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Can anyone shed some light on this for me? On a movable bridge instrument, is there thought to be any effect from tilting the top of the bridge toward the tailpiece as opposed to the bridge forming a right angle to the working length of the string? Just to be clear, I am not talking about slanting the bridge for intonation. For instance, if I have a 12 degree string breakover angle at the bridge (which is perpendicular to the top plate) and I tilt the top of the bridge 6 degrees toward the tailpiece.
Anyone know of the pros and cons of this? Maybe it doesn't matter one way or the other. I know I have seen banjo bridges set this way.

Thanks,
Kent

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Kent Schoonover

WWW.schoonoverresophonicguitars.com

Kent my friend I don't know the answer to your question but I wanted to bump this thread for you in the hopes that others might help you out.

In the acoustic guitar world (flatish top) some builders do angle the saddle back and I have heard of them doing this up to 6 degrees. The stated reasons that I have read before is that it makes for better contact with the top and reduces the possibility of the bridge cracking in front of the saddle. I have not heard, or don't remember hearing that there is any sonic benefit. Of course these are not movable bridge instruments. So in short - I don't know......

Also I checked out your web site and would encourage everyone to do so! It's one of coolest sites that I have seen and the music that plays while pictures of your beautiful guitars are displayed is just over the top cool too!!!!

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Ann Arbor Guitars

I have seen the practice done before. The luthier told me it was to get a better break angle over the saddle. I asked if he had any studies to prove it and he said not. If you move the bridge to get a better brake angle , you also have the line of force changed. It really doesn't do anything.
There are physics involved and when you figure resultant forces applied , changing the angle will give you more force at the top but since you angled the bridge you won't get that number at the bottom. Think of it as a pool shot , all you did was change the angle of the force. When in doubt you can try it and see for your self.
If something like this was a positive for the sound , I am sure we would have generated to this a long time ago.
john hall
blues creek guitars

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Are you referring to the tilting of saddles on acoustics as well, John, or just tilting the entire bridge on an electric or movable bridge instrument?

I haven't decided which side of the fence I'm on yet, but I'd like to take your opinion into account (and be sure I'm hearing right )

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I don't understand what the OP wants to achieve. If it's an improvement in sound, I'm very dubious. Or is it to keep the bridge from tipping over?

But changing the angle, if the height and scale remain the same, will not change the force on the top (or bottom, assuming a rigid bridge) of the bridge, nor will it change the break angle; it will only change the force vector direction relative to the bridge foot. And we did start doing this long ago--on all the members of the viol and violin families. Not by angling a movable top piece (which strikes me as a bad idea; but having a top section to a bridge that can be tilted around so much strikes me as a bad idea in any case), but by putting the crown of the bridge at the tailpiece side. The purpose is to keep the force vector inside the bridge foot, so it won't tip.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

From a purely physics perspective, the angled bridge would cause a bit of torque on the saddle up in front, down in back, thus somewhat counteracting the pull of the strings from the rear part of the saddle.

Edit: Or pretty much what Howard said...I got interrupted for a long time between starting and ending this post.

If you assume that the tension on the string is the same in front of the saddle and behind it, then the resultant force vector is along the bisector of the break angle. If the saddle is vertical then you can resolve that resultant on the saddle top into two vectors; one pushing downward on the axis of the saddle, and one tipping the top of the saddle toward the nut. That tipping vector has to be taken up by the wood in front of the saddle. If the saddle is back angled so that it bisects the break angle, then the resultant is all along the axis of the saddle; there is no tipping foce and no stress on the front of the bridge.

Rich Turner, who is pretty savvy, says that USTs work better under a back angled saddle, owing to the greater static down force. Like him, I use a 9 degree back angle.

I was taught to cut violin bridges so that the bridge centerline axis is on the break bisector. If you don't do this there is a tipping force on the bridge that eventually causes it to warp toward the nut, and this warp costs you some sound (note: not the angle, the warp). Because the violin bridge is itself tapered it often happens that the back face is perpendicular to the top, and that's the usual way the rule is stated.

On something like an archtop guitar it probably doesn't make much difference how you tip the saddle, just so the resultant is within the footprint of the bridge base. You'll know it if it's not!

There is a torque on the top of any fixed-bridge instrument, due to the saddle height off the top. There is some discussion about whether the break angle effects this, but within that I would not think that the saddle angle, whether it's along the bisector or not, would make any difference. I'm hoping to do some break angle testing some time soon, but don't have any plans to look at saddle angle in there: you've got to stop some place!

Hey Hesh, thanks for your input and flushing out those responses for me. I appreciate your visit to my website and your kind comments as well. I have recently been made aware of builders installing their saddles on flattops as you described and it makes perfect sense to me.

Thanks John and Bob. Just for context, I wasn't thinking of tilting the top bar on an adjustable bridge

Howard, thanks for responding. I agree with your comments. My intuition tells me that the bridge should bisect the string break angle to align the force with the bridge feet. By doing that, it would seem to remove the lateral force at the top of the bridge that could tip the bridge over. I thought violin family instruments were that way, but wasn't sure.
I guess I was really wondering if anyone knew of any tonal advantages to tilting. It would seem to me that the string vibrations would be driven more directly to the top. But would there be any discernible difference? I guess it would be hard to quantify.

Anyone else?

Thanks,
Kent

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Kent Schoonover

WWW.schoonoverresophonicguitars.com

Thanks Alan. I was hoping you would chime in. I have seen the bridges on old violins curved toward the nut. And I am glad you brought up the USTs. That in itself is a good reason for the tilt.

You guys are great.

Kent

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Kent Schoonover

WWW.schoonoverresophonicguitars.com