# The importance of Pole Pieces Alignment with the strings



## DrJazz (Jul 22, 2012)

Hello all.

I'm having an 8-string multi-scale built. We're talking 28.625 to 25.5 inches, straight fret at 7, so the fan, at the bridge, is pretty huge. This has lead to some theorizing on the importance of the position of pole pieces with my luthier, and I'd like to bounce some ideas with you guys (and gals).

Since the fan at the bridge is intense and I intend to slant my pickups, the pole pieces will shift relatively to each string. This means that the pole pieces will be slightly higher or lower than their commonly accepted position, depending on their position on the pickup.

From what I've read, this would result in a slight loss of volume over all strings. I'm slightly sceptical, but it's the generally accepted concensus, so let's roll with it for the intents of this post. This loss of volume would be, however, pretty even on all strings due to the fact that all pole pieces shift. So volume reduction isn't especially scary, since it's even on all strings, and therefore easy to compensate.

Furthermore, if volume tends to drop when the strings gets further away from the pole pieces, having a pole piece slightly lower than the string and the other slightly higher would negate the theoretical loss of volume encoutered when bending. I know I haven't come across that problem, but I've read a few guitarist who've been playing for longer than I've been alive complain about this issue, so I'm not disregarding it. As a matter of fact, I'm wondering if slanting the pickups would not help resolve this issue.

Also, when we look at the agile pendulum models, unless I'm mistaken, the cepheus pickups are normal pickups that were simply slanted. Being the owner of a pendulum 8 myself, I've yet to experiment any sound loss when bending, or simply any tonal disagreement caused by my pickups. If we follow the previous reasoning, the pole pieces are not aligned, yet many players are fully happy with their stock pickups on their Pendulum. Are we collectively missing something? Or is pole piece alignment with the string not that dramatically important?


So, now that all the technical mumbo jumbo is said:
I've crunched some numbers, and I'd be looking at a 25 degrees slant for the bridge pickup. I've calculated that my pole pieces would barely overlap. This was calculated with the specs I have from BKP, because, ideally, I'd be looking at a Cold Sweat (N) and Aftermath (B) combo.


What do you guys think?
Taking into account everything above, would I be correct in supposing that the BKPs would still work in my build? Or am I completely screwed, and I need to buy "blade" pickups (ala Lace X-Bar)

Thanks!


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## Hollowway (Jul 22, 2012)

Good question. I have a similar thing going over in the OAF fanned 7/8 run:
http://www.sevenstring.org/forum/3102608-post717.html

I think what we need here is a pup manufacturer to weigh in. I've heard both ways - it makes a significant difference and it doesn't.


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## Rap Hat (Jul 22, 2012)

DrJazz said:


> Hello all.
> Also, when we look at the agile pendulum models, unless I'm mistaken, the cepheus pickups are normal pickups that were simply slanted. Being the owner of a pendulum 8 myself, I've yet to experiment any sound loss when bending, or simply any tonal disagreement caused by my pickups. If we follow the previous reasoning, the pole pieces are not aligned, yet many players are fully happy with their stock pickups on their Pendulum. Are we collectively missing something? Or is pole piece alignment with the string not that dramatically important?



I've never seen an Agile multiscale with slanted passives (non-Lace) and the active Cepheus are bar pups AFAIK. That's why people aren't having issue with volume loss.

There was someone that had some volume issues with their Lace though(fan was too large for them) and I read somewhere that Lace recommends putting their pickups in a certain direction on multiscales so you don't have volume loss due to how the bars are aligned.

My only "string-off-pole-pieces" experience was when I put my 7321's neck on askew and the high e was a bit quieter than the others. It wasn't even that far off, enough to effect it though.


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## Hollowway (Jul 22, 2012)

Yeah my experience is that I have a slanted humbucker in a straight fretted guitar (one of those '80s Kramer Pacer Customs). I never had any problem with it, and the pole pieces most definitely do not line up with the strings. But the word is that it does affect it, and that's why we never see pups lined up that way. That being said, with the paucity of pickups available for fanned and extended range instruments, the need is once again there, so I'm curious.


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## Durero (Jul 22, 2012)

I've had extensive experience, not to mention frustration, with trying to line up pole pieces under the strings on multi-scale designs.

Every pole-piece pickup I've tried exhibits dramatic changes in output with even small movement away from the directly under the string position.

It may help to think of the pole piece positioning as similar to mic positioning in a recording studio - small changes in position can yield big changes in output and tone.


To me having any of the pole pieces not perfectly aligned with the strings is a deal-breaker. I always want the option of hearing the strongest output from a given pickup and I can turn down the volume to lower the output. 

But others who prefer low output may be happy with the scenario of non-centered pole pieces. The crucial issue then becomes making sure that the distance from pole-piece centre to string is consistent across all the strings, and in my experiments this has never worked out because of the constant changes in string spacing caused by the string taper from bridge to nut.

To DrJazz I would highly recommend mapping out the geometry of your pickup pole pieces and your strings _before_ you start the build. I think you'll find that unless you have zero string taper (nut spacing = bridge spacing) then the pole-piece to string distances become very sloppy.


For those reasons I'd highly recommend rail type designs, or fully custom pole-piece pickups where every coil has the exact spacing for it's position under the strings. That means the two coils of a humbucker are _not_ exactly the same lengths; the coil closer to the nut is slightly narrower.

Check out Oni Guitars to see beautiful custom spaced pole-piece humbuckers on multi-scale instruments.


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## Hollowway (Jul 22, 2012)

Durero said:


> I've had extensive experience, not to mention frustration, with trying to line up pole pieces under the strings on multi-scale designs.



Perfect! I remember you made those individual string pickups for your prototype ERGs, so you're just the person to cast light on this.  

btw, that's an interesting thing you said about the two coils of a humbucker needing different interpole lengths due to string taper. That's a really good point, and although it's a minor thing, I'm surprised no major manufacturer has done it. At the very least it would differentiate them from other manufacturers.


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## bob123 (Jul 22, 2012)

Allow me to sesame street this a little bit.

Guitar pickups are generators, the steel strings are the motor action. As the strings vibrate, it cuts the magnetic flux which creates (albeit a small amount) of electricity, ergo your output. 

Pole peices lining up is 98.2% (made up number close to 100%) purely cosmetic (under normal circumstances, obviously on SOME angled pickups, if the magnet is inside the string, or far outside, it will have some effect on output)

Output is 100% defined by 
1) proximity to strings
2) strength of the magnet(s)
3) wire gauge
4) number of windings
5) string gauge and vibration intensity (sloppy strings = lower output, tighter/thicker strings = higher output, aggressive pick attack = higher output, etc etc)


Heres a diagram I made, not only does it not matter, the effect is lost because the strings arent sitting still, they are vibrating from side to side. 

Now, pole peices lining up WILL increase output due to its closer proximity to the magnet, however, this effect will be so intensely small that the human ear wouldn't be able to detect it.

Now, with angled pickups, that changes things of course. the closer to the neck, the closer you are to the middle of the string, which increases the distance the string vibrates back and forth. This is why neck pickups are louder. So this leaves your bass strings will be louder on angled pickups if angled on the bass side, and vice versa if angled on the treble side.


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## Durero (Jul 22, 2012)

And how does magnetic field strength change with distance from the magnet Bob? 


Magnetic field strength drops exponentially with distance from the magnet.

In the case of pole-piece pickups, so does the output.


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## snowblind56 (Jul 22, 2012)

I think it matters to a certain point, but I wouldn't be able to hear a difference. Also, what happens when you do a string bend?


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## DrJazz (Jul 22, 2012)

Rap Hat said:


> and the active Cepheus are bar pups AFAIK



Well That exaplins it! Thanks!



bob123 said:


> Output is 100% defined by
> 1) proximity to strings
> 
> ...
> ...



This is what I'm thinking as well.




Durero said:


> And how does magnetic field strength change with distance from the magnet Bob?
> 
> 
> Magnetic field strength drops exponentially with distance from the magnet.



Yes, the strenght of the magnetic field is linked to the distance. But then again, this distance is on two axis : the distance between pickup and string (so, let's name it the pickup height), and the one perpendicular to that (let's call it the pole-piece offset). Since only one of those changes, and not that much as a matter of fact (my string would still go over both pole pieces, from what I've calculated), would the magnetic field drop as dramatically?

Furthermore, if it's only a "volume" issue, can't we simply place the pickups closer to the string in terms of height? If the tonal response isn't changed (from what I understand), save from the volume aspect, by placing the pickups higher we could negate this.

Also, on the issue of string tapering, I would have thought it to be a non issue. In the most extreme cases (the 1st and 8th string), we're still talking about a pretty light angle, no?


Also, I've been talking with Matthew Brown from Etherial Guitars, and he build guitars in which he slants BKPs, and he hasn't noticed a tonal change by angling the pickups. For what it's worth.


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## bob123 (Jul 22, 2012)

Durero said:


> And how does magnetic field strength change with distance from the magnet Bob?
> Magnetic field strength drops exponentially with distance from the magnet.
> In the case of pole-piece pickups, so does the output.




I said that....  the effect is too insignificant to matter though. For a "real life demonstration", screw your pickup in 1 full turn. That should realistically demonstrate the difference between pole pieces being aligned, and not.


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## bob123 (Jul 22, 2012)

DrJazz said:


> Yes, the strenght of the magnetic field is linked to the distance. But then again, this distance is on two axis : the distance between pickup and string (so, let's name it the pickup height), and the one perpendicular to that (let's call it the pole-piece offset). Since only one of those changes, and not that much as a matter of fact (my string wouldetic field drop as dramatically?


 still go over both pole pieces, from what I've calculated), would the magn

Three dimensional field of course. The effect is based on how strong the magnet is. At some point the field is too small to matter. The fractions of a milimeter difference in pole peice alignments is far too small for it to drastically effect output. 



> Furthermore, if it's only a "volume" issue, can't we simply place the pickups closer to the string in terms of height? If the tonal response isn't changed (from what I understand), save from the volume aspect, by placing the pickups higher we could negate this?



point of diminishing returns though. you can only raise strings up to a certain height before the flux interferes with string vibration (wolf tones if you will). So you are limited in that aspect. A better way to counter act that is to simply use more windings around the magnet (and thats how pickups get "hotter", more conductor = more electricity = more output)



> Also, on the issue of string tapering, I would have thought it to be a non issue. In the most extreme cases (the 1st and 8th string), we're still talking about a pretty light angle, no?
> Also, I've been talking with Matthew Brown from Etherial Guitars, and he build guitars in which he slants BKPs, and he hasn't noticed a tonal change by angling the pickups. For what it's worth.



Yeah, tonality shouldn't change much, mostly just output.


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## Hollowway (Jul 22, 2012)

DrJazz said:


> Furthermore, if it's only a "volume" issue, can't we simply place the pickups closer to the string in terms of height? If the tonal response isn't changed (from what I understand), save from the volume aspect, by placing the pickups higher we could negate this.
> 
> Also, I've been talking with Matthew Brown from Etherial Guitars, and he build guitars in which he slants BKPs, and he hasn't noticed a tonal change by angling the pickups. For what it's worth.



Well, the problem with raising the pup height is, as Durero was saying, the pole pieces are not universally off center. They vary with how far they are from their ideal position under the string, so it's not so much a matter of decreased volume as differences in volume between the strings.

And I wouldn't necessarily listen to someone who is building guitars with pickups in that configuration, because even if he did notice a difference at this point I doubt he'd want to admit that the others were built with such a flaw. Not to say he's wrong, just that he's inherently biased.

Anyway, I am curious what the effects are, and at this point I still feel that Durero has the most to offer since he has empirical evidence for both ideal alignment and offset alignment. It seems most others have just theoretical arguments for or against. 

That being said, in the absence of a suitable replacement, I'd be willing to try a slanted BKP or something for an ERG.


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## DrJazz (Jul 23, 2012)

Hollowway said:


> Anyway, I am curious what the effects are, and at this point I still feel that Durero has the most to offer since he has empirical evidence for both ideal alignment and offset alignment. It seems most others have just theoretical arguments for or against.
> 
> That being said, in the absence of a suitable replacement, I'd be willing to try a slanted BKP or something for an ERG.



It's similar to my conclusion. I don't have any empirical evidence myself, and I'm not disregarding Durero's experience. However, I'm still curious about determining the exact extent of this effect, if effect there is, and I'll probably be buying a set of BKPs to put in my next build. We will see afterwards if there really is any difference.

I'll try to update this thread when everything is built, but we're talking a godd 6 months from now.

Holloway, if you're going to do something similar I encourage you to do the same, we'll be able to compare results!


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## wakjob (Jul 23, 2012)

It's OCD with me, I like my pole pieces lined up.

But, how about playing on a neck pu and bending a note on the strings. They are no longer lined up but still sound good.


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## WhiteWalls (Jul 23, 2012)

Just out of curiosity, how would it work with a pickup that does not match the number of strings on the guitar? Like putting a 6 string pickup on a 7 string, would it have a similar effect to this (lower output but similar tone)?


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## TRENCHLORD (Jul 23, 2012)

Slanted blackhawks (maybe in the works?) would look knarly, with the rail design, the output would be consistant unlike the misaligned pole spacing, right?


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## bob123 (Jul 23, 2012)

WhiteWalls said:


> Just out of curiosity, how would it work with a pickup that does not match the number of strings on the guitar? Like putting a 6 string pickup on a 7 string, would it have a similar effect to this (lower output but similar tone)?




correct.



TRENCHLORD said:


> Slanted blackhawks (maybe in the works?) would look knarly, with the rail design, the output would be consistant unlike the misaligned pole spacing, right?




slanted pickups increase the output towards where they are slanted, but you lose harmonics, just like the difference between a middle and bridge pickup.


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## ElRay (Jul 23, 2012)

*On-Topic:*
I have a 7-string I am in the process of converting to a wide-neck 6-string (same spacing as a "narrow" necked Classical), and all the strings cross the pick-ups between the poll pieces. With the original Schecter 7-string pick-ups, I have not noticed a difference on strings 2-4, but I have noticed an improvement on the top and bottom strings. That's easy to chalk-up to the effective elimination of edge effects.

I think one of the big complaints about straight pick-ups in a compound scale guitar is that the bridge pick-up turns into a "Tele-style" pick-up and a lot of folks don't like the "twanginess" introduced. Likewise, a straight neck pick-up will make your treble strings sound like a middle pick-up, which many don't like mixed with the regular neck pick-up sound of the bass strings.

*Slightly Off-Topic:*


bob123 said:


> I said that....


True, but if you had paid attention to both of Durero's posts, you would have seen that he didn't just ask you a simple question you already answered.


bob123 said:


> the effect is too insignificant to matter though.


In your (assumingly limited) experience. Durero's been around here a lot longer, has 5x the posts you have (not the end-all-be-all, but a factor), has been playing his custom compound scaled guitar long before there were any mass-produced multi-scales, is currently in luthier school, has tested several manufactures single string pick-ups, has been prototyping and testing his own single string pick-ups, etc. I think his observations count a bit more than yours. 

Also, your conjectures (do you even have any direct observations? Durero does) are just that: yours. They say nothing about anybody else's. If your strings are already close to the pick-ups, then the additional distance due to misaligned poles won't make much of a difference; however, if the strings are further away, or in a weaker section of the field, then due to the squared factor, that mis-alignment could indeed make a difference. In a big chunk of the cases, it likely won't, but that's a far cry from a blanket statement that the differences will be insignificant.

I think a whole lot depends on the pick-ups, the action, shielding, etc. That's why Durero recommended the magnetic detection paper. This way, you can visually see what the fields are doing in situ, at your string height, in your guitar.


bob123 said:


> For a "real life demonstration", screw your pickup in 1 full turn. That should realistically demonstrate the difference between pole pieces being aligned, and not.


That must be one hell of a coarse thread on the pole pieces. Most strings will vibrate a lot more than the typical 1/32" that set screws of pole-piece size would move with one complete turn.

Ray


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## ElRay (Jul 23, 2012)

bob123 said:


> WhiteWalls said:
> 
> 
> > Just out of curiosity, how would it work with a pickup that does not match the number of strings on the guitar? Like putting a 6 string pickup on a 7 string, would it have a similar effect to this (lower output but similar tone)?
> ...


To refine that a bit, your center strings would likely none to a small affect, but the outside ones would likely have a small to large amount of roll-off, because they are further outside the magnetic field. Again, it would depend on the specifics.

See above, I did just the opposite (6-strings riding between the poles of 7-string pick-ups).

Ray


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## bob123 (Jul 23, 2012)

ElRay said:


> *On-Topic:*
> I have a 7-string I am in the process of converting to a wide-neck 6-string (same spacing as a "narrow" necked Classical), and all the strings cross the pick-ups between the poll pieces. With the original Schecter 7-string pick-ups, I have not noticed a difference on strings 2-4, but I have noticed an improvement on the top and bottom strings. That's easy to chalk-up to the effective elimination of edge effects.
> 
> I think one of the big complaints about straight pick-ups in a compound scale guitar is that the bridge pick-up turns into a "Tele-style" pick-up and a lot of folks don't like the "twanginess" introduced. Likewise, a straight neck pick-up will make your treble strings sound like a middle pick-up, which many don't like mixed with the regular neck pick-up sound of the bass strings.
> ...



Guess I need to throw away my engineering degree, and quite my power plant systems engineering position where I work with power generation daily... Because this guy has more posts and has built a couple guitars. 

Im not speaking from "guitarist" vantage point, Im speaking from an engineer's standpoint. Simply because your luthier says its so, does not make it so.

I' was also a little ambiguous in my posts. I did that on purpose. There is no "one way to do it", however for the distances described for guitar purposes, there is no significant matter for misaligned pole peices!


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## wildchild (Jul 23, 2012)

I was wondering how I would align my nailbomb 7 as mine has both rows of adjustable pole pieces





notice the neck has non adjustable while the bridge has screws on both


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## ElRay (Jul 23, 2012)

bob123 said:


> Guess I need to throw away my engineering degree ...


OK. I'll throw away both of mine too  As an engineer, you should know that observations sometimes deviate from what you're expecting.


bob123 said:


> ... power engineering ...


Biological control systems and modeling. The currents & voltages I dealt with are probably as many orders of magnitude below typical guitar signals as your work is above. We can meet in the middle.

Ray


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