Bridge foot width

[pops1]

I have been wondering lately if the width of a bridge foot would make a difference in sound, and what that difference would be. The old Gibson single piece bridge from the teens is narrower than an adjustable bridge. What would narrowing the adjustable bridge do to sound? Was wondering if anyone has tried it. Thanks

[Ivan Kelsall]

Pops - You could always contact Steve Smith at Cumberland Acoustics for his ideas on that. He may have done some work along those lines in his own bridge design.

I know that the instruments are different,but i've messed around with banjo bridges a lot over 53 + years of playing - different materials / front to back thicknesses / heights etc. No wood i tried beat Maple,except to English Sycamore,which is a member of the Maple family anyway. Thicker,'front to back' bridges always sounded 'tubby' & if it wasn't 'thick enough',a bridge could sound 'thin' & the notes sounded weak. It's odd that Geoff Stelling's standard bridges are pretty thin compared to most,but his (my) banjos sound very good. I thinned down a cheap Grover banjo bridge & put it on my (once owned) Gold Star banjo & it worked wonders for the tone. My gut feeling is that the same thing wouldn't happen thinning down a mandolin bridge,but you'd have to try it to really find out - it could be fun,but if it doesn't work........... ?,
Ivan

[pops1]

Thanks Ivan, I have done some banjo bridges in the past myself and don't know why this popped into my mind, but there you are it is there so I am curious to see if anyone has fooled around with thinning the bridge. I may at some point when I have more time, but it will require fitting to the top just to see if it changes so a fair amount of work. Sooooo I am taking the easy way out first.

[sunburst]

Other than support the strings, the bridge does two main things: it adds mass to the center of the top and it adds stiffness to the center of the top. Take away material (to make the feet thinner) and you take away mass. That could perhaps change the sound, if enough mass is removed. Removing material to thin the bridge feet might reduce stiffness, but it seems to me not very much. My conclusion; a thinner bridge most likely will not sound much different, so considering the perhaps greater potential for tipping forward with narrower feet, and the perhaps added potential to compress the top wood, I'll leave it to others to experiment with thinner bridges and try to be objective in their listening evaluation.
I don't think there are enough similarities between banjo heads and relatively heavy and stiff carved mandolin tops, nor enough similarities between banjo bridges and relatively heavy and stiff mandolin bridges to draw much information from the comparison.

[sblock]

I suspect John's right. A thinner bridge base will likely dig into the top (more force per unit area), and might even destabilize it. The existing bases are already capable of making a mark on the top over time, as evidenced by many mandos. It will also be even more prone to tipping and leaning, which is undesirable. Furthermore, there's not much room for maneuver in changing the sound that way. Tweaks to the braces or the carving of the top would probably exert a much greater effect than thinning the bridge by a bit. For tweaking the sound, maybe you should just experiment with full contact bridges versus two-footed bridges, instead? Doing so would change the bridge contact area as well, but not at the expense of width, and therefore, of lateral stability.

[CarlM]

Red Henry's bridge work has been brought up before but here is a link to his bridge design page. He did some work with thickness and found at a certain point reducing mass and thickness made the sound thinner. His were all one piece bridges but he tried a lot of different woods and shapes.

https://www.murphymethod.com/index.c...t&contentId=87

[pops1]

Thanks everyone, I have followed Red Henry's bridge threads in the past. I am not sure why this thought came into my head, but thought I would put it out there. I have done several things to lighten my bridge and sound has improved considerably. that was months ago and was thinking of the teen's Gibson bridges and wondering. You are correct, most of them leave an impression in the top over the course of time.

[CarlM]

Just skimming through Red's page, I suspect there is an optimum point for thickness or maybe a range. there are obvious points where a bridge would be too wide and obvious points where a bridge would be too narrow. But it would take a bit of work to find the exact point and the risk, as has been point out is imprinting the top.

[Mandoplumb]

In more heavy built mandolins, I think removing mass from bridge helps. Years ago I had a Aria Pro 2 mandolin really good for the price and what was available at that time. I took the saddle off and drilled holes from bottom about 1/2 way thru or so. Improved mandolin considerably, till one day I took it out of the case and bridge had collapsed, so I know you can get too aggressive. My first " good" mandolin was a Flatiron and lighting bridge didn't seem to have any affect on sound so I haven't tried that in years.

[Ivan Kelsall]

John Hamlett is of course correct. Mandolin & Banjo bridges as well as the instruments, are very dissimilar - but,adding or removing mass to/from either should result in a 'change'. Whether that change would be for the better or worse,you'd have to try it out. I do know that i played a pre-war Gibson F4 belonging to a friend of mine several years ago,with a massive bridge on it. I assume that it was the original bridge,but there was enough wood in it for 3 bridges !!. Needless to say,it sounded dead. To make matters even worse,the strings were light gauge & the action very low. How much of the lack of tone/volume was due to the bridge alone i couldn't tell,but i think it would have needed very heavy strings indeed to get it moving.

Removing some front to back thickness on the bridge foot might not make much difference until you removed 'x' amount. I think that there would be a point where a change would occur,but for the better or worse ??,
Ivan

[Stephen Perry]

Keep in mind that the contact patch can be changed in shape by minor trimming without appreciable gross mass reduction.

I'm more of the opinion that carefully controlling mass distribution is of great import, more than contact patch, but have not the time for appropriately rigorous testing. If any donors are very very curious, I can do it for a paper!