Fret buzz past 12th fret.......

[Basscabman]

Howdo Folks...

My Jazz Bass has a lot of buzzing and dead notes from the 15th fret up to about the 19th, I like a really low action which i have the the rest of the neck but past the 12th i can't get it lower without the buzzing and dead notes.

I've checked all the frets from the 12th to the 20th with a fret level edge and have no high frets, There Is no shim under the neck in the pocket. I can raise the saddles to get rid of the buzz but that defeats the low action above the 12th.

Could the last fret be too high?

Cheers for any advice.

 

[Samuel Burns]

Try checking the neck relief and adjust accordingly.

[Basscabman]

I'll recheck, maybe I have the truss rod too tight...

[HowieBass]

More likely the truss rod isn't tight enough... it sounds to me like you might have a tad too much relief... 

[Basscabman]

Hardly any gap between strings and fretboard in the middle of the neck When clamping down at the 1st fret and 17th so the neck is flat.

[PaulWarning]

I'm no expert but I wouldn't have thought neck relief has much effect above the 12 fret, I would have thought string height is the issue if all the frets are level

[Andyjr1515]

Sounds like your neck relief is OK.  I aim for 'just perceptible movement' tapping the top and bottom string at the mid point between the 1st and the 16th - which sounds pretty much what you have described.

Holding down at the first fret, what is your 12th fret action height currently for, say, the G?

In general terms, two possibilities occur to me:

First is that there are some high spots somewhere that you haven't picked up.  But, as I gather you have already deduced, it is actually quite difficult to pick this up if it is the last fret because you can't use the 3-fret rocking method.  You actually can't do too much harm taking the last fret down a tad so this is certainly something worth considering.  If it is this, then it wouldn't take a lot - masking tape either side of the fret, then a few even strokes of a fingernail emery board along the top, then removal of the scratches with emery paper 400 through to 2000 (I think you can get a mixed pack at Halfords) would do the job.  

Second is that you are at such a low action that you need to consider a gentle and even dropaway of the upper fret heights.  If this is needed it should be done by an experienced tech or luthier because, other than the end fret, every fret will affect every other fret - so it does have to be done right! 

I'm no expert, but I gather the reason some builders incorporate a dropaway (basically angling the upper frets progressively lower - but we are talking teeny amounts) is that the geometry of the neck and fretboard changes as the heel starts deepening and the neck meets the body.  Before this, the neck is flexible and the relief curve is smooth.  But near and over the body, the neck is rigid and straight - it can't and it doesn't bend.  In most cases - because we are talking about very small measurements here - the action height is high enough that this gives no problems at all.  But if you are talking VERY low action, then these sorts of things matter a lot.

Hope this helps

[Geek99]

23 hours ago, Basscabman said:

Howdo Folks...

My Jazz Bass has a lot of buzzing and dead notes from the 15th fret up to about the 19th, I like a really low action which i have the the rest of the neck but past the 12th i can't get it lower without the buzzing and dead notes.

I've checked all the frets from the 12th to the 20th with a fret level edge and have no high frets, There Is no shim under the neck in the pocket. I can raise the saddles to get rid of the buzz but that defeats the low action above the 12th.

Could the last fret be too high?

Cheers for any advice.

 

There are usable frets above 7th ? Huh ? He’s obviously from some other freaking galaxy 

Edited November 24, 2019 by Geek99

[Geek99]

11 hours ago, HowieBass said:

More likely the truss rod isn't tight enough... it sounds to me like you might have a tad too much relief... 

Wouldn’t this cause less buzz, not more?

[PaulWarning]

maybe I misunderstood the post, I thought the problem was buzz when playing above the 12th fret, but if you've got buzz above the 12th fret while playing roundabout the middle of the neck then too much relief might course that

[Andyjr1515]

13 minutes ago, PaulWarning said:

maybe I misunderstood the post, I thought the problem was buzz when playing above the 12th fret

I've interpreted it the same way, Paul

@Basscabman ?

[Basscabman]

Steamed in to the last fret with a fret file and bosh! No buzz. One to watch out for folks. 

[Andyjr1515]

1 minute ago, Basscabman said:

Steamed in to the last fret with a fret file and bosh! No buzz. One to watch out for folks. 

Excellent!