poly pickups is the same of plain enamel pickups.
2. Polished magnets sound the same of rough cast

Some people say those things sound different.

3. Mismatching coil isn't important.

That's not true. With a humbucker you have a differential setup with the two coils. The distance between the coils is small enough where you have some high frequency cancelation. Mismatching the coils reduces that. As you move the two coils farther apart the notch shifts down. You can hear that on a Strat when you are in the 2 or 4 position on the switch.

So pratically the only thing that is important are the resistance of pickups.

That's the least important thing.

So a chinese pickups with 7 kohm and alnico V sound the same like a old paf that measures 7 ohm...

No.

[big_teee]

David S.
Where have you been Stranger?
Playing music, making Fame and Fortune?

[David Schwab]

Working my butt off! And playing music.