Humbuckers - Open Coil vs Covered - a question

[TheGreatGreen]

So I've been down the rabbit hole reading up on humbuckers lately and something I've seen are a few videos of shootouts between covered and open coil pickups. The uncovered, open coil pickups always sound brighter and more lively, and the covered version of the same pickup pretty much always sounds a bit softer and a bit more muted in the highs by several db.

I've been wondering if the covered versions of humbuckers sound darker because of some actual magnetic reason, or if it's something simpler, like maybe that covered pickups tend to have the magnet screws set lower in the pickup, or that the coils might just physically be a bit farther away from the strings due to the extra spacing of the cover material that sits over the coils.

Have any of you guys ever done any testing around this? Anybody know one way or the other? Can a covered pickup get back some detail and treble content by raising the height and/or the pole pieces a bit to compensate?

 

[Nigel]

So I've been down the rabbit hole reading up on humbuckers lately and something I've seen are a few videos of shootouts between covered and open coil pickups. The uncovered, open coil pickups always sound brighter and more lively, and the covered version of the same pickup pretty much always sounds a bit softer and a bit more muted in the highs by several db.

I've been wondering if the covered versions of humbuckers sound darker because of some actual magnetic reason, or if it's something simpler, like maybe that covered pickups tend to have the magnet screws set lower in the pickup, or that the coils might just physically be a bit farther away from the strings due to the extra spacing of the cover material that sits over the coils.

Have any of you guys ever done any testing around this? Anybody know one way or the other? Can a covered pickup get back some detail and treble content by raising the height and/or the pole pieces a bit to compensate?

Do you listen to Tool?

 

[endofall]

So I've been down the rabbit hole reading up on humbuckers lately and something I've seen are a few videos of shootouts between covered and open coil pickups. The uncovered, open coil pickups always sound brighter and more lively, and the covered version of the same pickup pretty much always sounds a bit softer and a bit more muted in the highs by several db.

I've been wondering if the covered versions of humbuckers sound darker because of some actual magnetic reason, or if it's something simpler, like maybe that covered pickups tend to have the magnet screws set lower in the pickup, or that the coils might just physically be a bit farther away from the strings due to the extra spacing of the cover material that sits over the coils.

Have any of you guys ever done any testing around this? Anybody know one way or the other? Can a covered pickup get back some detail and treble content by raising the height and/or the pole pieces a bit to compensate?

I've had covered and uncovered versions of several pickups and have added covers to uncovered pickups. I have noticed the same. It seems the open coil pickups generally have a more open, slightly brighter sound.

 

[BlueParfait]

It is a magnetic reason. I can't explain exactly how, but the cover interferes slightly with the magnet's field

 

[Music&Chaos]

I would think it is due to the metal cover dispersing out the magnetic field in a different way.

It could be surmised that since they cover the slugs, they are set back slightly further than they would be without the cover,.causing the shift - but I've noticed that raising the covered pickup higher does NOT change the top end in that same manner. Vice versa; the uncovered pickup, even with poles raised and slugs set back, will never have the top end sound the same as with the cover on.

It really is one of those extra little things to help tweak your sound in one direction or the other.

 

[lespaul6]

There is just a small cut in high end and gain.. Ive been down this road as well.. almost psychotic level of testing. I prefer them off so I can hear all the sounds of the pick on the strings, especially the low e string zing. I like the look of them on however... for a les paul it just looks better to me.

 

[SFW]

The cover effects the magnetic field. The materials that the cover is made from has an effect as well. Gold covered pickups will always sound darker, as the gold plating further interferes with the magnetic field.

 

[thegame]

I’ve removed the covers on a couple pickups and discovered more nuances than mentioned so far. The covers seem to “add” a touch more body and width to the tone and not simply just attenuate the highest frequencies. Covers on seemingly shifts the resonant peak slightly lower to my ear. Some cover materials are known to interfere with the magnetic field more than others. I’ve also read before that covers affect the eddy currents, as small as they may be in a pickup.

 

[stratjacket]

There’s a subtle difference and I think others above nailed it. I also wonder about impurities in the nickel covers but a quick search says it’s generally 99.5 to 99.9% pure.

I know it’s not the same thing, but I always think of it in terms of wall treatment where 2” panels only impact the high frequencies and 4” panels can treat lower frequencies better. So a thin nickel sheet between the slug and string impacts the highs slightly, but nothing a small tone knob tweak can’t fix.

 

[VonBonfire]

I’ve also read before that covers affect the eddy currents,

Probably why so many guys can't ever nail his tone.

 

[TheGreatGreen]

What about pickup covers with the top cut out? Anybody tried those?

I wonder if you could hear a difference between these and full open coils.

 

[VonBonfire]

What about pickup covers with the top cut out? Anybody tried those?

I wonder if you could hear a difference between these and full open coils?

I put a gold one on a Super Distortion. Sounds like a super distortion to me.

 

[thegame]

What about pickup covers with the top cut out? Anybody tried those?

I wonder if you could hear a difference between these and full open coils.

 

[TheGreatGreen]

View attachment 418692

lol. To be fair if you could get a pickup with black screws and slugs, and a black outer cover with the top cut out, it would probably stick out a lot less.

edit - something like this:

 

[thegame]

To be fair if you could get a pickup with black screws and slugs, and a black outer cover with the top cut out, it would probably stick out a lot less.

edit - something like this:

Going blackface is so 90’s. You’re cancelled.

 

[TheGreatGreen]

Yeah it's not my favorite look but the sound of open coils is what I'm after. I don't want to go for straight up open coils though because I anchor my finger on the edge of the bridge pickup and doing that on open coils feels weird. Also I'd probably ruin the little nylon ribbon they wrap around uncovered coils too. So... looking for some way around it without compromising too much on the tone.

 

[MGL AmpWorks]

The pickup cover is soldered to the baseplate which grounds it. The magnetic field of the cover attracts high end frequencies and they are sent to ground. So overall, less top end with cover.

 

[LPMojoGL]

My go-to for Gibsons:
Covered or uncovered neck with a 270pf treble cap (no resistor) on the volume pot, uncovered bridge with no treble cap. 500k pots.
The cap with no resistor retains highs with volume rolloff, without sounding unnatural or thin. Great for getting clean to mild breakup on the neck pup.
I like the slight treble rolloff when using the guitar volume on the bridge pup, for rhythm tones, with a bit more bite wide open for leads and heavy rhythms.

 

[VonBonfire]

Yeah it's not my favorite look but the sound of open coils is what I'm after. I don't want to go for straight up open coils though because I anchor my finger on the edge of the bridge pickup and doing that on open coils feels weird. Also I'd probably ruin the little nylon ribbon they wrap around uncovered coils too. So... looking for some way around it without compromising too much on the tone.

They can look good on the the right guitar imo

 

[Devin]

Closest I've came to testing this was with my buddy's old Epiphone SG - we removed the stock covers from the pickups and they 100% sounded brighter and more aggressive afterwards. It was a clear difference.