More dances with mouthpieces...

[kymarto]

Since I have now three Stowasser mpcs, I am playing with various configurations, throat sizes, etc. Here is something that might be of interest:

The nominal size of the throat on all these mpcs was the same as the top of the instrument: ~10 mm. I opened the throat of one to ~11 mm and that made it more free-blowing with slightly more "presence", but it also made the top notes sharper. I glued a thin reducing ring at the bottom of the throat, with an opening of 9 mm. This has made the sound a bit more rounded, which I like, and also has the nice effect of lowering the top notes: from fingered A upwards. If you are having trouble with a sharp top end, this is a sure-fire way to flatten those notes. Since my spacer was quite thin (2 mm) it does not much change the mpc position for correct tuning. You can put such a thing in temporarily with rubber cement or whatever to check if it works for you.

Note however that if you are in tune with the mpc pushed completely in--you will no longer be able to do so after you insert the spacer (obviously). My instrument tunes with the mpcs pulled out by about 5 mm, so for me it isn't a problem.

I found this a much better solution than trying a thicker spacer to make the mpc longer, as described in my last post. This has darkened the sound, but it is much more effective in bringing down only the topmost notes.

[Gheorghe]

Since I have now three Stowasser mpcs, I am playing with various configurations, throat sizes, etc. Here is something that might be of interest:

The nominal size of the throat on all these mpcs was the same as the top of the instrument: ~10 mm. I opened the throat of one to ~11 mm and that made it more free-blowing with slightly more "presence", but it also made the top notes sharper.

Makes sense to me, since at that point, the mpc throat is more or less an extension of the top joint - and in my case, opening it up slightly raised my top octave (which is what I needed).

Thanks for experimenting!

George

[kymarto]

There are two conditions that affect intonation with the mpc acoustically: The internal volume has to be correct, (to mimic the missing top part of the cone). That is varied by the position of the mpc--pull it out and the volume is increased, and vice-versa.

But the resonant frequency of the air in the mpc is also important--the mpc is a kind of Helmholtz resonator (like blowing across the top of a bottle). A Hh resonator has three parts: a volume, a port and an opening--that determine the frequency. If you make the opening smaller, it lowers the frequency. That Hh frequency affects notes in the air column in its neighborhood--in this case the upper notes of the second octave.

[jbtsax]

Fascinating subject. I plan to remove a portion of the baffle in my tarogato mouthpiece in an effort to darken the sound and to lower the pitch. After the instrument is warmed up, the mouthpiece has to be pulled out about 1/4" to play at A = 440.

[kymarto]

1/4" is about the same as my Stowasser. I already took down the baffle on that mpc a bit, but I think the beak is a bit thin to make major alterations. You should keep an eye out for an old Stowasser mpc on eBay--two just sold for ~$100 each. They are much to closed, about .40", but are easy to open to .65 or .70 and then play well with a nice dark sound.

[Gandalfe]

I know it's mostly about me (not pushing enough air) but I really need to see a mouthpiece expert for my tenor. I'm very happy with my sound on the sop, alto, and bari. So when youse guys talk apertures, baffles, notches, and the like, I think I should pay more attention. I really have no excuse as the mouthpiece genius, Bob Carpenter, likes in the next berg over from mine.