The way a P bass should be

[DJ Bebop]

The magnetic field lines converge on the cover which is only 3/8" above the strings.

So what is it you are saying the covers are doing in the equation?

 

[Eli Brockway]

Do the covers make the magnetic field taste like carrots?

 

[Wood and Wire]

every bass has areas of the neck where there is less sustain.

On a forum where most people seem to prefer flat wounds, tape wounds, and foam / felt mutes ; that would be the whole neck.

I'm surprised it isn't a desirable feature.

 

[Slevage]

The magnetic field lines converge on the cover which is only 3/8" above the strings.

Can I see your calculations or measurements. Can you tell be how many gauss the field is at that distance? The B-H curve of the material that the cover is made of?
Without data, it can't be assumed that field are distributed by the cover.

 

[bluesblaster]

Im pretty sure if you did a blind sound test with covers and without no one would be able to tell the difference. Guitar makers like Fender were mimicking the automobile industry , even using colors right out of GM's color catalog. Chrome accents were big in the late 50's and early 60's, check out a photo of a 58 chevy Impala for reference.

 

[gln1955]

It's safe to assume that if covers made a difference in a pickup's responsiveness, bass makes and pickup makers would be exploiting that in their designs.

 

[DJ Bebop]

It's safe to assume that if covers made a difference in a pickup's responsiveness, bass makes and pickup makers would be exploiting that in their designs.

And you would have a giant aftermarket hawking different shapes and densities that purported different tone variations.

 

[Perfessor]

Can I see your calculations or measurements. Can you tell be how many gauss the field is at that distance? The B-H curve of the material that the cover is made of?
Without data, it can't be assumed that field are distributed by the cover.

850 gauss average at the poles, 400 average top of strings and 155 average at the cover.

 

[Slevage]

850 gauss average at the poles, 400 average top of strings and 155 average at the cover.

Not enough force imposed on the material of the PU cover to make any difference.

 

[micguy]

On a forum where most people seem to prefer flat wounds, tape wounds, and foam / felt mutes ; that would be the whole neck.

I'm surprised it isn't a desirable feature.

Flats kill the sustain of the higher harmonics, but the fundamental still rings out for a decent duration. Most dead spots kill the sustain of the fundamental - on a bass with flats, that makes dead spots more apparent - definitely not a good thing.

 

[andare]

Flats kill the sustain of the higher harmonics, but the fundamental still rings out for a decent duration. Most dead spots kill the sustain of the fundamental - on a bass with flats, that makes dead spots more apparent - definitely not a good thing.

Well said. The C# and D on the G string of my P bass last one second and die off immediately. It's a stark difference from the neighboring notes, which ring out for a long time even with flats and foam.

 

[Perfessor]

Not enough force imposed on the material of the PU cover to make any difference.

Thanks for your opinion, but pickups with weak gauss readings still produce sound via disturbance of the magnetic field, albeit weak as it is. The magnetic field travels along the conducting cover from all of the pickup posts; I will grant you it's a weak force, but it is a force that I find noticeable. Note I do not have any hearing loss because of I have been using ear protection for over 50 years.

 

[micguy]

The magnetic field travels along the conducting cover from all of the pickup posts;

Metal pickup covers are made from metals that aren't magnetic - your description assumes different materials. As they are conductive, they produces eddy currents when the field changes, so they do affect the sound, but not in the way you described.

 

[micguy]

It's safe to assume that if covers made a difference in a pickup's responsiveness, bass makes and pickup makers would be exploiting that in their designs.

They do, and pickup makers use specific metals to minimize/control their effects. Les Paul pickups use a rather expensive metal to minimize the effects , but still provide some electrostatic shielding. A lot of Bartolini's pickups have brass in them - you don't need brass at all to make a pickup work, but it's a good material for putting controlled eddy current damping into them. I designed phonograph pickups early in my career, and we made structures out of brass that were used in our designs for that very purpose.

 

[Perfessor]

Metal pickup covers are made from metals that aren't magnetic - your description assumes different materials. As they are conductive, they produces eddy currents when the field changes, so they do affect the sound, but not in the way you described.

Chrome plating is conductive. The covers have an effect on the magnetic field.

 

[micguy]

Chrome plating is conductive. The covers have an effect on the magnetic field.

There is a difference between electrical conductivity and being ferromagnetic - I think that's the source of your confusion. Chrome plating induces eddy currents when the field changes, but it does not affect the shape or size of the static field.

 

[Perfessor]

There is a difference between electrical conductivity and being ferromagnetic - I think that's the source of your confusion. Chrome plating induces eddy currents when the field changes, but it does not affect the shape or size of the static field.

Exactly. The cover doesn't change size of the field, but the magnetic field bounces around under the cover. It gives a more even tone and less spiking. Those with hearing loss don't hear any difference, some people, including me, do hear a difference. The covers also add mass which redistributes the G string dead spots to a point on the neck that makes most playing unaffected.

 

[micguy]

The covers also add mass which redistributes the G string dead spots to a point on the neck that makes most playing unaffected.

Yeah, we're gonna disagree on that one.

 

[Slevage]

Thanks for your opinion, but pickups with weak gauss readings still produce sound via disturbance of the magnetic field, albeit weak as it is. The magnetic field travels along the conducting cover from all of the pickup posts; I will grant you it's a weak force, but it is a force that I find noticeable. Note I do not have any hearing loss because of I have been using ear protection for over 50 years.

Since part of my daily job included measuring magnetic fields and their effect on surrounding materials, my statements are not opinions. You can verify the effect of the fields of pickups by getting the pickup too close to the string, causing a worble in the notes, then increase the distance between the pickup and the string to make the effect go away.
As others have said, if the pickup covers make a difference in sound, we'd see more covers from major manufacturers.

 

[ScoobyDoober]

So that's what a P bass is supposed to look like? I sure am glad I don't care cuz that looks awful