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I’m wondering what you all think is the optimal saddle height for a classical guitar. The measurement I am talking about is the height of the saddle from the bridge where the saddle exits the slot to the top of the saddle, easiest measured when strings are on, top of wood to bottom of string. The one I just built is on the high side of 3/16in and I am thinking it’s a bit too tall. The string break angle looks pretty steep. I don’t know what got into me with this guitar. I thought I had all my measurements out and I should know better really but such is the way of it. All my other classical guitars hover about 1/8th which in and of itself is a bit on the high side but I like that so that in the future the action can be adjusted.

I set all my classical guitars to what I call a concert action, 5/32nds over the 6th string and 4/32nds over the first string. Almost all the customers I’ve had complain that this is to high, however all the ‘real’ players I’ve had try them like it. No buzz and powerful loud tone comes with the high action. But many people would rather have light action and play softer so I wanted to shoot for a lower action on this guitar, 4/32 -> 3/32. I got that action just fine, and it’s not too bad with the buzzing, but the saddle is sticking out 3/16th so if I wanted to bring it up to 5/32nds over the 6th string then surely the saddle height would be way too high.

Fortunately I used a bolt on method for this guitar and I am thinking maybe I should reset the neck on my 3 day old guitar

What do you think?

It sounds a little tall to me, but it might be OK if your slot is deep enough to support it, and the front of the bridge is nice and strong. I would only be worried about splitting the bridge, and maybe too steep of a break angle, but if you are using a standard tie block, that probably wouldn't be a problem.

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Waddy

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Sound Clips of most of my guitars

That does sound like quite a bit of saddle projection - though I 'think' in mm for stuff like that.
I'd wait for a few weeks (with good humidity control) and see how the guitar 'settles in' before I'd do anything very major (like neck reset) on that guitar.
I find I have to re-tune quite often, just to keep the guitar up to pitch with new strings. Things may change - 3 days is 'early on'.
Cheers
John

I make mine 2mm above the saddle block.
I use 12 & 18 hole bridges so to get a great breakover angle.
I make the saddle slot 4mm deep x 3mm wide for compensation.
You've been given some good advise in the other posts.
Wait to see if you get top & neck lift.

Mike

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Mike Collins

What seems to count in terms of sound is the height of the strings above the top. Some folks I respect suggest that 11mm is about the right height there. That works pretty well, as far as I can tell.

Break angle in itself doesn't seem to have much of an effect on sound.

Break angle is very important as the guitar ages and the action needs to be lowered.
It may have NO affect on tone -but it may on loudness!
More torque to the top-brace accordingly!
I've had way too many classicals in my shop over the years that had no angle left to the saddle .
The forward neck tilt seems to help this condition.
I just think it's very important to make my guitars so that down the road they can be adjusted easily for string height.

Mike

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Mike Collins

Question - So if 11mm is somewhat optimal, then what is the lie of the fretboard (ie ruler on frets) above the soundboard at the bridge in that case ????

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Depends on the thickness of the fingerboard and the taper, if it's tapered, and whether or not it's tapered differently on the bass side than the treble side. It also depends on the doming of the top and the style of construction you used - flat wings or dropped wings in the lower bout. However, to get your 4mm lift on the bass side and 3mm on the treble side, you need to have a height somewhere in the 2 - 4mm range off the top at the bridge. 2 to 3 would probably be better if you are shooting at 11 mm string height at the bridge. I suggest drawing a picture, using real numbers, based on your style of construction and your neck angle, and top doming. Height of bridge with an 11 mm height should be somewhere in the 8.5 mm range with 4 to 5 mm deep slot and 2.5 to 3 mm of saddle above the lip.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Re-setting an over- set neck will require moving the saddle back or adding something onto the heal.
I think planing the fingerboard might be a better alternative.

Thanks for your reply's. I think I will just wait it out a bit. The intonation is as perfect as I have ever gotten on a classical guitar so yeah maybe a reset would not be the best idea though I only need a very subtle change and might be able to make up the difference by shaping the saddle back. If it comes down to it then I'll give it some thought. The slot right now is as deep as is the projection and actually the front of the bridge is a little bit more sturdy then I usually make it too since I did a compensated saddle this time.

So I'll just wait and see. I am pleased with the tone of the instrument but not at all with the projection. I have smaller classical guitars that are a lot louder then this one.

I don't think that's an uncommon phenomenon. As Al Carruth has posted many times, "It's easier to make a loud small guitar than a loud big guitar."

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Waddy, I believe it. Though intuitively it seems the opposite. The larger body would probably tend more towards the bass side too I would think. I am really beginning to like the tone of this guitar I just wish the volume was up a notch or two. I lessened the back arch on this one to and of course I am no left wondering what that has done to the town. It almost feels as though the punch of the notes gets lost inside the body of the guitar but the trade off for volume is a good tone.

I think I'll just let her be. Play it in then let her sit around till the right person finds her.

Mike Collins wrote:
"Break angle is very important as the guitar ages and the action needs to be lowered.
It may have NO affect on tone -but it may on loudness! "

Not by itself, that I can see.

The problem here, and the thing I'm trying to settle, is that, in most cases, when people make a change that gives them more break angle they also end up increasing the string height off the top. THAT'S what seems to do the work, according the the data I've got. So, when you get in a guitar that doesn't have enough break angle to sound good, how do you fix it?

I think some folks are drilling extra holes to convert classicals from 6-hole bridges to 12-hole (and 18?); the idea being that eliminating the 'loop' around the string increases the break angle ?

How you would arrange a blind test (or instrumentation approach) to find out whether it actually makes a difference in tone/volume is another question.
With such visible changes, the 'pyschological' part of psychoacoustics really comes into play, I think.

Cheers
John

John Abercrombie wrote:
"How you would arrange a blind test (or instrumentation approach) to find out whether it actually makes a difference in tone/volume is another question."

It's a tough one, to be sure.

What I did in my experiment was to modify the bridge on one of my 'test mules' to an 18-hole configuration. This allows me to tie the strings in two different ways:
1) over the saddle and through the center hole on the front of the tieblock, or,
2) over the saddle and over the _back_ of the tieblock, and then through the center hole.
The 'standard' configuration gives a 25 degree break angle, while the over-the-tieblock tie gives 6 degrees for the 'standard' saddle height. I also made up a very tall saddle, that gives a 25 degree break angle with the string going over the back of the tieblock, and tested that too.

I made up a solenoid-operated 'plucker' that pulls the string upward (away from the guitar top) until a length of fine magnet wire breaks to release it. This gives a very repeatable pluck: same place, same direction and same force every time within close limits. I hung the guitar in a 'semi-anechoic closet', and recorded plucks on each open string using a mic in a standard position.

In one part of the experiment, I used those plucks to make up a 'synthetic strum': putting together a full set for each different condition of string height/break angle that I'm testing. I've been playing these strums in random pairs through headphones for hapless test subjects, and asking them if the two strums they hear sound the same or different. Fortunately for me, one of my students does statistical analysis for a living, and foolishly volonteered to help with this. We've got about enough data now to be able to say something useful, I think.

In terms of all the stuff you'd _like_ to know, this is a pretty small baby step. However, it illustrates some of the difficulties of finding out what's really happening with these darn boxes.

Very cool; very clever!
Thanks for the details!
If you don't see a change with such a big difference in break angles, that will pretty well 'put to bed' one thing to worry about!

BTW, how many hours are in your days there, Alan? It's amazing all the stuff you seem to do!


Cheers
John

John Abercrombie asked:
"BTW, how many hours are in your days there, Alan? "

Not enough....

It happens that recessions are the researcher's friend: when you have no orders in hand, and some stock piled up, it's easier to take a little time off to play around. Now that things are back on track a bit (HOORAY!!!) I have to spend more of my time doing trying to turn busy into money.

I wonder if the fit of the saddle in the slot would be more crucial as the saddle approached a bisecting angle. Some of the forward force serves to pin the saddle against the front edge of the slot. I have noticed that even a perfect piston fit often shows a tiny crack of light behind the saddle when brought up to pitch for a while. I wonder if there is any importance to this kind of pre-loading of the tork arm acting on the top. kind of like a cap iron on a bench plane making it stiffer. In other words, if the saddle was neutral in the slot, would there be more losses in the connection as it flopped back and forth?

Maybe the daylight you're seeing behind the saddle when it's been in for a while is caused by distortion of the slot due to the forward pressure?

I assume you are thinking that the saddle would 'flop around' under the tension change force as the string vibrates. I supose that's possible. I note that I don't use a 'perfect' bisector, so there is some force of the saddle against the front of the slot. So long as that is enough to keep the two in touch through the whole cycle, I think all of the force would be transmitted. This is mnot a major part of the sound, but it's something, and you would not want to lose it, I'd think. That might be a hard thing to track down one way or the other, but it's an interesting thought. Thanks.

Thanks Alan,
yes, I was wondering about the tension change vibration. Leaning the saddle back more like a violin bridge is such an obvious solution to the distorting forward force on a bridge it seems strange that it would not have evolved that way some time ago. I was trying to imagine some reason the vertical saddle slot may have persisted, (not that bad ideas can’t have staying power).

David, for one reason possibly, it's a lot easier to rout a vertical slot

This has really got me to thinking though. I just wish I had the time to be a researcher. When I did have the time my research experiments often resulted retops or just garbage

The angled slot is indeed an interesting idea. Perhaps the best angle would be 1/2 the string break angle.

Despite "measuring twice", one of my classicals 10 years ago ended up with a high saddle. It played OK and all, but it bugged me visually so I pulled the frets and planed the fingerboard to allow a lower saddle. I love a guitar that doesn't bug me.

The reason for using the 9 degree angle on steel strings is the 'auto-compensation' feature: as you raise and lower the saddle to change the action, the compensation stays pretty much correct. It has been pointed out that, since Classicals need less compensation, they also need less of a back angle, with five degrees being suggested. Sounds good to me.