Mahcks
53 posts
Aug 28, 2015
2:23 PM
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Why are reeds rectangular? Why aren't the free ends rounded or even triangular?
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Philosofy
720 posts
Aug 28, 2015
3:05 PM
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They would work fine, but would be harder to fix properly, and harder to manufacture. Reeds are made en masse. If a reed was a little too long, you can just snip the end off. If the end has to be rounded, it would be a major PITA to fix that. Also, as a curved blade would dull (for cutting the end of the reed), then it would be harder to sharpen. Straight blades are easy.
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STME58
1459 posts
Aug 28, 2015
3:25 PM
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I agree with Philosofy. Also the mathematics involved in calculating the natural frequency are a bit simpler with a rectangular reed.
Take a look around Pat Missin's web site for a lot of info on reeds. WHAT IS A FREE REED
I have a few Bawu with the triangular reeds. They are a good instrument for a harmonica player because you already have the required breath control.
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nacoran
8646 posts
Aug 28, 2015
6:52 PM
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I like questions like this, and I was going to point out that there are a few free reed instruments with triangular reeds but it looks like STME58 has beat me to it, and even included the link I would have, and I think Philosofy and STME58 have probably nailed down the reasons too.
I have wondered sometimes what would happen if you changed the far end of the slot so that there was a slope that would roughly follow the end of where the reed swings and if that would make things more airtight (you couldn't really do anything for the draw reeds unless you did something crazy with valves because you need to be able to blow past them). I'm always fascinated with the little decisions that have been made in standardizing harmonicas that you often just accept as how they are. I seem to remember David Payne was posting some links at one point about some old harmonica patents. At least one harmonica had it's reeds 'sideways'. There weren't a lot of details. I've wondered about that, because it might be possible to set up a harp where each reed was used twice, for instance it would be the left reed on the 2 hole but the right reed on the 1 hole, which could do interesting things, but it would also mean that you'd have to have a separate reed mounting for each reed instead of just two reed plates and I'm guessing it was probably all blow, because to make it blow draw in that configuration would be kind of tricky (maybe with valves?). Unfortunately the patent drawing wasn't terribly illuminating.
I think there was also a Seydel back in the 70's that flipped one of the reed plates over, which for some reason made it virtually impossible to choke a reed, which is great for folk stuff played loudly but I guess limited bending. (I've never played one and may be remembering the details wrong).
It seems there are reasons for lots of these little things in harmonicas but a lot of it seems to be just figured out once and passed down without explanation.
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Nate
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GMaj7
752 posts
Aug 28, 2015
7:21 PM
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Good question..
STME58 knows this stuff inside/out..
The reeds are STAMPED using rectangular tools with sharp edges.
It is a common technique used by a lot of German manufacturers in light industrial, tools, musical instruments, and some medical.....The process has been around for 200 years...
The stamps used today are some of the same ones used 50-75 years ago.
The harmonica purchasing market goes nuts when the base price of a Marine Band goes up $1.00.
Hence, there is no financial incentive to move to more modern manufacturing techniques which would jack the price up considerably.
Great question...
Good answers and comments by all..!
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Greg Jones
16:23 Custom Harmonicas
greg@1623customharmonicas.com
1623customharmonicas.com
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Mahcks
54 posts
Aug 29, 2015
8:09 AM
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Thanks for the answers, yall. I'm not surprised that manufacturing had something to do with it, and there's a new instrument to get (any advice on looking for a bawu?).
Maybe we might see some new ideas with the increasing availability of 3d printing and desktop cnc machines.
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STME58
1460 posts
Aug 29, 2015
9:15 AM
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(any advice on looking for a bawu?)
Shenzhen Musical Instrument mall
I realize this isn't practical for most of us, but if you are ever in Shenzhen (where half the worlds cheap manufactured stuff is made, just across the border from Hong Kong) this music center is worth visiting. There are about 3 floors of musical instrument vendors, both Chinese traditional and western orchestra instruments. This is where I bought some of the Bawu, Halusi and Dizi (if you look hard you can even find a diatonic harmonica or two) I have as the company I work for does some manufacturing in the area. Lately we are manufacturing in Thailand. I have found a good music store in Bangkok that I have gotten a saw duong, ching and a khim. I post this info just in case you ave any travel plans or may know people who go to these areas. Both of these stores are worth visiting if yo are a musician and are in the area. Both of these stores are hard to find and when you first walk in the building you think you are in the wrong place because there are no instrument stores on the first floor.
Last Edited by STME58 on Aug 29, 2015 9:18 AM
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mlefree
392 posts
Aug 30, 2015
9:18 AM
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I wonder if there would be any theoretical advantage to a non-rectangular reed shape, manufacturing issues aside.
Thanks,
Michelle
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SilverWingLeather.com
email: mlefree@silverwingleather.com
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Philosofy
721 posts
Aug 30, 2015
12:45 PM
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I just read an article about a new, custom chromatic. Think what Brad Harrison tried to do, but with a chrom. And they got it right.
http://www.chmel.at/nc64/specification.html
I believe the reeds are tapered: not as wide at the top. A light load at the end might lessen the stress at the base, so the reeds don't break as often. Also, the material and crystal structure of the reed's metallurgy will have an effect, as well as the smoothness of the reed's surface.
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STME58
1462 posts
Aug 30, 2015
11:18 PM
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Interesting that they used EDM to make the reeds, the specification says the reeds are conical. If this is true they are not only wider at the root, but thicker and have a curved surface. This is certainly possible with EDM but I am not sure why you would do it. Having the reed wider or thicker at the root would raise the pitch, having the reed thinner at the tip also raises the pitch. That is why the reeds have the thick sections on the tips. The thick tip might change the valve action as the reed opens and closes. Most low tuned standard harps have thick tips like this also. If I get a chance I will model a reed like this and see if anything jumps out of the modal analysis.
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Philosofy
722 posts
Aug 31, 2015
7:49 PM
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I can't wrap my head around conical reeds. I would think that flexing a curved surface would cause more stress, and more broken reeds.
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