MIMF

I took my acoustic guitar on vacation with me last week, and am wondering if I can lower the action.

My experience to-date has been entirely with electrics, so I'm in uncharted territory here. The guitar has not had anything done to it other than having strings replaced since I got it.

Relief measures .017" (Capoed at 1st, fretted at 15th at the body, measured at 7th)
Action measures .140" @ 21st, .120" @ 15th and .075" @ 5th fret

Nut slots seem to be a good depth. Fretting between 2nd and 3rd, I'm getting less than .005" between the strings and the first fret.

I'm not sure what measurement I can reasonably shoot for as to the action. I believe that whatever reduction I want to make at the 12th fret, I can arrive at a figure a bit less than double that, take that much off the bottom of the bridge, re-tune to pitch then check again.

Any thoughts on what I can try to achieve with this, and my proposed methodology is appreciated.

I would adjust the truss rod to reduce the relief to around .004" and see what that does, could be quite dramatic. I personally prefer quite low relief since I play lightly, heavy players might want up to .008" - .009" - but .017" is way too much. Most people measure action height at the 12th fret as a reference, and I set up for 1/16" (.062") on the DGBE strings and 3/32" (.093") for the low E and A strings, or a gradual variation between the two extremes if I don't want to set each string individually.

Thanks, Brian - that relief seemed a tad much to me too, but again, I'm not used to working on acoustics. I'll take that down to .008" or .009" and see what that does for me.

Okay - reduced the relief to .009", which dropped the action at the 12th fret to .100". No buzzes appeared, so I'm thinking that I should move on to lowering the bridge a bit - maybe taking off .060" or so, then checking where I am - or would that be too aggressive?

Truss rod adjustments can be funny: sometimes after you loosen or tighten them the neck will keep moving for a little while. It's almost always a good idea to let it rest for a few days before you do anything else. Then, if it's still OK you might drop the saddle a little bit. It's usually easiest to work on the bottom of the saddle, since you can just sand it off flat.

Alan Carruth wrote:Truss rod adjustments can be funny: sometimes after you loosen or tighten them the neck will keep moving for a little while. It's almost always a good idea to let it rest for a few days before you do anything else. Then, if it's still OK you might drop the saddle a little bit.

Thanks, Alan - I'll do that. I was going to work on the bottom as the bridge is compensated, and didn't want to mess with that since the intonation is quite good, and the bridge is loose so not a problem to remove, sand a bit off, and replace.

.060" sounds quite aggressive. I would go about half that and see if you can set it up for buzz free playing. If it plays fine but then starts to buzz a little when you really dig in, then you know you have arrived.

Yeah, all the guys are leading you in the right direction.

My specs are usually like this:

Neck Relief - .0014 max. .0006 min. Depends on players style.

At the 1st fret:
Bass E - .0028 max. .0022 minimum
A - .0026 max. .0020 minimum
D - .0022 max. .0018 min.
G - .0018 max. .0014 min
B - .0016 max. .0012 min
Treb. E - .0014 max. .0010 min

Capo on 1st fret.
Height at 12th

Bass E - .0070
Treb E - .0050

The other strings simply follow the fret board curve.

Remember that when you are adjusting the bridge saddle, you have to sand off twice as much as the amount you need at the 12th fret.
I measure how much the strings need to come down, first.
Then I use my caliper to make a small scratch mark on the side/bottom of the saddle, which I then fill in with pencil to make it easier to see.
Then sand to the line.

Steve Sawyer wrote: Thanks, Alan - I'll do that. I was going to work on the bottom as the bridge is compensated, and didn't want to mess with that since the intonation is quite good, and the bridge is loose so not a problem to remove, sand a bit off, and replace.

I don't mean to nit-pick Steve and I'm sure you know what you mean but for the benefit of any less experienced folks who come along and read this at some later date, you are talking about removing material from the bottom of the saddle, not the bridge. Correct?

Gordon - thanks again for those specs

Gordon Bellerose wrote:Then I use my caliper to make a small scratch mark on the side/bottom of the saddle, which I then fill in with pencil to make it easier to see.

I'm always prowling antique shops for old machinist's tools, and just last week picked up a hermaphrodite caliper that is perfect for this kind of task:

Andy Bounsall wrote:I don't mean to nit-pick Steve and I'm sure you know what you mean but for the benefit of any less experienced folks who come along and read this at some later date, you are talking about removing material from the bottom of the saddle, not the bridge. Correct?

Ah! - yes, Andy - I mis-spoke. It's the saddle that I'll be modifying, not the bridge. Not a good thing to be sloppy in my nomenclature!!

Keep in mind that once the relief is set and the nut is correct then lowering the action without buzzing will be dependent on how level your fret plane is. The recommendation to take material off the bottom of the saddle a bit at a time is a good one.

Gordon Bellerose wrote:Yeah, all the guys are leading you in the right direction.

My specs are usually like this:

Neck Relief - .0014 max. .0006 min. Depends on players style.

At the 1st fret:
Bass E - .0028 max. .0022 minimum
A - .0026 max. .0020 minimum
D - .0022 max. .0018 min.
G - .0018 max. .0014 min
B - .0016 max. .0012 min
Treb. E - .0014 max. .0010 min

Capo on 1st fret.
Height at 12th

Bass E - .0070
Treb E - .0050

The other strings simply follow the fret board curve.

Remember that when you are adjusting the bridge saddle, you have to sand off twice as much as the amount you need at the 12th fret.
I measure how much the strings need to come down, first.
Then I use my caliper to make a small scratch mark on the side/bottom of the saddle, which I then fill in with pencil to make it easier to see.
Then sand to the line.

In the above specs, I said that the neck relief was from .014 to .0010.
Those specs would be for a BASS.

An electric guitar would be .0010 - .0004

The higher set of specs would be for an acoustic. The lower specs for an electric.
Generally an acoustic sets up just a bit higher.

Gordon - correct me if I'm missing something, but I think you have an extra zero to the right of the decimal in many of your specs. I wouldn't be able to measure .0004" of relief.

You are correct Peter. My mistake.
Those are 1000's, not 10,000's.

Gordon Bellerose wrote:You are correct Peter. My mistake.
Those are 1000's, not 10,000's.

Heh, heh - I totally missed that, even when I copied and edited these values into a setup specs doc that I'm maintaining...I see what I expect to see I guess (or my old eyes aren't as sharp as Peter's! )

Closing the loop on this thread, I followed the advice above and ended up with a much improved action. Got the action on both the low and high E strings to .065, and rather than futz with it further figured his was good enough since I haven't (yet) introduced any other issues.

Thanks all for helping me work through this!

I think your low E string might have to be raised up a bit to prevent buzzing. But if it is not buzzing, very well done.

Barry Daniels wrote:I think your low E string might have to be raised up a bit to prevent buzzing. But if it is not buzzing, very well done.

Nope no buzzing - that's why I didn't try to get the high "E" any lower as I was sure to get myself into trouble!

Steve Sawyer wrote:Okay - reduced the relief to .009", which dropped the action at the 12th fret to .100". No buzzes appeared, so I'm thinking that I should move on to lowering the bridge a bit - maybe taking off .060" or so, then checking where I am - or would that be too aggressive?

I'd try dropping the relief a bit more, maybe 0.006". You can always loosen the rod to get back to where you are now.