Volume and Bridge Height

**yankees1** · Jun-23-2012, 6:54pm

As a general rule, will raising the bridge increase the volume if the action is low ? I realize that it depends on how much it is increased also.

**Philphool** · Jun-23-2012, 8:28pm

My experience with multiple mandolins has been that, if I lower the action to a very, very low level (below 3/64"), I begin to lose volume. I don't really see much difference between 3.5 to 5 sixty-fourths inch. Higher than that, I can't tolerate.

Different mandolins do seem to have a slightly different theshold.

**sunburst** · Jun-23-2012, 8:59pm

If the action is higher, you can play harder, so you can play louder. The mandolin probably isn't any louder, but since the strings are farther from the frets, you can "hit it harder". Since raising the bridge raises the action, many people have come to believe that higher bridges are louder. In fact, there is little (if any) direct correlation between bridge height and loudness, and there is little direct correlation between string break-over angle (and the associated difference in downward pressure on the bridge) and loudness.
So..., as a general rule, no, raising the bridge does not increase volume.

**Ivan Kelsall** · Jun-24-2012, 2:29am

John - In all humility i bow to your superior knowlege re.bridges,string heights etc..I have to admit that i've always thought that having a higher bridge,did indeed give more volume.On a mandolin,i can understand fully the point that you made above,regarding higher strings allowing you to pick harder,hence more volume. However,on banjos,which again,you know far more about than i do,it's not uncommon to have a 1" high bridge & a neck angle adjusted to lower the action,so that you get an ease of playing AND the volume. I know that banjos & mandolins are totally different,but are they so different that you can achieve more volume with a higher bridge on a banjo,as well as having a low action,than you can on a mandolin ?.
Several years back,i bought one of the recent Gold Star 're-issue' banjos. It came with a bridge that was too low in my opinion,so,i bought a bog standard Grover bridge 11/16" in height,fitted it,adjusted the neck angle & the difference was very pronounced. It was even more so after i'd thinned the bridge to the same thickness as my Stelling banjo bridge.I always put the difference down to the height of the bridge - i'm puzzled !,
Ivan

**sunburst** · Jun-24-2012, 8:00am

On a banjo, a higher bridge, which creates more downward pressure, tightens the head making it stiffer. On a mandolin a higher bridge and more downward pressure does not make the top stiffer. That is why raising or lowering the tailpiece or the bridge on a banjo makes so much difference, and raising or lowering the bridge or tailpiece on a mandolin makes so little difference.
Also, the static downward pressure of the strings on the bridge isn't really a contributor to sound. It is the dynamic effects of the moving (plucked) strings that makes sound, and the static and dynamic effects on the top aren't closely related.
Further, though a higher bridge (or lower tailpiece) on a banjo does adjust the sound, I'm not convinced that it gets louder with a taller bridge. Also, the OP's question was about action height rather than bridge height, and action height and bridge height are two different things.

**Brutus1999** · Jun-24-2012, 8:33am

Yeah -- everything in the universe is curvelinear -- a fancy way of saying "has limits". A banjo bridge too loose will not have maximum volume. A banjo bridge too tight will also lose volume after a certain point. (Not that I'm admitting that I own a banjo...or five...or more)

**fiddler37** · Jun-24-2012, 9:22am

They probably exist, but I have never seen a 1 inch banjo bridge. There are 11/16, 5/8, 1/2 inch bridges etc. Most quality banjos with a properly fitted neck, do not have enough adjustment room to go from 1/2 to 11/16 without putting a "warp" on the rim or shaving some wood off of the neck. If too much wood is removed, then you will probably have to use a shim to go back to a lower bridge and a proper neck fit.

**yankees1** · Jun-24-2012, 9:49am

Originally Posted by sunburst

On a banjo, a higher bridge, which creates more downward pressure, tightens the head making it stiffer. On a mandolin a higher bridge and more downward pressure does not make the top stiffer. That is why raising or lowering the tailpiece or the bridge on a banjo makes so much difference, and raising or lowering the bridge or tailpiece on a mandolin makes so little difference.
Also, the static downward pressure of the strings on the bridge isn't really a contributor to sound. It is the dynamic effects of the moving (plucked) strings that makes sound, and the static and dynamic effects on the top aren't closely related.
Further, though a higher bridge (or lower tailpiece) on a banjo does adjust the sound, I'm not convinced that it gets louder with a taller bridge. Also, the OP's question was about action height rather than bridge height, and action height and bridge height are two different things.

Hate to admit my ignorance which I'm sure I have a long time ago but ------- how else would you raise the action without raising the bridge ?

**fiddler37** · Jun-24-2012, 2:11pm

Changing bridges is one way. The coordinator rods can be used for small adjustments, if you know what you are doing. If you do not know how, it is easy to do some damage. There is some information on the internet on how the the rods work. There are also people around and perhaps a music store in your area that can make the adjustments for you.

**Ivan Kelsall** · Jun-26-2012, 2:51am

Many thanks John. I got my idea re.banjo bridge height & volume from the book "Masters of The 5-String Banjo".The section on Bela Fleck where he talks about getting his pre-war Mastertone pot & getting the banjo put together. He mentions that he put on a 1" high bridge for the added volume.I made a broad (and incorrect) assumption that the same would apply to most instruments,
Ivan