 The Clarinet BBoard
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Author: alanporter
Date: 2009-06-23 17:37
When the mpc table is said to be concave, is the concavity longitudinal or transverse ?
I have a bunch of old cheap mouthpieces that I am going to practice altering , partly for education but more for fun.
Thanks.
Alan
tiaroa@shaw.ca
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Author: Brad Behn
Date: 2009-06-23 19:12
Table concavity is something that varies a lot. Nearly all machine made mouthpieces have some concavity, and usually it is more oval than on the longitudinal axis. This is due the nature of the manufacturing process. As it is machined, heat builds up and the belly of the table swells up, causing the cutting tool to remove the higher spot in the middle of the table.
In my opinion, Vandoren mouthpieces have the best commercial concavity because it isn't as deep. Some mouthpieces like the Zinner blank tend to have very deep concavities and it is less of an oval shape and more on the longitudinal axis.
As you work your tables, using a straight edge, you can witness the concavity diminish. In fact if it is a machine made mouthpieces like a Zinner blank, you can watch the concavity reduce with each pass because the surface texture from the sandpaper will appear different than the machine polished surface texture from Zinner. I have found that in removing the entire Zinner concavity it takes quite a bit of work. But for me it is worth it because the mouthpiece ends up more lively and resonant. To fully remove the Zinner Concavity requires perhaps 2 table passes with 400 grit, and 1 pass with 600 grit 3M wet or dry sandpaper. The problem then becomes that the rails and table become very wide, and I must reshape, sand, and buff to make the mouthpiece true to its potential.
Of course, many prefer the duller, tight, dark, compact resonance of the Zinner blank with the table concave, and the facing short, so I leave it up to my clients to decide which one they prefer. There is no right or wrong. It is ultimately a subjective thing.
Vandoren tables are nearly flat with only one pass on the paper.
It is also important to note that once the table is flat to the eye, it may very well not be flat to a straight edge. Of course how the mouthpiece plays is of key importance, but for those who "Flatten" the table using sandpaper on a flat surface, are most likely actually producing a slightly convex table. This is due to the fact that a mouthpiece table has a smaller surface area associated with the window. Precautions or extra table "treatments" are advised to insure that when you flatten the table, it is truly flat.
Concavity, when done correctly by hand can insure the best of all worlds. The table concavity started back in the days when natural wood mouthpieces were the norm, and due to their two different axis of thermal expansion (due to grain orientation) and very poor water shedding characteristics, makers applied concavity to ensure that the reed works better with the facing. If the mouthpiece warped, at
least the concavity would help insure that the mouthpiece would either get less concave or flat, but it would have farther to go before it goes convex.
It is generally thought that reeds work well with flat tables or concave, but not with convex tables. This is actually not the case. I have played plenty of mouthpieces that had convex tables that worked okay. The key is that the table must not be too convex, and I have also found that every mouthpiece I have played that was even slightly convex, is improved by flattening the table.
When a mouthpiece is warped, it is generally considered to be convex, and or out of alignment. That is to say that the mouthpiece facing is no longer even and balanced with itself. And also over time, rail tilt can set in, which is a slight inward beveling of the rails (most noticeable near the table). When rail tilt grows too extreme, one can consider this to be a warped facing as well. Generally a warped facing relates to the table, and it is simply diagnosed by how the mouthpiece receives reeds, and responds. However, I have seen many mouthpieces with slight rail tilt that still worked great.
But back to concavity. I have found that slightly concave tables up to the point of a stock Vandoren mouthpiece concavity are ideal, and anything more than that effect resonance, response, and stability in a way that I find ineffective. If a table is too deep, the playing experience can become chewy and lacking in ring, or resonance. The stability of response can suffer as well. But when the concavity is balanced with the facing, and not too deep, wonderful things can happen. The ring remains, but depth sets in, and a wonderful combination of stability and flexibility harmoniously exist. "Instant vibrato" is something that comes to mind. You know when the vibrato is something that happens all by itself. If it comes, celebrate it, but if you impose it, chances are that it sounds contrived. That instant vibrato, that ability to let the inner self, your musicianship happen without interference, that natural singing voice that is a natural part of you, is more easily achieved with a slightly concave table, or a truly flat table.
Brad Behn
http://www.clarinetmouthpiece.com
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Author: alanporter
Date: 2009-06-23 22:05
Brad, thank you very much for that very informative response. It is good to hear from an expert.
Alan
tiaroa@shaw.ca
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Author: Bob Phillips
Date: 2009-06-25 16:11
Caution, Alan!
I had an eBay mpc that played pretty great, so ordered a new one as a back-up. It had a hugely concave table, so I sat about to flatten it. By time I'd done that, i had a useless mouthpiece blank.
Sadly, I was so offended by that big hollow that I never even played it before ruining it forever.
Bob Phillips
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Author: alanporter
Date: 2009-06-25 17:58
Thanks for the caution Bob. However, I bought 8 unused student mouthpieces for $30 (on that website), so even if I ruin the lot it won't be a fortune. The education I will learn will be worth it.
Alan
tiaroa@shaw.ca
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