Tone bars [Archive] - Mandolin Cafe Forum

testore

Dec-21-2006, 1:59pm

Anyone care to share some pics. I usually take notes on all my bars.On violins I have done it every time.It's more hit and miss with my mandos.I decided to take a few pics for reference. I recently got to see inside of a distressed Gibson MM and they looked very wierd to me, but it got me wondering,....maybe I'm the wierd one.Mine are obviously derived from my violin background. What do otheres do? I'm getting a great tone from this one.When I hold both bars between my fingers and tap the treble side it rings two notes,C natural and A. The bass gives me A an octave lower. Just the way it should be I think. Anyone else? Engleman,BTW

testore

Dec-21-2006, 2:01pm

Top view

testore

Dec-21-2006, 5:10pm

thanks Shayne, but noone else has anything to say. Am I that far off the map?

Antlurz

Dec-21-2006, 5:21pm

I would think that holding it by the bars and tapping it would give you anything BUT an accurate example.

That's about the way I shape some of mine too.

Ron

testore

Dec-21-2006, 5:25pm

your right. i never know what that's telling me, but it has a nice complex quality, that's all.

superc_1

Dec-21-2006, 5:30pm

THESE ARE THE KIND OF PICTURES I LIKE TO SEE. MY TONE BARS ARE A LOT SHALLOWER THAN YOURS. I WONDER IF THE YOU LEAVE THE BARS THICKER DOES THAT INCREASE VOLUME OR DECREASE VOLUME (THAT THE BEST WAY I KNOW HOW TO EXPLAIN THE QUESTION) THANKS

testore

Dec-21-2006, 6:11pm

my bass bar is thicker and taller than my treble bar, but i've never played with anything much different except for my X bracing. mine is assymetrical but i haven't seen many to know how others do it. i've had very nice results doing it my way so i don't want to wander too much.
another thing, the Gibson bars were shallower too, but scalloped so that they appeared to be lower in the center than the ends.a very strange idea from a violin makers point of view.

craigtoo

Dec-21-2006, 6:48pm

This one was built for me by Yann Ecorchard - he used the plans from Adrian Minarovic

More images available here

New F5 (http://homepage.mac.com/craigtoo/PhotoAlbum50.html)

I'm not a luthier, and I don't even play one on TV...hope this gives you another "data point" at least...

Craig
www.craigharbauer.com

http://homepage.mac.com/craigtoo/.Pictures/Photo%20Album%20Pictures/2006-12-21%2015.40.47%20-0800/Image-A4990B2E914B11DB.jpg

Michael Lewis

Dec-22-2006, 3:16am

Gary, your bars look symmetrical, the Gibson ones aren't. Typically the treble bar extends nearly parallel to the edge of the fingerboard while the bass bar splays out at a wider angle. The reason the Gibson bars look "scalloped" is they are shaved in the process of tuning them. In the violin world the bass bar is a structural support, while in the mandolin world the tone bars are for tuning the top (tone bars, get it?). Assuming good materials, a properly carved top is strong enough to support the stress without the tone bars. That's my story and I'm sticking to it. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif

Hans

Dec-22-2006, 7:13am

Gosh, my camera stopped working! #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

LeonEvans

Dec-22-2006, 10:50am

This is a picture of my C-5 during its build. Stephen Holst is the builder.

Leon

ashemando

Dec-22-2006, 11:07am

According to Siminoff's diagrams in his excellent text, the
tone bar orientation is indeed quite asymmetrical.How does that impact top displacement and tone? Not sure but the few I have built were done per Siminoff's book and they sound good.Who really knows?

Walter Newton

Dec-22-2006, 11:17am

You can see couple of Phoenix mandolins under construction at these pages, a few of the pics show the (graphite laminated) tone bars.

http://obyank.fotopic.net/c594002.html

http://world.std.com/~ereilly/fnx.html

amowry

Dec-22-2006, 11:35am

Gosh, my camera stopped working! #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif
The shop dust finally got to it, eh? It's only a matter of time.

Paul Hostetter

Dec-22-2006, 11:39am

Hans - change the batteries! I always like looking at what you're up to!

Bill Van Liere

Dec-22-2006, 11:49am

Hans - change the batteries! #I always like looking at what you're up to!
I'll bet you do Paul.

My pinkie knows that the braces in My Model 21 are different that what is pictured

testore

Dec-22-2006, 12:10pm

Michael, My assymetry comment was for my X braceing. But I will have to disagree with you somewhat. Mandolin bars are very structural,don't you think? With the soundpost in violins, the bassbar is doing less to support the top than tone bars in mandolins aren't they?I know it's impossible to prove but that's the way I approach the bar thing. Hans once told me that he has tried every kind of bar and placement and said that he hasn't found a consistant flaw or advatage in any of them. They all work to some degree. Maybe we think too much.

sunburst

Dec-22-2006, 12:17pm

Virzi Shmirzi!
Here's the real secret to tone, a whole 'nother top with tone bars and all!

I knew I had this snap-shot somewhere, poor quality though it may be, but it took a while to find. I had the mandolin top lying inside of the octave, so I just snapped the pic.
The bars are pretty close to the F-5 positions, and within a small fraction of an inch of the Siminoff measurements. I thought of experimenting with moving them around, but Don MacCrostie said he tried that and didn't hear any difference (he's on record with that statement, or I wouldn't speak for him) so I breathed a sigh of relief and just kept them where I have them since they seem to sound fine right where they are.

tumblewead

Dec-22-2006, 12:26pm

This is a IV Kit I recently finished on which I cut an oval hole. Went with tone bars and placed them according to Siminoff plans.

Michael Lewis

Dec-23-2006, 2:30am

Well, there are many ways to get'er done. There are many many approaches to making mandolins but what I am generally referring to are the 20s F5 models. I have a CAT scan of one, and the cross sections show the bars to max out about 1/4" in height. Granted, that is only one example, but so far all the Loars I have put my pinky into have had similar bars. If you consider the concave surface the bars are glued to, direction of force from the bridge, and the small bars, you should see there is minimal stiffness added by the bars.

Now if you look inside an import mando you will probably see some honking timbers that are making sure the top doesn't cave in. Surprisingly, some of these instruments actually sound pretty decent, but they don't sound like a Loar.

sunburst

Dec-23-2006, 8:57am

Michael, my experience squares with yours. All the Loars I've seen have fairly small bars.

It seems to me that the "extremes" of mandolin top construction are:
-thick top wih small bars, and
-thin top with large bars.
I believe I see quality examples tending toward both extremes built by well known builders. It seems that one of the ways builders develop their unique sounds is through the position they eventually take in the thick/thin top; small/large bar continuum.

THEBIGV

Dec-23-2006, 11:49am

Great reading, gives me something to ponder while I am http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif waiting on Santa.
I also think that the rate of graduation from the center of the top to the recurve, as well as the height of the tone bars, has impact on the sound that comes from the top. (more bass, more treble, and so on) All this of course has effect on the flexibility of the top, and therefore different tones. I have learned so much from reading your posts. thanks to all of you.
Charlie

testore

Dec-23-2006, 12:09pm

I alter bar size with wood choice. Red spruce gets smaller bars.Not quite 1/4 inch but smaller than Engleman.This is a great topic, and since there are alot of really nice sounding mandos, then there is obviously not one right answer......kind of comforting to know.thanks guys,
Gary

Stephanie Reiser

Dec-23-2006, 10:01pm

sunburst

Dec-26-2006, 7:40pm

Stephanie, it's Paulownia.

Dale Ludewig

Dec-26-2006, 8:33pm

Michael, 1/4" max in height? That is amazing. I've never had the chance to see such. And the tops were graduated as we see in the best plans? Why do you think that the dimensions for the bars are so much taller in the plans we see? Or am I misunderstanding something?

Dale

Michael Lewis

Dec-27-2006, 3:27am

Dale, the CAT scan is not supposed to lie. The scan of this '24 Loar shows just that. Maybe 5/16", but definitely small bars. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif