Why do you get a warmer Neck Pickup tone on a 22 fret guitar than a 24 fret.

sweepy

On a 22 fret guitar the pickup dit’s on the harmonic node of the string ie the 24th fret position, it’s purely down to the physics of the string vibration . If you look at a Strat neck pickup outs fret 24 and middle is 36 fret position, simple really 

TTBZ

I think I'd lose my bearings on a 24 fret guitar, I've always played 22 and have never once needed the 24th. 

thegummy

sweepy said:

On a 22 fret guitar the pickup dit’s on the harmonic node of the string ie the 24th fret position, it’s purely down to the physics of the string vibration . If you look at a Strat neck pickup outs fret 24 and middle is 36 fret position, simple really 

The harmonic node idea would only apply to open strings.

Btw, a Strat neck pickup lines up proportionally with the neck pickup on a 22 fret PRS / Les Paul. I made sure it did before I switched from both of those to a humbucker Strat as my main guitar because that tone is important to me.

GuyBoden

sweepy said:

On a 22 fret guitar the pickup dit’s on the harmonic node of the string ie the 24th fret position, it’s purely down to the physics of the string vibration . If you look at a Strat neck pickup outs fret 24 and middle is 36 fret position, simple really 

Isn't, the harmonic at the imaginary 24th fret position on a 22 fret guitar only relevant for open strings. Once you fret a note the harmonic moves.

ICBM

The harmonic node theory is nonsense because it not only applies only to open strings, harmonics are *not* present at node positions, ie it would be the exact opposite, if that was the reason.

It’s simply that the pickup is further from the bridge on 22-fret guitars and so has a different mix of harmonics which slightly emphasises some of the lower ones.

JamieWakeham

GuyBoden said:

Isn't, the harmonic at the imaginary 24th fret position on a 22 fret guitar only relevant for open strings. Once you fret a note the harmonic moves.

Just looking at the harmonic nodes and antinodes is a bit of an oversimplification.  I talk about this in A level physics (and demonstrate, which is always fun).  When you pluck a string, there are many harmonic modes it can vibrate in.  What it actually does is assign energy to all the different modes.

Most energy goes into the first harmonic (wavelength = 2L, one node above the 12th fret and no antinodes [not counting the obvious antinodes at the nut and bridge]) and that controls the note we perceive it to be playing. 

But energy also goes into the second harmonic (wavelength L, one antinode and two nodes), the third harmonic (wavelength 2L/3, two antinodes and three nodes), etc etc.

The key is that the string is playing all these notes at once.  Exactly what balance there is between all the harmonics is very hard to predict, and is a massive contributor towards the tone of the guitar.  There's a whole branch of mathematics, Fourier analysis, which is to do with breaking the extremely complex sum of all these waves back down into their individual harmonics.  Thankfully that doesn't come up on A level...

What you need to think about is which harmonics have large amplitudes above each pickup.  Most importantly, the first harmonic has max amplitude in the middle of the string and goes to zero as you approach the bridge.  So a bridge pickup sees much less energy from this harmonic, so comparatively it's getting more energy from the higher harmonics and less from the lower ones.  In comparison, the (say) 10th harmonic will have a wavelength smaller than the distance between the bridge and the bridge pickup, so that pickup still gets the full influence of that harmonic.

Regardless of where you're fretting, this pattern remains true: you'll be setting up a new string length, and the first harmonic of that length won't have much amplitude above the bridge pickup but the higher ones will.  

This also explains things like tapped and pinched harmonics - when you tap above the 12th fret you are effectively forbidding the first harmonic (as well as the third, fifth, etc) so all the energy has to go into the second, fourth, etc.  A pinched harmonic forces there to be a node very close to the bridge, so you are preventing energy from entering all the lower harmonics and the lowest allowed mode will be the 10th (or something like that).