Selecting Blokepiece System = Selecting Edelbrock System

[iiipopes]

Yes, I am getting off the wall here. Bear with me. Forty years of experimenting anecdotally bear this analogy out.

The Blokepiece system for tubas is the same as the Edelbrock system for small block automobile motors. A player can tune in exactly what is required to get the best out of any player, tuba, and repertoire combination. Here's why.

Despite some nay-sayers, I still maintain that a brass instrument mouthpiece functions essentially the same as a carburetor, analyzed from the application of the Bernoulli principal: as a fluid (air is a fluid) increases in velocity, it decreases in pressure, and vice-versa. This is the fundamental concept behind why a carburetor works, and why an embouchure actually works, and, as each player has a different capacity, diaphragm and intercostal musculature, and mandibular geometry and embouchure, it has a great bearing on how each of us play our respective instruments.

When I was a boy and young man, like all red-blooded American boys, I read about how to hot-rod cars. I even got an Edelbrock catalog/manual. Two things struck me immediately: 1) you had to match the carburetor and intake manifold to the size of the engine and the rev range of operation, and 2) the thickness of the spacer between the carburetor and the manifold was the primary indicator of throttle response, irrespective of the horsepower desired.

OK. Now, decades later, I applied these principals to tuba mouthpieces: 1) a player's vital capacity determines how large a throat bore a player can utilize efficiently (how large a carburetor can be matched to the horn). Bloke got it right empirically that a Q bit (.323) functions best with the majority of players that have a moderate vital capacity, in the same way that a Holly or Edelbrock 650 cfm works best with a Performer manifold for off-idle to 5000 rpm street range performance on a 327-350-383 small block.

The next factor is the spacer. According to the Edelbrock catalog, the thicker the spacer between the carburetor and the manifold, the better the gas mileage and efficiency due to the increase in runner length that keeps the fuel in suspension better due to higher velocity of the mixture ahead of the manifold. But, beyond a certain point, there is throttle lag waiting for the mixture to flow, and the car can hesitate from momentary lean out as the accelerator pump tries to keep up. Conversely, the thinner the spacer, the better response and with the increased flow the higher the horsepower at high rpm, but at the increased risk of inefficiency of the mixture separating out at low rpm, causing manifold puddles and stutters.

So, with my Imperial with its .323 - 8.2mm bore, that is a match to my vital capacity, after experimentation with various mouthpieces, from less than 8mm to more than 8.4. Having that determined, I bought a couple of spacers. After I experimented with screwing the rim in and out to see at what point I had the best balance of low range breadth (torque) with good articulation (throttle response) and high-end smoothness (horespower), for me I determined that a bloke spacer trimmed to .080 gave me the best balance of tone (torque), articulation (throttle response) and dynamic range (horsepower).

So I took one of bloke's spacers, sanded it down on my bench by rubbing it against a flat piece of sandpaper to that thickness, then installed it as the gap between the rim and the cup. Indeed, for me, it gave the best response for my vital capacity, my embouchure, and my playing style with my instrument and repertoire I play in my ensembles.

Just as all custom engine builders can tune a carburetor/manifold/block/cam/compression/timing/exhaust to the driver to deliver a desired driving characteristic in the particular automobile, I have tuned a 2-piece Imperial with a modified spacer and lexan 32.6 Modified Helleberg rim to my Bessophone to my embouchure, vital capacity, and repertoire, where I don't have to think about it: I just play. No mess, no fuss, no muss. I just play. Everything responds as it should, and even if I have to be away from the horn playing another brass instrument, when I come back, it is there. No excuses.

I encourage everyone to experiment with these variables in a controlled manner, as I did: find a basic model that works so that you can fine tune the details, instead of a "shotgun" "safari" approach.

Bloke, thanks again!

[Robert Tucci]

The Information posted is interesting. We work with air in motion and resistance. The German term for resistance is "Scheinwiederstand". That translates to "apparent resistance". Aside from someone with huge lungs pushing immense quantities of air toward a low register note with many valves down, factual resistance to the air stream is not a major factor. The resistance we experience and use to our advantage is acoustical. My background also includes much experience with carbureted engines as well and the study of electrical properties. In particular, to aquire an Advanced Class Amateur Radio Operator's license many years ago. Dave Monette has similar interests and discusses oscillating systems and standing waves along with his other remarks on brass wind instruments and mouthpieces. The function of brass wind instruments is very complicated, essentially an area for physicists. There is a rather fine article available (in German), published in "200 Years of Valve Brass Music" (Nicolai Verlag - Berlin).

Internal combustion engine breathing also deals with air flow and harmonics: switched-length intake manifolds are used, to obtain preferable harmonic energy at related engine speed and load conditions. There is one major difference: with engines and at least for high-perfomance, the objective is to get as much air (and fuel mixture) into the combustion chamber. With brass winds our objectives include Efficiency. The remarks presented are of interest: the way the system works is based on acoustics. Getting that right,with mouthpieces in my case, is a primary objective.

Bob Tucci

[Robert Tucci]

The Information posted is interesting. We work with air in motion and resistance. The German term for resistance is "Scheinwiederstand". That translates to "apparent resistance". Aside from someone with huge lungs pushing immense quantities of air toward a low register note with many valves down, factual resistance to the air stream is not a major factor. The resistance we experience and use to our advantage is acoustical. My background also includes much experience with carbureted engines as well and the study of electrical properties. In particular, to aquire an Advanced Class Amateur Radio Operator's license many years ago. Dave Monette has similar interests and discusses oscillating systems and standing waves along with his other remarks on brass wind instruments and mouthpieces. The function of brass wind instruments is very complicated, essentially an area for physicists. There is a rather fine article available (in German), published in "200 Years of Valve Brass Music" (Nicolai Verlag - Berlin).

Internal combustion engine breathing also deals with air flow and harmonics: switched-length intake manifolds are used, to obtain preferable harmonic energy at related engine speed and load conditions. There is one major difference: with engines and at least for high-perfomance, the objective is to get as much air (and fuel mixture) into the combustion chamber. With brass winds our objectives include Efficiency. The remarks presented are of interest: the way the system works is based on acoustics. Getting that right,with mouthpieces in my case, is a primary objective.

Bob Tucci

[iiipopes]

The Information posted is interesting. We work with air in motion and resistance. The German term for resistance is "Scheinwiederstand". That translates to "apparent resistance". Aside from someone with huge lungs pushing immense quantities of air toward a low register note with many valves down, factual resistance to the air stream is not a major factor. The resistance we experience and use to our advantage is acoustical. My background also includes much experience with carbureted engines as well and the study of electrical properties. In particular, to aquire an Advanced Class Amateur Radio Operator's license many years ago. Dave Monette has similar interests and discusses oscillating systems and standing waves along with his other remarks on brass wind instruments and mouthpieces. The function of brass wind instruments is very complicated, essentially an area for physicists. There is a rather fine article available (in German), published in "200 Years of Valve Brass Music" (Nicolai Verlag - Berlin).

Internal combustion engine breathing also deals with air flow and harmonics: switched-length intake manifolds are used, to obtain preferable harmonic energy at related engine speed and load conditions. There is one major difference: with engines and at least for high-perfomance, the objective is to get as much air (and fuel mixture) into the combustion chamber. With brass winds our objectives include Efficiency. The remarks presented are of interest: the way the system works is based on acoustics. Getting that right,with mouthpieces in my case, is a primary objective.

Bob Tucci

Mr. Tucci, thanks for your post. I will have to check out the article you refer to. Thanks again.