Where is the JB's mid spike

[alex1fly]

Internet speculation abounds, and I can only find vague "mid hump" descriptions - let's get some data!

What frequencies do you all hear boosted in the JB?

[jeremy]

freefrog should be here shortly

[Chistopher]

In your head mostly

[alex1fly]

In your head mostly

Are you responsible for that voice in my head? Let's turn it down a notch please

[GuitarStv]

Between 1.6Hz and 2kHz, depending on the loading of the electronics you've hooked it up to.

[Blille]

I always thought it was 2k. Not sure where I got that from.

[Mincer]

It is the 'barky' ones. I was never good with numbers.

[Rex_Rocker]

IME, the JB also has some low mids, not just high-mids. That's why I think people often call it "loose". I don't think it's loose, personally, but it can be kinda stuffy in some scenarios. Honestly, I think it's a chunkier pickup than people give it credit for.

[Mincer]

Well, the bass of a JB isn't like on a modern metal pickup- yu don't have that chug. But it works so well with Marshalls and 5150-style hot rod Marshalls for everything just short of modern progressive metal.

[DavidRavenMoon]

Internet speculation abounds, and I can only find vague "mid hump" descriptions - let's get some data!

What frequencies do you all hear boosted in the JB?

That frequency changes depending on the load on the pickup.

But they have an upper mid hump. Maybe 4K. People mistake it for treble.


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[DavidRavenMoon]

IME, the JB also has some low mids, not just high-mids. That's why I think people often call it "loose". I don't think it's loose, personally, but it can be kinda stuffy in some scenarios. Honestly, I think it's a chunkier pickup than people give it credit for.

It’s loose because it’s a lot of wire and an alnico 5 magnet. The magnet isn’t quite strong enough to retail the transients. I call it mushy. And kind of muddy clean. Not my favorite pickup.


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[beaubrummels]

At risk of great peril of a 25 page thread derail, I will say, I have a JB Seymour wound in the late 70's and a new production JB from about 2012 or so, and they sound like different pickups. Neither of them has a 'spike' per se, but the newer one has a thick chunk of mids (which by itself is not bad, it's a great rock pickup) the problem is it doesn't have any treble, so it sounds dark, muddy, congested, all the other adjectives, and it never cleans up rolling the volume off. The one Seymour wound has some top end and is bright and even. It cleans up with rolling off the volume. It sounds a bit like a Custom with the treble rolled off. Kind of like what a WLH is to a 59, Seymour's JB is to a Custom. (And if memory serves, the old JBs use RCA5s, which could be the main difference.)

[Aceman]

2k sounds/feels about right.

The spike is a tight little bump there that is loud enough to be perceivable. PG has one too.

Kind of a little return to rising on the down side of the curve.

Looked for some pics but couldn't find one.

[freefrog]

freefrog should be here shortly

Shazam...

...Here I am!

Below is my humble attempt to share. Readers will decide if it makes sense for them or not...

Internet speculation abounds, and I can only find vague "mid hump" descriptions - let's get some data!

What frequencies do you all hear boosted in the JB?

What GuitarStv and David said, plus a couple of my indifferent thoughts and "data":

-with twice the inductance of a P.A.F. clone, a SH4 has a resonant peak located in the high mids as soon as it's played through a "normal" cable capacitance... count on a Rz around 2400hz through 3m of cable... and HALF of this value if it's played through 15m. Below is the Rz measured through a cable somewhere between these values - I think it was a 6m/ 1nF one and it still makes the Rz very mid centric.

EDIT - I've added in orange the Rz of a SH55b as captured through the same cable during the same test. The pic is a bit blurry but these screenshots were done 15 or 20 years ago, so stacking them just gives a blurry pic. Sorry for that...







-as high inductance bumps the output level whatever is the magnetic strenght at play, a SH4 also tends to promote the frequencies under or "around" this Rz, as said by Clint. Below is the response of a SH4 played in chords from unfretted strings to 12th fret...



NOTE - in both screenshots, there's a descending "stair step" a bit below 10khz. It's due to coils coupling and contributes to "focus" the response of the JB in the high mids.

Non limitative contribution, FWIW.

The lunch having ended, I go back to work now.

[PFDarkside]

I think seeing it against a 59 would be informative. All standard passive pickups have a resonant peak like that so seeing the difference compared to a PAF style would let you see the perceived “spike”.