setting intonation

[jambalaya]

So, i had a problem for a while trying to set the intonation properly with all the strings at tension. Whenever i tried to scoot one side, the other would rotate too. i'd also have problems with marring the finish in the process. So, the last time i changed strings i took them all off and sat the bridge between the middle points on my f holes and put on the lowest g and the highest e and tuned them up. i then set the intonation of one string and retuned both. then i was able to hold that side down and set the intonation on the other string. without all the extra tension i was able to move just one side at a time and not mar the finish. when i strung it up the rest of the way, all strings were perfectly intonated. this might be common knowledge for some, but it was new to me so i thought i'd share.

sorry i just realized this was the wrong forum. i'm not sure how to move it.

[Randi Gormley]

You can also set the intonation on one side and mark it on a piece of Post-It you put at the outer edge of the bridge so you can return it to the proper place if it moves. I've done that when I had a problem.

[Tobin]

I've used a similar process to the OP when setting intonation, but instead of removing all the strings, I just loosen them all up until I can shift the bridge. I use the outer two strings to test, and then bring all the rest up to pitch. Final step is checking to make sure the saddle hasn't leaned forward in the process of tensioning all those strings.

[jambalaya]

thanks for that tobin. that'll help me when it's time to adjust, but not time to change strings.

[Bill Snyder]

thanks for that tobin. that'll help me when it's time to adjust, but not time to change strings.

Change one string at a time and the bridge stays in place. It never occurred to me to do it any other way unless I wanted to take the bridge off to make adjustments to the ramps on the bridge.

[jambalaya]

i find the bridge shifts over time and the intonation changes. just keeping the bridge in place while changing strings doesn't mean the intonation is still correct. that's my experience anyways.

[Tobin]

Your bridge base should not be moving over time. The resultant force from the strings "breaking" over the bridge will keep it firmly planted on the sound board. What does change the intonation over time is the saddle leaning forward, or the strings going dead. Personally, I can't seem to get more than 3 weeks out of a set of strings before the intonation is so far off that I can't stand it any more. Changing them out (one at a time) solves it. You shouldn't have to correct the bridge/saddle position on a frequent basis. If you check the saddle to make sure it's not leaning as often as every 2nd or 3rd string change, you should not have any noticeable intonation changes going on.

[acousticphd]

all strings were perfectly intonated

I also use a combination of what you and the other posters describe (marking the position of the bridge foot before moving or adjusting, and loosening or removing some of the strings when trying to shift the bridge).

Intonation is always a compromise, unfortunately (as I guess you already know). It is nigh impossible to perfectly intonate all the strings, even just at the 12th fret, without some additional series of adjustments. The compensation varies among different bridges - in my experience, the A-saddle usually has too much compensation and notes flat vs. the E string, and the D string can note either flat/sharp). Simply angling the bridge, as we're talking about here, ensures that the two strings of the same course will have slightly different lengths. I usually focus on getting the best compromise intonation at the ~7th fret for the E/A strings, esp. on my old instruments, which tend to have more intonation discrepancies over the first 5 frets.

[Mike Bunting]

i find the bridge shifts over time and the intonation changes. just keeping the bridge in place while changing strings doesn't mean the intonation is still correct. that's my experience anyways.
I regularly adjust my intonation. The first place I hear it going out is on the open E and the A string 7 fret E doublestop.

[Bernie Daniel]

Your bridge base should not be moving over time. The resultant force from the strings "breaking" over the bridge will keep it firmly planted on the sound board. What does change the intonation over time is the saddle leaning forward, or the strings going dead. Personally, I can't seem to get more than 3 weeks out of a set of strings before the intonation is so far off that I can't stand it any more. Changing them out (one at a time) solves it. You shouldn't have to correct the bridge/saddle position on a frequent basis. If you check the saddle to make sure it's not leaning as often as every 2nd or 3rd string change, you should not have any noticeable intonation changes going on.

I experience the same thing - gradual loss of intonation caused by the bridge tipping forward (toward the headstock) due to tuning. I do find it useful to reset the bridge say every couple of months or whenever it needs it. The technique has been described many places but briefly you just put both thumbs on base of the bridge (tail piece side) and then get a good grip on the saddle with your index fingers (headstock side) and then push on the base while pulling on the saddle toward you. Make it a very firm but smooth coordinated PUSH (toward the headstock --thumbs)-PULL (toward the tail piece -- index fingers) action (it takes pretty good force to do it) but the bridge will snap up right every time and it should not move on the top.

[Mike Bunting]

I experience the same thing - gradual loss of intonation caused by the bridge tipping forward (toward the headstock) due to tuning. I do find it useful to reset the bridge say every couple of months or whenever it needs it. The technique has been described many places but briefly you just put both thumbs on base of the bridge (tail piece side) and then get a good grip on the saddle with your index fingers (headstock side) and then push on the base while pulling on the saddle toward you. Make it a very firm but smooth coordinated PUSH (toward the headstock --thumbs)-PULL (toward the tail piece -- index fingers) action (it takes pretty good force to do it) but the bridge will snap up right every time and it should not move on the top.
I just take it into the shop and have the guy that works on my mandolin adjust it.