Direct Mounted pickups

[Cagey]

So the key question here is, "how do different PU mounting methods change the relationship between the vibrating string and the PU's magnetic field?".

For all intents and purposes, there is no effect. You could probably prove that there is mathematically, but it wouldn't be useful knowledge in the practical application. The ratio of string vibration to pickup vibration is too wide. Then, even if it weren't, you have to consider that audible vibrations move slowly, while magnetic field disruptions do not. So, even if the sympathetic vibrations of the body transferred to the pickup caused it to move a discernible amount, it's highly unlikely the signal would be anywhere near in phase, and in fact would likely be out by several cycles or more. So, you'd constantly have cancellations and augmentations of the signal going on that would be impossible to predict due the wide variations in frequencies produced.

 

[dNA]

So Alfang. If I do not know what I am talking about, then how could a pickup vibrating in the same increase the the signal in the coil, would not a magnetic field that is still be effected more than a one vibrating with the string
and yes the reason we use the magnets we do is to balance the amount of field to the pull of the mags on the strings, that is why we have adjustable poles
Do we need to get into the Permeability of the strings and the distance of the pole from the string, or the polarity, how about the way the magnet is laid out such as flat in a P90 or in the middle of the coil as in a Fender single coil, then there is the unique layout of the early Gibson CCs where they ran the direction of the strings.
A pickup vibrating around is Garbage in Garbage out.
Now the way the vibration of the spring is effected to create the signal in the field is the concern (we are saying if the pickup is properly installed and is of good design.)
the density of the wood, the joint in the neck, the quality of the hardware all will effect the string vibration.
Not wanting to get into the harmonics of the string and where the node/antinode lines up and the placement of pickups. I simple stated that a solid mounted Pickup would get a better reaction from the string than one that was vibrating in sinc with the string

I just want to make sure I understand, because I couldn't follow the syntax of a few of your sentences.

Your argument is that the pickup itself has the potential to move when it is mounted by springs on a pickup ring or pickguard? And if the pickup itself moves while the strings are vibrate, this affects the relationship between the strings and the magnetic field and thus impedes (not electrically speaking) its ability to transduce that signal from a magnetic field into electricity?

I think that is sound logic, but I don't think a pickup being mounted by springs is any more or less likely to move than one mounted on foam or even straight to the wood. I think any affect, while scientifically plausible, would be negligible.

 

[Jusatele]

I am saying that a pickup solidly mounted has a field that is stable and that the vibration of the springs has a greater effect of transferring a more pure signal to that than one that is vibrating around. That is simple? How much a properly installed pickup on springs is effected by vibration is not in my argument. I also think there are a lot of factors besides mounting that effect a pickups harmonics and tone, such as where it is placed, ever notice 2 of the same pickups sound different bridge to neck? There are so many factors that effect a pickup, getting the mounting correct is just a base. one that is slapping around will never sound right, Solid, foam, or a good quality spring should dampen movment of the PU.

 

[Cletus]

So Alfang. If I do not know what I am talking about, then how could a pickup vibrating in the same increase the the signal in the coil, would not a magnetic field that is still be effected more than a one vibrating with the string
and yes the reason we use the magnets we do is to balance the amount of field to the pull of the mags on the strings, that is why we have adjustable poles
Do we need to get into the Permeability of the strings and the distance of the pole from the string, or the polarity, how about the way the magnet is laid out such as flat in a P90 or in the middle of the coil as in a Fender single coil, then there is the unique layout of the early Gibson CCs where they ran the direction of the strings.
A pickup vibrating around is Garbage in Garbage out.
Now the way the vibration of the spring is effected to create the signal in the field is the concern (we are saying if the pickup is properly installed and is of good design.)
the density of the wood, the joint in the neck, the quality of the hardware all will effect the string vibration.
Not wanting to get into the harmonics of the string and where the node/antinode lines up and the placement of pickups. I simple stated that a solid mounted Pickup would get a better reaction from the string than one that was vibrating in sinc with the string

you are assuming ther vibration is in sync, rather than magnifying the overall level of vibration?

 

[Jusatele]

read above

 

[AGWAN]

For a second I thought we were going to see a knife fight here!

 

[Cletus]

I am saying that a pickup solidly mounted has a field that is stable and that the vibration of the springs has a greater effect of transferring a more pure signal to that than one that is vibrating around. That is simple? How much a properly installed pickup on springs is effected by vibration is not in my argument. I also think there are a lot of factors besides mounting that effect a pickups harmonics and tone, such as where it is placed, ever notice 2 of the same pickups sound different bridge to neck? There are so many factors that effect a pickup, getting the mounting correct is just a base. one that is slapping around will never sound right, Solid, foam, or a good quality spring should dampen movment of the PU.

"Pure" signal? There is signal, or there is a lack of signal. I just don't buy the argument on this one. Happy to be proven wrong though, I really don't much care either way.

 

[Jusatele]

more than likely the wrong adjective, but it worked

 

[Alfang]

OK Ok Ok, I'm splitting atoms here, cagey, I do agree with you , the amount of any movement on the pups is so minimal as to probably be of no value. Except back to my first post, those solidly mounted pups sound different, and mounted to foam is not solid mounted.

All's i'm sayin is this and take it for what its worth, ( nothing in reality ) the influence of the strings on the magnets is equal to the influence of the magnets on the strings

ie....all action has an equal and oposite reaction, So to say the pups don't vibrate is crazy talk, the whole damn guitar vibrates.

 

[Disco Scottie]

I'm just hoping someone can answer this question: when I go onstage, should I hairspray my hair, or just keep it natural? It's such a tough choice... have any of you dealt with this?

 

[drewfx]

So the key question here is, "how do different PU mounting methods change the relationship between the vibrating string and the PU's magnetic field?".

For all intents and purposes, there is no effect. You could probably prove that there is mathematically, but it wouldn't be useful knowledge in the practical application. The ratio of string vibration to pickup vibration is too wide.

Yes, that was my feeling - the ratio of PU movement to string movement has to be a fairly large number.

Then, even if it weren't, you have to consider that audible vibrations move slowly, while magnetic field disruptions do not. So, even if the sympathetic vibrations of the body transferred to the pickup caused it to move a discernible amount, it's highly unlikely the signal would be anywhere near in phase, and in fact would likely be out by several cycles or more. So, you'd constantly have cancellations and augmentations of the signal going on that would be impossible to predict due the wide variations in frequencies produced.

I'm not so sure here. At first I was thinking pretty much this same thing as well - that you'd perhaps get (if anything at all) a comb filtering effect from differing amounts of phase delay. But the propagation speed through a solid is much higher than in air, which means the wavelengths get correspondingly longer, which means a more consistent phase effect for relatively closely spaced frequencies. And the highest frequencies with the shortest wavelengths, where you'd get the most "random" phase delay (and thus comb filtering), would probably be absorbed by the wood anyway. Which leads me back to questioning why this should make any difference at all.  :icon_scratch:

I just can't see how it could have any effect that would be much different than what (maybe) a few dB's of EQ adjustment would cause.

 

[Strat Avenger]

I would challenge anyone in a blind listening test between a ring mounted pickup, and one that is screwed into the wood of the body (same guitar, same distance from the strings) to be able to hear any difference. It just ain't gonna happen -- Electrical Engineering Degree or not.

 

[tangent]

OK Ok Ok, I'm splitting atoms here, cagey, I do agree with you , the amount of any movement on the pups is so minimal as to probably be of no value. Except back to my first post, those solidly mounted pups sound different, and mounted to foam is not solid mounted.

All's i'm sayin is this and take it for what its worth, ( nothing in reality ) the influence of the strings on the magnets is equal to the influence of the magnets on the strings

ie....all action has an equal and oposite reaction, So to say the pups don't vibrate is crazy talk, the whole damn guitar vibrates.

I am also an electrical engineer, and one who specializes in electromagnetics and transmission lines at that, so I am pretty familiar with these kind of matters ; )

I think what you are not understanding Alfang, is that the strings do not act on the magnets directly.. at least not in the sense that you are talking about when trying to apply newtonian mechanics.

What the strings do act on, is the magnetic field emanating from the magnet.. and you could say that it is the 'influence' of the changing magnetic field on the magnet that generates the electrical current which is the whole point of the pickup.  In other words, if the strings were to physically influence the magnet in the sense that you were talking about before, then energy would already be conserved and there would be no current generated.

Of course the strings do act on the magnet indirectly as their vibration causes the entire guitar to resonate, but as Cagey alluded to the actual way the guitar resonates is extremely complex involving many vibrational modes across different parts which may be in and out of phase with each other at different times.. so it is impossible to say exactly what effects will result from the vibration of the pickups since that is a time-dependent thing and an intractable problem basically.   What can be said about it however is that the effects will be mostly negligible and any effect there is would only matter with respect to the highest overtones.

In my mind, the real downside to direct mounted pickups is that humbuckers are inferior and single coils usually look ugly when direct mounted =)

 

[Super Turbo Deluxe Custom]

If going the pickup ring or pickguard method, would rubber tubing instead of springs make a difference?

Also, I've heard on more than one occasion that a pickup does not even need a magnet to work.  To induce a voltage, my electrical training taught me that you need 1.) relative motion 2.) a magnetic field 3.) a conductor.  How could a pickup work without a magnet?

 

[Cagey]

Then, even if it weren't, you have to consider that audible vibrations move slowly, while magnetic field disruptions do not. So, even if the sympathetic vibrations of the body transferred to the pickup caused it to move a discernible amount, it's highly unlikely the signal would be anywhere near in phase, and in fact would likely be out by several cycles or more. So, you'd constantly have cancellations and augmentations of the signal going on that would be impossible to predict due the wide variations in frequencies produced.

I'm not so sure here. At first I was thinking pretty much this same thing as well - that you'd perhaps get (if anything at all) a comb filtering effect from differing amounts of phase delay. But the propagation speed through a solid is much higher than in air, which means the wavelengths get correspondingly longer, which means a more consistent phase effect for relatively closely spaced frequencies. And the highest frequencies with the shortest wavelengths, where you'd get the most "random" phase delay (and thus comb filtering), would probably be absorbed by the wood anyway. Which leads me back to questioning why this should make any difference at all.  :icon_scratch:

The pickup isn't sensing any sound or vibrations through the air. It's having it's magnetic flux cut, which happens at essentially the speed of light. If you consider a single cycle of vibration, the current generated by that will be at the output jack long before the vibration of the string that did the cutting will have transmitted through the body or pickguard to have an effect on the pickup's physical position in space relative to the string.

 

[Cagey]

If going the pickup ring or pickguard method, would rubber tubing instead of springs make a difference?

The only valid reason I know of to use surgical or rubber tubing in place of springs is because it's easier to deal with. Those damn springs have a mind of their own sometimes, while tubing goes on and stays in place without help while you wrestle the screws into place. Problem with the stuff is it doesn't have the life expectancy of springs, eventually hardening and removing your ability to adjust height. Takes a long time, though, so I don't know if I'd worry about it too much.

Also, I've heard on more than one occasion that a pickup does not even need a magnet to work.  To induce a voltage, my electrical training taught me that you need 1.) relative motion 2.) a magnetic field 3.) a conductor.  How could a pickup work without a magnet?

It can't. You could make a pickup without a permanent magnet, but it would still need a constant magnetic field set up so you'd have to include some kind of power to energize an electromagnet. Because you'd need some huge batteries onboard or an external source of DC power, it wouldn't be very practical.

A pickup is essentially a transformer operating sorta inside-out. Any time you have current flow through a conductor, it generates a magnetic field. The inverse is also true. WIth a traditional transformer, inducing a current in the primary winding sets up a magnetic field which the core cuts through. When  the current changes in the primary, the lines of flux in the core expand or collapse depending on direction of current flow, and they induce a current in the secondary winding. Depending on the ratio of winds from primary to secondary, you will increase/decrease the current and voltage induced in the secondary.

A guitar pickup does the same thing, but the magnet acts like the primary and doesn't vary, the string acts like the core but does vary, and the windings are the secondary. Instead of varying the current in the primary, by using a magnet we have constant flux lines. Moving the core (string) then causes variations in the magnetic field as they cut through the lines of flux, and those variations are reflected in the secondary. The ratio is quite high - roughly 1:8000 - because the change is so small. It's that secondary voltage/current that we send off to an amplifier to be increased to useful levels.

 

[Jusatele]

disco scottie

that depends on the brand of hairspray you are sponsored by, Aqua net specifies the amount of spray and the length of hair, however Revlon only demands that a can be left next to the bass drum

 

[Jusatele]

I think there are bout 5 directions we are looking at this
and that seems to be the problem
first, let us look at how a pickup works both electrically and mechanically

A pickup is mechanically a magnet(s) and a electrical coil, the magnet or pole pieces, shape a electrical field that when disturbed creates a electrical chrge in the coil
Faradays law of Induction
That law, is valid in the pickup not generating any charge (noise) if the magnetic field is not disturbed, the only way that field is not disturbed is if their is not any ferromagnetic forces exerted on the field so it is stable.

Moving the strings which are ferromagnetic or the pickup around the strings will cause a signal. We do not want sounds not from the strings, we want to pick up the harmonics set up from the strings.

A simple experiment would be to screw a pickup to a board and  swing a metal object over it. when we hook up a meter to the pickup we see it is effected, now we lay the metal object on the board and swing the pickup, we see the same reading on the meter, If we mount the pickup on springs and swing the metal object while having a drummer play a beat on the board,we see the meter give us a different reading than the first reading, as  now we have more vibration.

so we have established that it is not how the disturbance is generated, but it is the disturbance itself that creates the signal. In other words a vibrating pickup will generate sound by itself if a string is near it. any vibration will disturb the magnetic field and cause signal which we turn to sound in the amp.

Now, we need to go to mechanical theory to see how a string effects the magnetic field, we need to see the harmonic vibration of the string, we go into a study of Node/antinode.
and how that is effected by the fret you are holding the string behind. We also have to look at the speed of the vibration and the planes of the vibration. Yes guitar strings vibrate on multiple planes. These forces effect the signal generated. To complicate maters we have the forces of the magnetic field wanting to pull on the strings. Ferromagnetic strings are pulled on by the magnets we are using to create the field and in this dampen the string vibration so we need to be able to adjust the distance of the stings from the poles of the magnets, and there is a entire study in this and that is for another day., That is though, why most pickups are mounted as they are, not for the sound, but so they can be adjusted for best compromise. And even when they are adjusted, if the pickup has individual adjustable poles we can further tune it for the harmonics of the individual strings above them.

mechanically there is plenty of arguments for different mountings, and they are all compromises as seen in the last paragraph, Springs vibrate and create their own problems, foam compresses and has memory not wanting to expand out how it once was, surgical rubber breaks down with environmental forces like oils from your hands. If only one was the answer then we would all agree on it.

Then there is the effect of hardware and wood, we want the string to vibrate in a natural harmonic to create as pure of a musical signal as it can, any other forces on the pickup create junk. We need the hardware to be solid, with out movement, and have no dampening forces. That is why one style bridge can effect the tone the same as cheap bridges. the mechanical joint in the neck needs to be as solid as possible or it is absorbing vibration,
Woods all have tonal differences and these are because how dense the wood is and how it absorbs the vibration of the string.

Etc Etc Etc. We could discuss the thickness of a pickguard, the fingers vs plectrum, slide Vs fret, capos, and on but it gets redundant.

let us not forget personal style, we all use different techniques to dampen strings and voiding unwanted noise.

Now, how much each effects the sound, output power, and junk noise of the guitar is something that can be argued for years as every ones ear is developed differently. But I think I covered enough bases here to see that the more stable of a magnetic field we set up, the quieter the guitar will be (let us discuss 60 cycle hum later guys) and if we could create the perfect situation then it would not be a guitar.

 

[bob7point7]

I think there is a business opportunity here to start selling boutique pickup mounting springs. Example:

The 'Classic': This spring is wound on the same machine used by gibson from 1954 to 1963. We use only the finest steel wire held to exacting tolerances for thickness and hardness, then age each spring using our patented aging process to give it the damping characteristics those vintage Les Paul mounting springs are so well known for. The resulting comb filtering is the final step in achieving the ultimate LP tone.

The 'Hot Rod': This spring is wound with the same number of turns, but the overall length is 15% greater than stock, creating a higher compressed spring force which adds chime and airiness. Great for those particularly warm sounding guitars or for Les Paul Customs with mahogany tops. These springs are cryogenically treated for the ultimate in consistency and fatigue life. (Due to the increased difficulty of installation, we recommend purchasing our pickup mounting spring compressor.)

The 'Double Trouble': It's 2 springs in one! Our famous 'Hot Rod' spring has a second, reverse wound spring surrounding it. These dual concentric springs provide the ultimate in stiffness, simulating that early VH 'solid mounted' sound while allowing you to adjust the pickup height. We recommend using our nylon reinforced pickup rings with these springs for total mounting stiffness (and tonal bliss)!

Sorry, I just couldn't help myself.

 

[drewfx]

The funniest thing about this thread to me is, when I read some of the arguments, I feel like they suggest that the "best" mounting style is the opposite of the one the person intends to argue in favor of.  :laughing7:

And though I'm skeptical that any mounting differences could make much of an audible difference, even if it does, "different" and "better" are not the same thing.