Hey guys,
Just a thought - will having a generous amount of relief in your neck negatively affect your intonation around the middle of the neck? Just thinking that this will mean the action is a bit higher at that point, so the string needs to be pressed further into the neck etc - just like how you get bad intonation with a normal high action...
Opinions, facts etc?
Cheers,
Jon
Comments
If your action is really high (as you noted), you do get intonation problems from having to stretch the string to far down to the fretboard.
Have you put a decent straight edge on the frets and tried to slide different thicknesses of paper between the straight edge and frets? This will give you a map of the relief. It's really easy to do too.
Leave the strings on and tuned to pitch! The straight edge touches (or almost touches) all or most of the frets at the same time. Put it between E and B strings for one side of the fretboard and the low E and A for the other side.
Rip off a single thickness of paper from the envelope that is commonly used package individual strings. It's really thin but if the paper sticks (a little bit) as you slide it between the fret and the ruler (one fret at a time) you have very minimal relief. Of course there are at least two frets that will support the straight edge. The string envelope paper should slide easily at the mid between the frets that are holding up the edge of the ruler. As you slide towards those frets that touch the ruler, the paper will begin to bind slightly. Typing paper is next, then business cards. If you get beyond business cards in the mid frets, your relief is out of bounds.
The whole business of putting relief in the neck is dubious to me, but I seem to be a minority of one. In any case, there is a range of opinion amongst guitar techs about how much relief is right.
My go to guitars relief range between 0 and typing paper. That isn't much difference. Of course at 0 there is no relief at all.
By using bits of paper of different thicknesses as feeler gauges, you'll get a fairly precise notion of the relief on your neck. If you adjust your truss rod (bit by bit, until you get a feel for it) you can create different amounts of relief to see what you like. Check also for a hump in the neck at the body join. Nearly every guitar will get some or a lot of that in time.
Most intonation problems are largely correctable by adjusting the bridge position (on selmacs). If you slide each foot of the bridge independently and find the best average intonation for all the strings and still aren't satisfied, you may need a better intoned bridge. If your using non GJ strings, this can also have a small impact on intonation.
Sorry to go on.
I would assume most luthiers build the guitar so the intonation is approximately correct when the guitar is setup. So, they would take into account what is the typical amount of relief and action, and make the neck and frets so that the intonation is good when the strings are under tension.
I've no idea if that's correct or not, but it would seem to make sense to me. Deviations from a typical relief could affect the intonation in the same way that action does, and for the same reasons. Having zero relief is one end of the extreme (a small amount of relief is usual in a good setup), so that could affect it negatively the same way a "generous" amount of relief could.
I'm not a luthier, and could be talking shite here.. it could be the case that luthiers build the guitar with geometrical assumptions that the neck is exactly flat and straight, and the action is 0mm. If you're going to use a straight bridge, maybe the consequences of that would totally dominate anything the relief or action might change with regards to intonation. I don't know, probably Bobolo will chip in with a 2000 page essay soon ...
www.scoredog.tv
My way of setting up my guitars is just that, I'm not in the biz. There's a lot of room for personal taste in how we want it to sound and play, but knowing what is actually there to begin with is important before doing anything.
I'm not trying to sell anyone on flat fretboards. I do my own bridges fret work and flat was easier to do when I started, and I noticed a playability and sound quality I liked. Wim is right to point out that "a small amount of relief is usual".
What I'm suggesting is just a way for you to find out easily what you've currently got.
I think generally the higher action you go the more intonation problems you will have. There are only few luthiers (Ari-Jukka Luomaranta, Bob Holo) who make compensated bridges and with these type of bridges you can have very little relief and moderately high action without intonation problems higher on the neck but with typical "straight line" bridges you will end up having horrible intonation higher on the neck especially on the b- and g-string if you have too little relief. But with these type of bridges the intonation problems aren't that bad if you have lot of relief. It's also a matter of what strings you use. Argentine 10s have the most horrible intonation ever compared to other strings with "straight line" bridges.
One easy way to measure the relief is to use capo on the 1st fret and then press the string on the 14th fret and try if you can move 10/1000"=0.010" string (the e-string on Argentine 10s for example) under the string and if it can move there without stopping on every fret you have atleast 10/1000" of relief which is what many think is normal relief. There are also other opinions. AJL uses zero relief. Jean Barault said 1mm of relief is perfect. Personally I've found that every guitar is a little bit different and needs to be fine adjusted to find the sweet spot where I feel that I have the right amount of buzzing when I hit the strings a bit harder The relief definately changes the sound!