Just as important as location is in assessing real estate, the location of your bridge can also mean the difference between a hot item or a piece of property no one wants to touch. You can jig up all you want but that jig must accurately place that saddle (where the strings cross) in the right spot. Since setup can also include intonation, we must first determine that the bridge is located within certain parameters. A mislocated bridge will cause an otherwise beautiful instrument to sound progressively sour in the higher positions.
Then there is the left-to-right alignment which will center the strings across the fingerboard. This is far more important than how it looks in relation to the center seam of the top. If you get one crooked neck-you going get crooked bridge. No can help. It will be off center line, but keep the strings CENTERED. When playing, you don't want the strings so close to the edge that they roll off the fret ends as you finger a note on the 1st or 4th string.
Ok-so we can easily align the bridge (actually, saddle ends are what were looking at) left to right with string, straight edge, whatever. What about the north to south direction? I go with a full 1/8" of compensation. Compensation is the ADDED distance beyond the line length or actual measured length of your fret scale. Let's say you have a 17" Tenor scale. If you butt your ruler againest the nut you will measure 8 1/2" to the crown center of the 12th fret. So one might think that the leading or north edge of the saddle should be 17" (or twice that). It would be in 2D. That would be the exact location of the saddle if the strings didnt stretches you played a high note. But you will see that in the higher positions the string needs to travel a greater distance to the fingerboard/fret causing it to stretch a bit. This stretching translates to the raising of pitch (sounding sharp) compared to the true octave. We compensate for that by locating the saddle MORE thatn that 8 1/2" south of the 12th fret. It will NEVER be LESS than the line length or what we call scale length. Therefore, I measure 8 5/8" (1/8" of compensation) from the 12th fret to the north (leading) edge of the saddle. I know that Ill get some disagreement with this amount of compensation beacuse the 1st string or A string might sound alittle flat at the octave 12th. Yes, but in real playing situations one will most likely bend the string enough to compensate for this over compensation. The area of saddle under the 2nd or 3rd strings need to be peaked at its south edge.
Final shaping or of peaking of the saddle should look like a smile for high G tuning and the peaking of the saddle should look like a wave in low G tuning.
Why? Thicker diameter strings need greater compensation than thiinner ones. Ive found that this is the best AVERAGE saddle location for an 1/8 thick saddle. I dont feel like I get accurate intonation with a thinner saddle.
Whether you use locating jigs, drill holes through the saddle slot, or some other means of fighting glue up creep , thats up to you. Bridge thickness or saddle height can be altered after glue-up. You will still be in tune. So remember with location, location, location.
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