5-string P pickups with mismatched coils and hum cancelling

[Riff Ranger]

The handoff between the two coils in a split hum canceller is an area where geometry matters. One thing that a P pickup does much better than a split J pickup (on a 4 string) is avoiding the "magnetic valley" - if you bend your D string towards your A string on a 4 string J with split pickups, when the D string gets halfway to the A 's position, the volume will drop off a lot. The magnetic field on a split J has field lines that run "sideways" in that area - the thing just can't give you output from a string in that location. The stagger of the pickup halves on a P mitigates this a lot - you can go looking for a magnetic valley, and you won't find much evidence of it. The stagger in that second dimension helps a lot

With a 5 string, that valley has to be offset - you can't run that down the centerline of the instrument, because the A string is located there. How offset should it be? Half of the distance between strings. Ahhhh - there's the rub. Some 5'er have 19 mm spacing (at the bridge, calculations have to be done for where the pickups are, which ends up being a smaller distance), some have 18, or 17, or 16 (mine are 17.5). As a result, the pickup needs to be designed specifically for your string spacing. If it isn't (I've had this issue), the magnetic valley is much more of an issue - you can have a weak string even without bending it.

So, there can be issues in the handoff between pickup halves - what some here are calling "crosstalk" (where both halves of the pickup hear a string, and you get a different tonality to that string), and you can also have a "magnetic valley", where the string gets lost in the transition.

Why do I like sidewinder pickups (Nordstrand Zenblades) or stacks (Seymour Duncan makes some J shaped stacks that are quite good)? Because they don't have imbalance issues, they don't have crosstalk or magnetic valley problems, they don't hum, and they sound like single coils.

Ooh, I'm glad you finally got to say "magnetic valley;" I bet that's what you wanted to say instead of "crosstalk" earlier So to keep the A out of the magnetic valley (I will use this term every chance I get!), you need the right pickup in exactly the right position and angled perfectly? That sure seems to be the case with this Jackson. For all its good qualities, it arrived (brand new out of the box) unplayable, with the strings against the frets and the split pickup halves flat on the P. I expect to tweak a setup and can do a decent job of it, but this instrument apparently requires an exacting setup, so I had my work cut out for me.

For all the trouble I have had getting the sound I want and proper intonation from my Squier VMPV (though I stumbled into a likely solution to the intonation issue congratulating somebody on their new bass yesterday—it was a productive day for me here ), I never ran into output issues on the A. Every pickup I have tried in that one has had pole pieces rather than blades, FWIW, though I don't see why that would matter vis a vis the valley magnetic

Is this magnetic valley conundrum common to all split-coil five-string pickups?

 

[micguy]

Ooh, I'm glad you finally got to say "magnetic valley;" I bet that's what you wanted to say instead of "crosstalk" earlier So to keep the A out of the magnetic valley (I will use this term every chance I get!), you need the right pickup in exactly the right position and angled perfectly? That sure seems to be the case with this Jackson.

For all the trouble I have had getting the sound I want and proper intonation from my Squier VMPV (though I stumbled into a likely solution to the intonation issue congratulating somebody on their new bass yesterday—it was a productive day for me here ), I never ran into output issues on the A. Every pickup I have tried in that one has had pole pieces rather than blades, FWIW, though I don't see why that would matter vis a vis the valley magnetic

Is this magnetic valley conundrum common to all split-coil five-string pickups?

The magnetic valley is a "feature" of all inline split coil hum cancelling pickups - 4, 5, or 6 string. Staggered coil pickups (like on P's) seem to avoid this via the staggered geometry - they can have the "opposite" problem (if the halves overlap in coverage to where a string gets heard by both halves) This is what people are calling "crosstalk" - there the string in the middle isn't weaker, it just sounds different than the other strings.

 

[sunbeast]

Ooh, I'm glad you finally got to say "magnetic valley;" I bet that's what you wanted to say instead of "crosstalk" earlier So to keep the A out of the magnetic valley (I will use this term every chance I get!), you need the right pickup in exactly the right position and angled perfectly? That sure seems to be the case with this Jackson.

For all the trouble I have had getting the sound I want and proper intonation from my Squier VMPV (though I stumbled into a likely solution to the intonation issue congratulating somebody on their new bass yesterday—it was a productive day for me here ), I never ran into output issues on the A. Every pickup I have tried in that one has had pole pieces rather than blades, FWIW, though I don't see why that would matter vis a vis the valley magnetic

Is this magnetic valley conundrum common to all split-coil five-string pickups?

Again we come back to the two (actually three) different ways of constructing a 5-string P, and how each potentially has a trade-off. The Squier has the short-long coils and is built so that the A string actually goes over the intended part of the pickup and doesn't interact with the other coil at all- this is an example of the same design in JimmyM's original post as also used in Yamaha P5s and can't be completely hum-cancelling without unbalancing the coils somehow (different magnets, wire and/or winding density in each coil).

The EMG method (also see Aguilar posted earlier in this thread and Nordstrand options) use two identical coils but with different sized magnets. If your A string was aligned with the way the pickup was designed then there wouldn't be any valley that it would threaten to enter without bending the string quite far (possibly physically impossible), but as it is your A string is not perfectly aligned through the center of the two coils where intended so it is instead sitting in that valley naturally. If you reverse the two halves of the pickup (put the long magnet on the bottom half) it should improve given your particular string alignment. Refer to the EMG literature to see a visual of the magnets inside your pickups.

The third P5 option is to use a standard 4 or 6 string pickup with two equal sized coils and no offset magnets, and this design will have an area of crosstalk in the center unless you route the body in a way that the pickup is not directly centered under the A string. I had a couple cheap bass builds I picked up in a pawn shop years ago that used 4-string EMG PJ pickups in a 5-string bass and they both had dull-sounding A strings

 

[Riff Ranger]

The magnetic valley is a "feature" of all inline split coil hum cancelling pickups - 4, 5, or 6 string. Staggered coil pickups (like on P's) seem to avoid this via the staggered geometry - they can have the "opposite" problem (if the halves overlap in coverage to where a string gets heard by both halves) This is what people are calling "crosstalk" - there the string in the middle isn't weaker, it just sounds different than the other strings.

Okay, I think I've got it. The A sounded noticeably different, and I might have interpreted that as lower output due to the way I have things EQed. It lacked "oomph"—right up until it didn't!

 

[Riff Ranger]

My bad analogy was the SVT being the "passive pickup" and pushed 800RB being the "active EMG run at 9V", both sort of copping a slightly compressed and harmonically-rich tone in different ways haha

I liked your analogy I just wanted to make sure I understood it correctly.

 

[Riff Ranger]

I tried to explain my theory earlier, but perhaps you missed it. If you look at the booklet included with the P5 (or PDF on the EMG site), they show the magnet location for the pickup with the long magnet on the BEA and short on the DG and I think with the assumption that your A string will run basically down the centerline of the pair of coils where it would then only be running over the long magnet. In your picture you can see that your A string is instead running near the bottom edge of the BEA coil and far more into the DG coil, so it appears it would be sitting near the edge of both magnets. I think in your case putting the long magnet on the DG side of the split might be the best course of action (this is also what I needed to do on my 4 to 5 conversion PJ to get the best alignment for the center string).

No, for once I seem to have understood after all, and that was the first thing I tried several months ago when I couldn't get that A sounding right after what seemed like a decent setup (which it absolutely needed—even brand new out of the box, it was literally unplayable, with the strings down on the frets). It arrived with BEA on one coil and DG on the other. I saw the same thing you did—that the treble side of the pickup appears better positioned to pick up the A—so I switched it to BE on the bass side and ADG on the treble side. This improved things but didn't eliminate the issue entirely. That's when I tried the P6X—yes, a six-string pickup, after running the idea past an awesomely helpful person at EMG—and still had what at least sounded like the same issue, which I think we're calling "crosstalk" for purposes of this discussion. Despairing, I recently prepared the instrument for sale, installing the stock P5 in the stock configuration (BEA/DG) and taking another pass at the setup; it finally sounded good enough that I at least felt okay selling it to someone! In the course of this discussion, I decided to try lowering the DG side just a teensy bit more, and BAM! the A now sounds like the rest of the strings. I'm wondering if I was hearing "crosstalk" right up until that final adjustment; it sounded like all the burly frequencies were canceled out, leaving only the thin ones; I probably perceived that as lower overall output.

I suspect, as do you, that the pickup would work (possibly better) with a BE/ADG split, but I took many passes at the setup when I had it configured that way and never eliminated the issue. Now that I have it working properly, though, I'm not touching anything

Much as I want one of those Yamahas that apparently nail it right out of the box, at least I don't mind keeping the Jackson if it doesn't sell; and if it does sell, I can rest assured that I haven't passed along a problem. It's a good bass

 

[BlueTalon]

One thing that a P pickup does much better than a split J pickup (on a 4 string) is avoiding the "magnetic valley" - if you bend your D string towards your A string on a 4 string J with split pickups, when the D string gets halfway to the A 's position, the volume will drop off a lot. The magnetic field on a split J has field lines that run "sideways" in that area - the thing just can't give you output from a string in that location.

I have not had the experience of bended D volume dropping off "a lot." In fact, I have experienced no noticeable volume drop-off at all. Part of that may be the superior design of the Fender Super 55 pickups I use...

I know, I know, the design of split-coil J pickups is pretty common, with not a lot of room for variation. And I don't doubt the reality of the magnetic valley. But like other things I don't doubt the reality of, like eddy currents and magnetic pull on strings, it has no real-world impact on me if I can't even notice it.

 

[sunbeast]

I have not had the experience of bended D volume dropping off "a lot." In fact, I have experienced no noticeable volume drop-off at all. Part of that may be the superior design of the Fender Super 55 pickups I use...

I know, I know, the design of split-coil J pickups is pretty common, with not a lot of room for variation. And I don't doubt the reality of the magnetic valley. But like other things I don't doubt the reality of, like eddy currents and magnetic pull on strings, it has no real-world impact on me if I can't even notice it.

Read reviews of the Stratocaster version of the Super 55 pickups to see an opposing view! On a guitar pickup with the tighter string-spacing the middle two strings are close enough to this valley to have made that design a total blunder in a guitar pickup (there's a reason there are so few split-coil guitar pickups out there among the tons of humcancelling options). I use split-coils in 4-string basses often, and the valley there is far enough so as to never really be an issue unless your pickups are way out of alignment with your bridge/neck. With 5-string split-coils the particular string-spacing and alignment start to make a bigger impact (putting a 19mm spaced pickup on a 17mm spaced 5-string bass for example could well put one of the strings into that valley on the perimeter of one of the magnets or even right between them as the useable sensing width of a coil in a J split-coil doesn't go right up to the edge of the coil in the middle). Most of the time manufacturers get it right with the instruments straight outta the factory, but it's us modders that have to be careful!

 

[micguy]

I have not had the experience of bended D volume dropping off "a lot." In fact, I have experienced no noticeable volume drop-off at all. Part of that may be the superior design of the Fender Super 55 pickups I use...

I know, I know, the design of split-coil J pickups is pretty common, with not a lot of room for variation. And I don't doubt the reality of the magnetic valley. But like other things I don't doubt the reality of, like eddy currents and magnetic pull on strings, it has no real-world impact on me if I can't even notice it.

You have to bend a note pretty high on the fretboard to get it to where it's obvious - as I said before, most folks won't notice it on a 4 string. I've had 4's with split pickups that worked just fine for me. On a 5 string properly done, it's similar, but....on 5 strings, as the valley is off center, and string spacing isn't the same on all basses, it can become much more of an issue - the geometry matters

 

[Riff Ranger]

Of possible interest to most, but particularly @sunbeast: I had an opportunity to pick up an EMG PX inexpensively, which I then mixed and matched with the P6X I had previously tried in this instrument, making what are essentially two P5X pickups. I felt brave so I undid the touchy setup I had finally gotten right and tried the long coil on the treble side to start. The A sounded about the same but the B had even bigger issues in that configuration: the attack dropped out with upstrokes or fingerstrokes, with the notes swelling as (I assume) the string came back into the area where the pickup sensed it most effectively. When I moved the long coil over to the bass side (which is how the stock P5 originally arrived) I was able to get it back to where the strings had even output without too much trouble

FWIW the PX5 seems more to my taste than the stock P5, but I don't think it makes a huge difference, and I would even give the edge to the P5 in some areas. They both sound good, but I don't think either sound will become a "go-to" sound for me.

In any event, I will have at least two EMG Ps of some sort for sale soon

 

[JimmyM]

BTW, I got that Duncan pickup, and it's dead quiet, so I'm of the opinion that it was more a distinction without a practical difference to have the mismatched coils. They did shield the heck out of it, though...big pieces of shielding tape on the bottoms of each coil.

 

[eastcoasteddie]

Who actually does that? Do you know of any companies that do split-coil 5-string J pickups sets 3-2/2-3?

Nordstrand for one. I asked that question specifically. Bartolini does that with some 5 string pickups as well - I've had some of their 5 string soapbar "J's" and "P's" that were made that way - it shows the arrangement on their web site as well. There are probably others.

Oops - sorry. Bartolini keeps theirs 2/3 (the A string is always in the same coil with the G and D), but does reverse wound reverse polarity when you look at the "2" or "3" coil going from neck to bridge, so the combination of 2 pickups is completely hum cancelling - on J's and Soapbars with in line coils. A slightly different way of getting the same result.

I have a set of Duncan Apollo J 5's, and it seems they keep both at 2/3 with the E & A on the short coil.

These pickups are extremely silent, as silent as any standard humbucker. If there is any noise coming out of them, it is imperceptible to my ears. There is more noise doming out of the amp than from these pickups.

I also noticed, according to their cut-sheet, Aguilar DCB J's are the same (assuming orientation is correct with The Bridge pickup on the left and Neck pickup on the right, for a right-handed bass…)
https://www.aguilaramp.com/wp-content/uploads/aguilar-pickup-DCB-5J.pdf

I would guess that their AG5J-HC is set up this was as well.