String height / action - what do you consider acceptable?

[clear]

So if I strum as hard as I would ever play, with my action at 2.25mm and it doesn't cause buzzing, then raising action to 3.0 will make it louder and lowering to 1.75 will make it less loud even if it doesn't buzz? I don't understand the physics if so

Frankly, if 1.75mm works for you then why worry?

The volume is directly proportional to the amount of energy (which means amplitude) you pluck the string. The uke's nylon strings have much less tension than an acoustic guitar's steel strings, so they need more room to vibrate (i.e. an equal amount of energy would mean a much greater amplitude than the steel strings). This is why, the uke's action must be high (much higher than an acoustic guitar) to get good dynamic range (think of true fortissmo and pianissimo).

As many have pointed out in this thread: the string height at the nut is actually more important than the action height at 12th especially for the uke because much of the time is spent in the lower frets. This is where you should check; and it's why I mentioned that you should also measure your action with the string fretted at the 1st fret. You might just discover why you have ukes that plays well and some that, as you put it, "horrible". It might not actually be simply the action height at the 12th.

All my ukes and guitars play extremely well. In fact, my guitar teacher even mentioned how easy my guitars are to play. I've gone thru the trouble of learning about setups and put in the time to personally setting them up. It isn't that difficult; but you need to know some basics (like what people in this thread are trying to tell you). Once you learn it, you might be able to make all your instruments play well too.

 

[clear]

In another thread you asked this question:

"If the string is not buzzing, in my opinion the lower the better, but i'm told advanced players who don't want to sacrifice volume want higher action. Also was told my Kamaka is sketchy in it's lowness. What is the physics behind higher strings = more volume (discounting buzzing)"

I figured it'd be better to answer it here because it's very related to the above question you have.

I think you are strumming and picking wrong, and this is why you are ok playing with very low action. You may be pushing the strings sideways rather than vertically. The correct way, there should be a more downward motion on the strings, and this requires a higher action for clearance. This will give you power in the strokes and clearance for playing/damping other strings.

 

[Fhede]

So if I strum as hard as I would ever play, with my action at 2.25mm and it doesn't cause buzzing, then raising action to 3.0 will make it louder and lowering to 1.75 will make it less loud even if it doesn't buzz? I don't understand the physics if so

What I think it happens is that although you don't perceive any buzzing, there is a "light contact" between strings and frets that affects the string vibration, limitating it... thus the vibration is not as strong as it could be, affecting volume and harmonics.

 

[ripock]

I give the uke to the tech/luthier and tell him to set it up. When the uke is returned it is acceptable. I don't know the number. My ruler says it is less than an inch. I just play it

 

[70sSanO]

After many years of setting up guitars, especially neck relief, I have become accustom to using an automotive feeler gauge to check string height.

On an 18" scale tenor I recall running the strings somewhat below .070" (~1.75mm) at one time without any buzz. It played like an electric guitar, but the tone did suffer some. That one is now about .080" (~2.00mm) tuned to Bb with heavier strings. It seems to be the sweet spot for tone, volume, and playability for that particular ukulele.

Which does bring up the cat-n-mouse between string height and string diameter (tension). It "can" be tough to find that balance between the best sound while maintaining a preferred playability. What is most elusive is the changing sound preference of the one playing the ukulele.

But by-and-large my tenors are setup around .085" (~2.125mm), concerts around .090" (~2.25mm) and my soprano at .100" (2.50mm).

As others have noted, you must set the string height at the nut first before messing with the saddle.

John

 

[Farkvam]

The Ukulele Review podcast has a very long but very informative video on string action:

Thanks for posting this, man0a, I enjoyed this podcast discussion.

 

[Wiggy]

Adding to 70SanO comment above:

I learned the hard way (more than once) by attempting to lower the "action" by sanding down the saddle and then filing down nut slots. Ehh! Game over. String buzzes all over the place.

I'm no expert but I think this is what happened:

If you lower the saddle, the clearance at the 1st fret is also slightly reduced. Then, if you adjust the nut by checking each string while fretting (holding down) at the 3rd to check clearance and decide to lower it, you have just lowered the string at both ends.

Nut ^v |""""""""""""""""""""""""""""""""""""""""""""] ^v saddle end

If you are not careful, this can be fatal. Yes, you can start over with a new nut and saddle but I find quite difficult to find direct replacements (width, thickness, and height) for either part. And I am not a machinist.

Since then I (only) adjust the nut slots for clearance at the 1st fret and have not touched a saddle since.

<edit> John Colter certainly knows a lot more than I about rebuilding ukes: Adjust the saddle first, then the nut.
See reply #11

Why does lowering string action (without buzzing) cause decreased volume?

If the string is not buzzing, in my opinion the lower the better, but i'm told advanced players who don't want to sacrifice volume want higher action. Also was told my Kamaka is sketchy in it's lowness. What is the physics behind higher strings = more volume (discounting buzzing)

forum.ukuleleunderground.com

 

[Jerryc41]

I've only been playing uke < 3 months but all of the ukes I own have a certain action which I consider good, and one uke which I say is horrible. I'm told the horrible height is standard (2.5mm at 12 on 4th string). Am I too picky? Did I just luck out that all my other ukes happen to be under the standard? My $150 and my $1000 uke seem to be close to 2mm. I'm used to <2.5mm on quality full scale steel string acoustic guitar, so 2.5mm on a small scale thing like a uke seems high.
This is what I measure at the 12th fret, 4th string. All are unmodified stock. Sorry to offend
View attachment 147826

I usually hear that 2 - 3mm is a good height. I'm not too particular, but I'd rather have it too high than too low. It's easier to lower than to raise a string.

You have nice pictures of them.

 

[merlin666]

I have one of these gauges but never bothered to use it on ukes. Today I measured one of my guitars that has growing action and as I had it out and was humidifying my instruments I checked out the ukes. All three measured ukes were set up by my luthier (who sadly is retiring in May) years ago. The two tenors with neck join at 14th fret had about 2 to 2.25 mm at 12th fret which I find very comfortable. However, the KoAloha concert that has a neck join at 12th fret has action of 2.5mm. This interesting because it was set up by same luthier when I initially received it but it was uncomfortable to play and I felt that it was not living up to its potential. So I had a another luthier friend cut a new saddle to raise the action and now it is much better. So I wonder if shorter scale ukes with neck joins at 12th fret generally benefit from slightly higher action (as string tension may be lower), or if this just may work well for my specific uke?

BTW the guitar (long scale jumbo with medium gauge strings) of concern came in at 2.75mm which is still fine to play, but I will bring it to luthier anyway as this is his last week of accepting instruments.

 

[kissing]

Generally speaking I'd be very happy with something 1.75mm at 12th fret as someone who prefers lower action in general.

It is important to consider that numbers don't tell the whole story.
I've found that a 2mm action on one ukulele would feel awfully high while it feels completely fine on other.
This is because they have different necks, different nuts, different frets and overall instrument is shaped differently and project a different kind of sound. What strings you use is also a factor.

Whenever I get a new ukulele, the first thing to do is go by "feel".
I play my usual things on the ukulele and can immediately tell if it feels right or not.
I would then measure the action, and usually unsurprised if it's around 2.0mm because that's my comfort zone.

Higher than 2.0mm starts feeling a bit on the high side for me personally, but this is completely personal preference.
To some people, 2.0 is too low and they prefer 2.5-3.0mm.

Also, different ukuleles have different tolerances. Some simply cannot go lower before they start buzzing and feeling funny, whereas some can.
With action too low, you also make some compromises (less lively, less volume and projection).

 

[Kekio]

New surfer in this beach here.

My wife recently gave me a brand new Kala KA-S Uke, which I loved from the very moment I opened the cardboard box it came in.

Learned and explored it far enough to be writing my first Uke song, although I'm ashamed to say I did defile it by sanding down the nubone saddle to lower the string height to 3 mm, as it was even higher than that. Maybe my little friend's neck is defectively too bowed?

Or is it usual to have really high action in entry level Ukes?

 

[man0a]

New surfer in this beach here.

My wife recently gave me a brand new Kala KA-S Uke, which I loved from the very moment I opened the cardboard box it came in.

Learned and explored it far enough to be writing my first Uke song, although I'm ashamed to say I did defile it by sanding down the nubone saddle to lower the string height to 3 mm, as it was even higher than that. Maybe my little friend's neck is defectively too bowed?

Or is it usual to have really high action in entry level Ukes?

I do not consider 3mm to be "really high". You should be able to detect a defective neck by visual inspection or by using a ruler or straight edge tool.

 

[Oldscruggsfan]

I agree that 3mm should be playable, and is no immediate cause for concern. Action for my DIY soprano is almost 4mm even after sanding as much as possible off the base of the bison bone saddle. Based on guidance from a far more experienced UU member, I was able to confirm that the reason for such high action is an improper angle at the neck joint which causes concavity along the plane between the underside of the fingerboard and the bridge. Obviously, that plane should be perfectly flat or very nearly so.

I placed an 18-inch metal straight edge on the soundboard next to the bass side of the bridge and along the bass edge of the fingerboard. Voila! Where the straight edge passes the nut, the vertical distance from the bottom edge of the fingerboard to bottom of the straight edge is nearly 2mm.

Even with such a flaw, my soprano uke (Yowling Tom) remains playable.

 

[Kekio]

Since I'll be using mine mainly for rhythm, I don't think this will be an issue at all anyway. After the bridge setup I gave it, it now plays very nicely

 

[UkingViking]

My aNueNue AMM3 came with close to 3.5 mm action. Not that I can measure tenth of a mm perfectly. That was too high.

My Cocobolo came with 2.5 mm at the 12th fret, or they claim they come that way.
It is probably the most smooth playing ukuele I have played, tied with my MyaMoe. So I would say that 2.5 mm is good for me.
Not more than 3 mm please.