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  #16  
Old 05-20-2017, 11:13 PM
mercy mercy is offline
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Maybe Im not getting it or Im not communicating well. So you figure where the bridge is supposed to be on the actual top for the scale you have planned. You have decided to use a 1/8 or 3/32" saddle. You figure the comp needed for the E and e string. You rout that in the bridge. Some builders/brands just file the b string back from the break point on the middle of the saddle. Other builders/brands have multi filing points for comping each string.
What if you didnt do that filing. You just figure where the bridge is supposed to be and the angle for the E string and e string, route that as above. Then move the bridge back another 1/32. Wouldnt that eliminate the need for filing all those different break points?
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  #17  
Old 05-21-2017, 12:18 AM
Halcyon/Tinker Halcyon/Tinker is offline
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No.

If I'm understanding you, you think that there could be a setup where with the correct angle and correct location of the bridge, the contact point of the string on the saddle could all be at the leading edge of the saddle. Or middle, or back, but all on the same point of the saddle.

Whereas the actual string lengths need to be staggered, it is not a straight line.

Look as split saddle bridges. That pattern needs to happen within the available space of any given saddle slot.

In other words, no matter what you do, proper intonation requires a staggered set of contact points, they are not aligned in a straight line.

Maybe that makes sense, the day has been long and wearying.
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  #18  
Old 05-21-2017, 06:02 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by mercy View Post
Wouldnt that eliminate the need for filing all those different break points?
No. You aren't understanding what is being compensated.

Simply put, the position of the frets is calculated based on an assumption that the string vibrate in an "ideal" way. The strings don't. As a result, when fretted, the strings will sound sharp. The amount by which they sound sharp depends on a number of factors, some of which depend on the characteristics of the string itself. With each of the six strings being different from the others, those characteristics change from one string to the next, with the result that the amount by which each string plays sharp also differs. To play in tune as best as it can, each string needs its length altered by its own amount. How much each string needs is a independent of the others. There is no linear (straight-line) relationship.

The thick E string requires more lengthening than the thin e string. If one draws a straight line between those two points, the amount of compensation is correct for those two strings only. The position that gives the best intonation for the other four strings does not lie on that connecting straight line. There is no reason that it should.

For many years, many manufacturers made straight, angled saddles with the string breaking point along the center of the saddle. Doing so results in fairly poor intonation. More modern manufacturers get one step closer by having the breaking point for the B string as far back on the saddle as the saddle thickness allows. More modern still is a more wide spread practice of adjusting each string length individually.
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  #19  
Old 05-21-2017, 08:37 AM
MC5C MC5C is offline
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If you want to get closer to ideal than a simple straight saddle on an angle, you next add additional compensation for the B string. Next, you realize that for many string sets with a wound G string, the G and the high E need almost exactly the same amount of compensation, so with any kind of plain angled saddle one or the other is going to be wrong. So you divide the saddle in two, and have one little short one for the high E and B strings, so you can idealize the compensation for those two strings, and one longer saddle for the low E to G strings. That can let you idealize the compensation for at least two of those four strings. Now, you realize that while the G,D and A strings can be set really very close to idea with a straight line bridge, the low E string requires more compensation than a straight line from G to A will provide, so you can just file in enough more compensation to set the low E string ideally. So you can get extremely close to ideal with a two piece saddle with some additional compensation added in for the low E string. All that is generic. Now you get to exactly how much compensation is needed - completely dependent on string gauge (core wire gauge for wound strings is very important), string tension, action height, scale length, and tuning. Tuning to normal pitch, tuning down a step or two, D tuning, dropping to C, every single change means the idealized compensation changes.

I don't understand how people can put up with flat tops with simple straight bridges. At least on my archtops I can finesse the bridge, keep it simple, and get the intonation close enough that it doesn't bother me, but for years I played on .011's with unwound G, and a typical flat-top bothered the heck out of me. On most electrics you get a fully adjustable bridge, more ways to screw up but you can dial it it pretty close. Of course then you realize that if you change keys the octaves go out of tune (equal temperament rears it's ugly head), the bass strings go inharmonic above the 9th fret or so, and are out of tune with themselves, and you kind of give up and just play the thing...
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  #20  
Old 05-21-2017, 08:50 AM
redir redir is offline
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Quote:
Originally Posted by mercy View Post
Maybe Im not getting it or Im not communicating well. So you figure where the bridge is supposed to be on the actual top for the scale you have planned. You have decided to use a 1/8 or 3/32" saddle. You figure the comp needed for the E and e string. You rout that in the bridge. Some builders/brands just file the b string back from the break point on the middle of the saddle. Other builders/brands have multi filing points for comping each string.
What if you didnt do that filing. You just figure where the bridge is supposed to be and the angle for the E string and e string, route that as above. Then move the bridge back another 1/32. Wouldnt that eliminate the need for filing all those different break points?
Again, 1/32 is way too short. Otherwise that will work and be 'good enough' for 99% of the people out there. But you need to move the whole bridge unit back .1in.

I've been using the same saddle slot jig for 50 plus guitars which is essentially a predetermined angle, probably what Martin uses, from E to shining e. I then set the bridge on the top and measure from the nut down the center of the fretboard to the dead center of the angled saddle the scale length + .1in.

Rounding off the saddle and having a straight line from E to e is pretty much good enough but with a 1/8th inch saddle it allows you to then go ahead and tweak it a bit more as necessary.
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  #21  
Old 05-21-2017, 02:17 PM
mercy mercy is offline
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Thank you all for your patient explanations. I am coming away with, there is no way around individual string comping for good intonation. Ive learned so much from this forum over the years.
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