Achieving Low Action

[dalandser]

Hello,

I have more experience tinkering, upgrading, setting up, and playing guitars than I do building them. I can get a guitar set up pretty well in terms of low-ish action and correct intonation at the 12th fret. I recently bought a used Schecter 006 Elite that was really beat up cosmetically and that had really old rusty strings with worn down frets. I tuned it up and it had the lowest action of any guitar I've ever had, including an Ernie Ball Music Man JP6 (bought new, then fret leveled), another 006 Elite that I had fret leveled, and a Made in USA Parker MaxxFly. The Ernie Ball and the Parker were disappointments in terms of how high the action ended up being after a setup. Then this Schecter with crusty rusty strings and worn frets had the lowest action of any of them. I changed the strings and unfortunately the action wasn't as good after a setup. The low E is now probably a string width higher than it was before. All this has got me thinking about what really makes a guitar capable of having low low action with no string buzz. Since I've never built a guitar or a neck, I'd like to hear what some builders have to say about this. I'm looking for honest to goodness experience in terms of finding what can really get a guitar to have nice low action. Here's my intuition, please correct me if I'm wrong.

It seems that first of all having level frets and a bridge that is the correct radius for the frets are a must. Secondly it seems that the strength and tolerances of the truss rod threading are important. For instance are there really nice truss rods that have a higher number of turns per bend similar to how nicer tuning keys have higher tuning ratios? Finally it seems that the specific arc that is created from the interaction of the truss rod and the specific neck material and dimensions will create the correct circumstances for the lowest action possible.

From a set up point of view, I had been told in the past to straighten out the neck as much as possible until low E string clamped a the first and last fret will barely vibrate or make a tapping sound when pressed against the middle most frets. I've tried this and consistently had to raise the bridge too high to get rid of string buzz. Only after giving the neck more relief have I found that I can get a moderately low string action again without buzzing strings. It's now my intuition that making really small truss rod adjustments will find the true sweet spot for each guitar during each setup to achieve the lowest possible action and that it's actually a process of trial and error rather than simply dialing some measurements and assuming it's a done deal.

I've read many posts on multiple forums about people getting 'super low' action with no string buzz. Are these statements accurate? I know that 'super low' is a subjective value and I'd say I can get about a little more than two full millimeters away from the last fret with the low E string. I wouldn't call this 'super low' especially compared to how low the action was when tuned up this most recent guitar with crusty strings and the same value was more like 1.5-1.75 mm before I threw on new strings and had to give it a full setup. I like to play moderately technical stuff higher up on the neck and this is why I really like low action, so that I'm not having to really press down on the strings and find the fret at the same time which really slows things down. I'm not obsessing over this, but since I've spent a fair amount of time setting up the guitars I play in the last few years, I'd appreciate any feedback from some people that are more experienced and knowledgable than me.

Thank you and have a great day,

Anthony

Edited August 14, 2011 by dalandser

[Linny]

Well first of all it depends if we are talking about acoustic or electric guitars. Acoustics need a higher action in general because we don't want a huge amount of buzz coming from a un-amplfied instrument. Electrics can have an acceptable amount of buzzing and still be considered buzz free when played through an amp. The term "buzz free" is a personal opinion. I worked in a guitar shop for 5 years and i must have setup thousands of guitars and even with the best playing guitar ever some customers were still unhappy if their electric guitar buzzed slightly when played unplugged. All guitars buzz depending on setup and how hard its played.

So ignoring acoustics this time.

With electrics my personal preference is to have a nearly dead straight neck and as low an action as i can get away with. Now if you have an old tele with a 7.5" radius then it isn't gonna cut the mustard as its gonna choke when you bend a string. With some guitars its nearly impossible by design to have it set-up the way i like it . You have to accept that with certain guitars.

The last guitar i finished building had a 5 piece neck, trapezoid neck profile, double action truss rod, ebony fingerboard and no radius (flat) with tall/medium width frets and it does have an incredibly low action but it still buzzes! It does buzz to an acceptable level (in my opinion) but some may feel it does a little to much but would understand when they see how low the action is and how little relief it has.

The high e at the 1st fret measures .012 (.33mm) and low E measures .020 (.5mm) and high e at the 12th is .020 (.5mm) and the low E is .040 (1.1mm)

When i decided to build the neck the way i did i knew that a 5 piece neck and ebony board with a trapezoid profile would result in a very stable, solid and straight neck. So much so that when i strung it up for the first time i had to dial in some relief with the truss rod. I also dressed the frets with a little relief at the 7th-12th fret and added some fall away to higher frets so it would buzz less lower down on the low strings.

To measure relief i use the 1st and 17th fret and look for a gap at the 3rd fret on the low E. Some use the first and last fret and look for the gap a the 7th or so. I use the 1st and 17th because all guitars have a 17th fret (the last fret could be the 20th-24th depending on the guitar) and this is the round about the point where the truss rod ends/stop working anyway. I give the string a tap with my pinky at the 3rd while holding down the string at the 1st and 17th and look for a small gap (around .33 mm) for a pretty straight neck. Once thats done i adjust the action at the bridge to a reasonable height then i look at the nut to see if it needs its slots filed. The nut needs to be at the correct height if you want any chance at setting it up properly.

This is a good book for understanding the topic Dan Erlewine

Hope that helps in someway............

[DarkAvenger]

I'm fairly new to the setup game, just a few years under my belt and mostly setting up new guitars, so correct me if I'm wrong. However, one element I think should be recognized would be the neck angle. Now, I know about why some necks need angles and some dont, but I think this is actually relevant in a different way. Depending on the material and specs of the neck, your neck is going to bend. Even with a truss rod, a more flexible neck will have more variation in where it bends and how much it bends. With a strong neck, like say a 5 piece neck with double action truss rod neck angle won't vary much. But a flexible neck(maybe with a one-way truss rod) might bend more at the bottom or at the middle, and depending on the neck, a little neck angle will get a lower action without buzz.

[Linny]

I'm fairly new to the setup game, just a few years under my belt and mostly setting up new guitars, so correct me if I'm wrong. However, one element I think should be recognized would be the neck angle. Now, I know about why some necks need angles and some dont, but I think this is actually relevant in a different way. Depending on the material and specs of the neck, your neck is going to bend. Even with a truss rod, a more flexible neck will have more variation in where it bends and how much it bends. With a strong neck, like say a 5 piece neck with double action truss rod neck angle won't vary much. But a flexible neck(maybe with a one-way truss rod) might bend more at the bottom or at the middle, and depending on the neck, a little neck angle will get a lower action without buzz.

The neck angle is just there to accommodate the bridge, set neck guitars that have the fingerboard flush with the top of the body will always need some sort of angle so u can fit a bridge and pickups under the strings. It doesn't alter anything else with regards to setting up the neck. It is easier to sort problems on bolt on necks.

If you come across an old Ibanez with a wizard neck (1 piece neck, single action rod) you can often find that its a warped over the years into a stretched out "S" shape. It tends to be high at the end of the fingerboard where it has been solidly attached and hasn't moved and lower around the 12th fret. It can happen on other guitars but because the Ibanez is so thin it tends to be worse. A few times i have had to repair this situation either by heavily dressing the upper frets or by removing the frets and planing the hump from the end, re-radiusing and re-freting. This is especially true on guitars that have a floyd rose which adds extra stress to the neck if used heavily.

[Woodenspoke]

I am never sure how action will be on a particular guitar. I repaired a broken plywood Davis flying V a month ago, a free repair for a friend. The headstock was smacked backward and a split ran 6 " down the maple neck, but the board was still flat.. After spending way too much time gluing the neck, replacing the nut and setting the neck angle (shims were missing) the action turned out super low. I spent little time cutting the nut slots as I had already exceeded the cost of a replacement guitar if I was actually charging them. Sometimes you never know what you will get. Dont think they even know how good the action really is now.. Oh well.

I have built some guitars where the action was not as good (in the past).