Lowering an acoustic action

[Dan The Man]

Hello all,

How do you go about setting up an acoustic?

I apologise if this is a stupid question however here we go. On an electric I know how you can adjust the intonation and lower the action etc, but on an acoustic, i have no idea! please could you tell me how/if you can adjust acoustic intonation and how do you lower the action - do you shave the nut? do you lower at the bridge????? Help please!!!

Cheers in advance!!

[Stuco]

Go to www.frets.com they have lots of great set up tips. The easiest way is to file down the bottom of the saddle. It is important that you know what you are doing. Read up b4 you do this. Check intonation etc. If it is an expensive guitar take it to a guitar tech.

[Rob DiStefano]

The more tweakable parameters a guitar offers, the easier it will be to setup to your playing style. The spectrum runs from a bolt-on neck solid body with fully adjustable bridge and headstock truss nut, to an early Martin acoustic with no adjustable truss rod. Tweak parameters are ...

- removable bolt on neck
- adjustable truss rod
- movable bridge
- movable saddle(s)

Most acoustics have only an adjustable truss rod. Since the truss rod is NOT there to tweak playing action (although it will alter playability), you've got basically three ways to setup a flat top acoustic for playability ...

1. change the saddle height and/or saddle shape
2. if the top is bulged behind the bridge, install a JLD Bridge Doctor
3. get a neck reset (Expensive!!!)

You can avoid number 3 by carefully checking yer acoustic's neck angle before buying it.

What can I do to make my flat top acoustic action lower?

Typically, assuming that the neck relief is acceptably low and the bridge isn't lifting and there's no top bulge behind the bridge, you tweak the saddle height in order to lower a flat top's action. First, check the neck set angle carefully - you want to see a reasonably low enuf neck angle so that the saddle is high enuf to sand down and lower the action.

You can check the neck angle by placing a straight edge on the middle of the fingerboard and notice where the straight edge's bottom corner meets the top front of the bridge - in the best of worlds, the two corners should kiss, or the straight edge corner should be ever so slightly above the bridge's front edge. This will mean that you can lower the saddle for lowest string action, and over time compensate for the inevitable top/bridge bulge that increases string action. If the straight edge's lower corner falls below the front top edge of the bridge by more than 3/32" or so, it could be a not-so-good omen for the present or future playability/action tweaks.

In addition, if there's room to sand down the saddle bottom, you may find the string angle behind the saddle is very shallow. This can be fixed by "ramping" the string pin holes with a Dremel tool and a 1/8" diameter router bit.

Adjusting the neck truss rod will also affect the string action - though the rod adjust is NOT primarily for tweaking the action, it's there to add/remove neck relief to allow string/fret clearance for large string oscillations.

If there's a top bulge behind the bridge and/or the bridge is lifting, those issues need to be addressed first - a reglue of the bridge might be needed, and possibly the installation of a JLD Bridge Doctor truss rod to pull down the bulging top.

Good luck!

[Dan The Man]

Thankyou very much guys!!