compensated bridges??

[Willie Poole]

I have had an ongoing discussion about the "correct" was to install a compensated bridge saddle on the F model mandolins that are built to Loar specs...

The compensated "bouts" and not equally spaced on the saddle so there must be a preferred way to install them...I have always seen them installed so that the E string is the most forward (closest to the fingerboard) but also have see mandolins that are set up with the saddle flipped around 180 degrees from that...

Is there a correct way or does it depend on a persons preference?

Willie

[Mandoplumb]

I guess the correct way would be the way that it compensated the best. I have always found the E string forward works the best, probably not because the E needs to be the most forward ( you could move the bridge) but because of the A string in relation to the D.

[Loudloar]

The correct way to install a compensated bridge saddle is with the E furthest forward. Here's the reason: The E string is the most flexible and needs little compensation. The other strings are stiffer and therefore go sharp as they are played up the fretboard, so they need to have a longer scale to help them fret closer to true pitch up the neck. We know that no amount of compensation will make a fretted instrument play precisely in tune, it just gets it close enough so we don't cringe. And string gauge and core vs. winding diameters will also affect the compensation needed.

Having said all that, notice that if the saddle is flipped around backwards the compensation is not quite the same but is still roughly similar. That's why some people install them backwards and are happy and even argue that it's the correct way. Then look at an Asian bridge saddle. They are designed to be completely reversible, with the same (imperfect) compensation either way it is installed.

Steve

[pops1]

Occasionally I have installed it backwards if the foot is forward on the bass side to intonate. Installing it backwards helps the foot go straight across and not be angled forward. Rarely does this happen, but there is a mandolin for sale not on the classifieds that has the bass side angled forward.

[Dave Hanson]

Which direction is forward ? towards the tailpiece or towards the nut ?

Dave H

[Ivan Kelsall]

'Forward' is usually towards the tailpiece. If the bridge is flipped by 180 deg.,the E string section is still 'back' towards the neck,but to a lesser degree - how can you get it to be the 'most forward ?.
Here's Steve's diagram reversed :-
The E section is still 'back',but not by as much,
Ivan

[pops1]

I am speaking of forward toward the nut. If it were toward the tailpiece it would make the problem worse by flipping the saddle. If the Bass side is forward bringing the saddle slot back helps straighten out the foot. The fit of the foot is important and if it has to go at a noticable angle that fit is compromised.

[Loudloar]

When i said "forward" I meant toward the nut. So with the bridge below the nut is above and the tailpiece is below. The theory is that the E string saddle is placed about twice the distance of the 12th fret, but a little further to account for the string stretching as it is fretted. Then all the other string lengths are longer to compensate for their stiffness and the tendency to fret sharp.

Let's think about the result of flipping the saddle backwards. The G is longer than the E by the same amount either way the saddle is placed. But relationship between the E/A pair and the G/D pair is different. When flipped backwards relationship between lengths of the D & G is much greater and the relationship between the lengths of the E & A is less. So playing those pairs up the neck may not sound as sweet.

Ideally there should be no need to angle the entire bridge with a Gibson style saddle. I can certainly see the need to do that with the Asian style saddle since it has less compensation. But I replace any Asian style bridge with a Gibson style.

Steve

[sblock]

'Forward' is usually towards the tailpiece. If the bridge is flipped by 180 deg.,the E string section is still 'back' towards the neck,but to a lesser degree - how can you get it to be the 'most forward ?.
Here's Steve's diagram reversed :-
The E section is still 'back',but not by as much,
Ivan

No, no, you have this the wrong way around! "Forward" means towards the nut, "backwards" means towards the tailpin.

[pops1]

On a lot of saddle's the G slot is not as far back even tho the E is flush to the top. I have seen the E and G flush with each end front and back and for some that would be a way to stop the angled foot also.

[Willie Poole]

I have owned one or two Asian mandolins and never seen any like those "Asians" pictured here, I always speak of forward as being towards the nut also, I see now why I may have been at a disagreement with the person that I was discussing this with, he may have thought forward was toward the tail piece...We were probably both saying the same thing...

Thanks guys/gals

[Ivan Kelsall]

sblock - When I said 'forward',my understanding was that it was towards the tailpiece. OK,by majority vote,i might have been incorrect,but that doesn't alter that fact that the reversed bridge is like the inverted diagram i posted - the E strings are still further 'forward',but maybe not by as much. For anybody buying an un-slotted bridge,it could be a tad confusing.

It was interesting to note that the first time i removed the bridge from my Weber,i noticed that they had marked the bridge on the treble side to ensure that it would be fitted the correct way round.

Regarding forwards / back - top / bottom which is it ?. Is the tailpiece at the top or bottom ?. Are the highest (top) notes obtained on the top or bottom frets ?.

Since the mandolin comes already equipped with a ''front & back'',maybe we should be refering to 'up' = towards the nut, & 'down' = towards the tailpiece ?.That would be as we see the mandolin if it's held in front of us. That should make sense to all of us & it's less ambiguous than backwards & forwards (IMHO),
Ivan

[Phil Goodson]

......
Since the mandolin comes already equipped with a ''front & back'',maybe we should be refering to 'up' = towards the nut, & 'down' = towards the tailpiece ?.That would be as we see the mandolin if it's held in front of us. That should make sense to all of us & it's less ambiguous than backwards & forwards (IMHO),
Ivan

Not really. 'Cause we say "up the neck" when going towards the tailpiece when we're playing, don't we?
Maybe just "towards the nut" and "towards the tail" would suffice.

[acousticphd]

I guess the correct way would be the way that it compensated the best. I have always found the E string forward works the best, probably not because the E needs to be the most forward ( you could move the bridge) but because of the A string in relation to the D.

I've seen both these patterns and some variations, but I agree that the primary difference is whether or not there is a larger, unsymmetrical spacing between two neighboring courses. Which course "should" be the farthest forward is less important than how well the relative string lengths actually work to create more or less correct intonation.

Actually, the most persistent intonation problem I have experienced with the "Gibson" pattern is that it creates *too much* compensation difference between the E and A strings. If E is on, then A is flat; if A is on, then E is sharp (I'm talking about intonation from the ~7th fret and up). This had been the case with almost all my mandolins, but most especially the old Gibsons (!). I use 0.014" A-strings; I wonder if the Gibson compensation was based on a more common usage of heavier A-string gauges in the early days (eg, 0.016")? For this reason, the "Asian" pattern, or the "reversed Gibson" pattern, seems to work better to me for the A/E difference, but this can create some difficulty with the G string.

I try not to angle my bridge, because this creates string-length differences between the string pairs. I'd rather fiddle with filing the saddles to try to improve matters.
Of course, the (in)accuracy of fret placement on old mandolins, and differences in string gauges also come into play.

[Willie Poole]

I think the term "Up the neck" comes from the fact that the notes are higher and higher usually means up

[sblock]

I've seen both these patterns and some variations, but I agree that the primary difference is whether or not there is a larger, unsymmetrical spacing between two neighboring courses. Which course "should" be the farthest forward is less important than how well the relative string lengths actually work to create more or less correct intonation.

Actually, the most persistent intonation problem I have experienced with the "Gibson" pattern is that it creates *too much* compensation difference between the E and A strings. If E is on, then A is flat; if A is on, then E is sharp (I'm talking about intonation from the ~7th fret and up). This had been the case with almost all my mandolins, but most especially the old Gibsons (!). I use 0.014" A-strings; I wonder if the Gibson compensation was based on a more common usage of heavier A-string gauges in the early days (eg, 0.016")? For this reason, the "Asian" pattern, or the "reversed Gibson" pattern, seems to work better to me for the A/E difference, but this can create some difficulty with the G string.

I try not to angle my bridge, because this creates string-length differences between the string pairs. I'd rather fiddle with filing the saddles to try to improve matters.
Of course, the (in)accuracy of fret placement on old mandolins, and differences in string gauges also come into play.

As others have pointed out, compensation is an imperfect thing. Strings with slightly thicker cores (like the A and E in J-75s) produce more tension, and demand greater compensation, than thinner ones (like the A and E in J-74s). The core of the wound D string is thinner than the A, and it is deflected less due to the wrapping thickness, so it typically requires less compensation. The height of the action matters quite a bit, here, because that's what you are compensating FOR, after all: the extra sharpness caused by stretching the string as it gets fretted. No single, pre-cut compensated saddle can possibly work for all types of strings and differences in action. It's a compromise.

I would not worry for an instant about angling your bridge, however -- if that helps your sound. And mando folk have been doing this for years, so it's nothing new. I ran some numbers. A typical compensated bridge is about 4.5" wide in its base, edge to edge. Angling such a bridge by, say 0.2" from one end to the other (a reasonable amount) only introduces about 7/1000th inch (0.007") of a length difference between the two strings of a given course, which are typically separated by something around 0.15". Now, 0.007" is a minuscule amount, and it's TEN TIMES LESS than the 0.07" of difference from one side of the (now angled) bridge saddle to the other, assuming your saddle is 1.5" wide, which is typical. It is also a lot less than any of the differences in length introduced by the compensation notches in the saddle, which are typically about 0.1-0.2". Moderate angling of your bridge base therefore will not produce a significant difference between the pitches of any two strings in a pair. So, feel free to angle away, if that helps. Of course, it might not actually help, because it introduces some "extra compensation" that changes linearly, going from right to left (treble to bass) across the saddle, and that might not work out better for you. But if it does, it's a whole lot easier than cutting a new saddle with different compensation!

[Ryan Riordan]

To sort of weigh in here:

I had a conversation with my luthier the other day in which we talked compensation on my SS Stewart. Using a Gibson style bridge I struggle with the G course intonation, it is consistently sharp. But if I switch it, the A and E courses struggle. Similar to what Jeff described. My luthier's bread and butter is acoustic guitars and in talking with him, I found that he compensates EVERY saddle individually for his guitars.

I've seen a couple of posts showing adjustable ramp mandolin bridges, but essentially these were a jig for determining spacing for cutting bridges. I believe Paul Hostetter has one?

It seems to me that stewmac or LMI should make a tool for setting compensation and transferring to blank saddles.

[Timbofood]

That's what guitar guys do.
The mandolin is somewhat an instrument of "compromise" as has been stated ad nauseum on previous threads. The world is an imperfect place, (look at avocado pits)!
If you really get a hair about it, find your guitar guy a slab of ebony and let him lose sleep over getting it "perfect". Then the humidity will change (temperature, wind direction, blood sugar, blood pressure for sure) will change and it will be "off again" .
Get it close, play!
I've been at this for a fair length of time and,the minutia which is beaten to death about compensation and bridge fitting, has ceased to interest me much, I can worry and complain or, suck it up and play music!
If I changed bridges and saddle configuration as much as some of the people here I swear I would never play!
It's still called "Playing Music". "March or Die" as they say in the old French Foreign Legion! Maybe it's "Play or Cry" amongst mandolin worriers.

[Phil Goodson]

Several years ago one of my mandolins had over-intonation of the A strings when all the rest were near perfect. My luthier spliced in a small wedge of ebony to decrease A string compensation which completely solved the problem. Took him maybe 15 minutes total time. The fix is invisible.

[Paul Hostetter]

[Ivan Kelsall]

I honestly haven't examined them closely,but i'd be surprised if all 3 of my mandolin bridges were 'identically' compensated. The only one of them which doesn't require the "E" stings to be tuned up to match the "A" string fretted at the 7th fret after tuning across the fingerboard,is my Ellis. Both my Weber & Lebeda do. The raise in pitch required is very tiny, & when done,there are no intonation problems.

My Weber has one of Vern Brekke's designs,My Lebeda has what i thought was a Cumberland Acoustics bridge on it - but it ain't,it's very 'similar'. The Ellis bridge,judging by the skinny,'steel looking' thumbwheels on it, doesn't appear to be a CA bridge either,but the compensation is very accurate,judging by the intonation up the neck,
Ivan

[Willie Poole]

I notice that on everyone that Paul showed the A string compensation is in the same place and that is usually the one string that never has the correct intonation...I have three mandolins and all of them intonate correctly on all strings except the A strings and when tuned to note true at the 7th fret they note flat at the 12th and sharp on the 3rd, it isn`t enough to get upset about so I just keep playing them like they are...I have worked on the nut and bridge slots and can`t seem to find any answers by doing that either...I leave them all like the "Gibson" pattern as shown by Paul...

Thanks to all who responded...

Willie

[Dale Ludewig]

Ivan, that could be a James bridge on the Ellis.

[Timbofood]

Paul's closing line addresses the issue very clearly,
"Individual adjustments may be required for personal needs." To paraphrase.

[pops1]

Willie, a lot of string sets have a .015 A string, I know you use GHS A270's and they have a .016 for an A. Maybe it requires a different intonation for the larger string. Seems I have fought the A string more than any other.