Screws vs. slugs pole pieces

[xblue]

Usually humbuckers have one row with screws and the other row with slugs pole pieces. However there are unconventional humbuckers that have:


- Both rows with screws (see attachment "double_screws")

- Both rows with slugs (see attachment "double_slugs")


How do those different pole pieces configurations AFFECT THE TONE?

[AdrianSD]

https://forum.seymourduncan.com/forum/the-pickup-lounge/328502-screw-polepieces-vs-slug-polepieces-tonal-different#post5550916

https://forum.seymourduncan.com/forum/the-pickup-lounge/265383-screw-hex-and-slug-pole-pieces-what-do-they-all-mean#post4384866

https://forum.seymourduncan.com/forum/the-pickup-lounge/335091-effect-of-pole-screw-and-slug-alloy#post5689856

https://forum.seymourduncan.com/forum/the-pickup-lounge/279198-slug-vs-screw-tonalities#post4631945

https://www.google.com/search?channel=fs&client=ubuntu&q=slugs+screws+pole+pieces+site%3Aforum.seymourduncan.com

[Clint 55]

You'll see double slug on pos pickups. It has an immediate and kind of glossy tone. It isn't bad. Double screw is pretty cool and it has different effects depending on what kind of screw is used. Double filister gives a bit more bite/grind in the neck and seems to have the reverse effect in the bridge and round it a bit. Double hex sounds more bitey and clicky in either position.

[GuitarStv]

The more adjustable polepieces, the better. I find that you can get better string balance and tweak the tone of the pickup a fair bit by playing around with them.

[Masta' C]

Actually, I think double-slug is an under-utilized configuration that is (unfortunately) associated with older, budget-oriented OEM pickups made of generally low-quality parts that largely lacked clarity.

Slugs are a great way to increase the inductance of a coil without doing things like adding extra iron slugs (i.e. DiMarzio "virtual vintage" tech) or relying on Alnico mags. Slugs add warmth and output, but, like a "rail" or "blade" pole, suffer from a lack of adjustability. Of course, this doesn't necessarily matter to a majority of players. DiMarzio's use of oversized set screws as "hex poles" in many of their early designs had a similar effect to using dual slugs, but allowed for better adjustment.

If you've ever played the black covered 490R/498T pickups from Gibson that they were using a few years back, those were actually double-slug under the covers and sounded great! Same with a lot of the Tom Anderson pickups, which are pretty darn exceptional across the board and use slug poles almost exclusively.

[freefrog]

To keep my answer relatively short, let's share below a screenshot showing the electrically induced response of screws coil and slugs coil with a typical HB, under typical load:



Interpretation of this pic: electrically, the slugs coil is brighter (because a wee bit less inductive) and louder (because its magnetic circuit is more efficient).

Now, this result has been obtained from a pickup fitted with a braided shielded coax cable. If it had a 4 conductors cable, results would differ cause the cable would alter coils coupling.

Other parameters able to change the tonal outcome are...

-the placement under the strings, obviously: the slugs coil of a bridge humbucker being closer to the neck, it sounds warmer than the screws coil because it filters harmonics differently (even it it's electrically brighter);

-the heights of the pickup, its angle under the strings, but also the setting of the screw poles: the more screw poles are prominent, the more inductance their coil will exhibit and the louder it will become - compensating its relative electrical weakness comparatively to the slugs coil;

-the materials and construction involved: if time and intellectual property weren't limiting my contribution, I'd share some comparisons between a dozen of humbuckers showing how they produce harmonics when their coils are excited by a 1khz signal... It would reveal that some pickups produce extremely assymetric harmonics while others generate almost exactly the same harmonic content from each coil... This difference appears to depend on the coils themselves, but also on the alloys used for the slugs, screws, keeper bars, baseplates, magnets (and such an harmonic difference can't be measured through a conventional resonant frequency measurement like above, BTW).

So, my own humble conclusion would be that practically (and not electrically), the tonal difference between slugs and screws coils depends on way too much parameters to be defined absolutely. YMMV.

[hamerfan]

I think the whole thing is rather confused here. Some say double slugs are 'warmer', the others say the same about screws.

It's so much more the mass of iron (and their alloy to lower extend) that brings the inductance up than the shape of the iron.
Double screws have double keeper bars. Slug can have different length. Even a bar magnet has a smaller amount of ferrous metal.

[freefrog]

Footnote to the previous answer: it goes without saying that the response characterizing one single screws coil or slugs coil should be "doubled" in any pickup exhbiting twice each kind of coil... in theory... but in real life, variations on other specs lead to the blurry tonal landsape noticed by Hamerfan.

I remember double slugs Epiphone pickups in which one row of slugs had been slotted to make them look like screws. Tonally, these double slugs HB's had only one remarkable feature: their tendency to sound dead comparatively to a good pickup properly built. :-P

[Mincer]

I was under the impression that the screws were very slightly warmer.

[Juanhanglo]

General rule of thumb:

Slugs = more bass and treble

Screws = more midrange.

Look at the full shred and the custom 5 for example. They are close to each other resistance wise. The only difference, besides wind pattern is the slugs in one coil.

The custom 5 is scooped, while the full shred is more even across the spectrum, with decreased bass.

Of course the pole type, pole screw length, and other stuff also play a factor in the final sound

[Mincer]

I have a 59/Custom Hybrid with double screws, and it certainly has more mids than a stock one.

[LLL]

sounds more bitey and clicky

WAT.

[beaubrummels]

General rule of thumb:

Slugs = more bass and treble

Screws = more midrange.

This is my experience - you can even tell just splitting to the slug and the screw coil one after the other and hear that difference.

[Clint 55]

WAT.

Yaz

[Clint 55]

Like I said earlier: if we're talking about double filister compared to standard, it rounds it out in the bridge and has the opposite effect of adding a bit of bite in the neck.