TubeNet

Yes - manufacturers, listen up! The resistance should be "just right"! I don't want to hear any more excuses!

They could, of course, find all the consultants they need here . . .

It sounds like you did some major work on your instrument over the summer when you did not play. This also sounds like you had a major change in the way the horn plays. I suspect the two are related.

Did you unsolder anything? If so, you may have resoldered and not closed the tubing. New horns have this, the most well known maker of bass trombones regularly sends out new instruments with ferrules unsoldered in the valve tubing.

Bottom line, nobody can tell what's wrong with your horn over tubenet. I'm sorry, it's true. You need to get to someone who knows what they are doing and get real help. I suggest a repair tech or a person who plays tuba for a living.

Never really experienced a horn being too free blowing.
Have played some old large leaky monsters that seems to suck the air out of you, but as for "free blowing", I've always looked at that as a good thing

When I had my Mphone 184 CC, I thought gee I could get a bigger sound with a bigger tuba. So I play-tested a Rudy 3/4 CC, with shipping from across the country. Also a 188; they both were just too big for me. The Rudy in particular sucked the air out of my lungs, and I wasn't getting much sound out of the 188. My MW 182 F was almost as easy to play as my (french) horn, which of course is more resistant than any tuba out there. So I learned that whatever I play, it works better with resistance. My NStar in the picture (that looks almost like a BAT on me,) is just damn near perfect, but becomes less and less perfect the bigger backbore I try. So I stick with my PT64S, having tried everything else under the sun and had none of it work as well.

Balance is the key!
I've had a few large instruments in my time. Some well balanced some too open some too resistant.
The B&H Bb is one of the stuffy ones. great for playing quietly but not that good for loud.
Melton Fafner, far too open for me. Just too in efficient with the air.
I now have (and sell) the New Cerveny 693 6/4 BBb. And I must say the more I play it the more impressed I am!
It whispers beautifully and if you are strong enough it has a sound like dropping a depth charge! The articulation is really sweet too.
I've seen threads where people have taken large Cerveny Tubas and swapped out the valves for BIGGER bore. I'm not sure that's the best idea.
Bigger is not always best!

I was really impressed by the 793 (same but red brass). For a huge horn, it really has good, balanced resistance and is easy to control. Great intonation and dark tone.

What musicians refer to as "resistance" is very important to the function of a brass wind instrument. Engineers work with impedance which is a combination of factors which result in what we refer to as "feel". As mentioned, the easist way to balance this is through use of an appropriate mouthpiece.

As for the "B & S" "Big-Valve" piston set, I was responsible for this at the time the new production facilities were being built up in Markneukirchen. We started with a valve bore of 19.00 Mm, very close to famous York "750 bore". Many "B & S" and now "Melton Meinl-Weston" piston valve sections use 19.00 Mm for the first three and 20.00 Mm for the fourth valve. Since then other bores have been added, smaller depending on the instruments for which they are used.

Resistance is not something determined solely by the mouthpiece or valve bore. This is determined by the instrument as a complete entity. Instruments for beginners have quite a lot of resistance. This makes them easy to play but limits dynamic range. Instruments for advanced playes and professionals are engineered to have a strong fundamental component, maximum dynamic range and efficiency over several octaves. One has only to look and listen to see what fine artists are using to achieve the remarkable results for which they are noted. The rule of thumb is "large instrument - smaller mouthpiece" and "small instrument - larger mouthpiece". There are many fine mouthpieces available so that the "resistance challenge" can be quickly rectified.

Over the years I have been responsible for the manufacture of thousands of tuba mouthpieces. Without extensive discussion I can only say that sound quality, resonance and dynamic range come first. If those factors are positive and with good breathing and tone production on the part of the player, what we refer to as "resistance" is not too significant. Reducing throat bore or tightening a backbore does not always relate directly to more. Changing such dimensions can have adverse effects on sound quality and intonation. As with the game of Chess, one moves can affect many others; much prudence based on experience is necessary.

Best bet for anyone is simply borrow and play as many mouthpieces as possible. The ones with which the most music can be made will come out on top.

Bob Tucci

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OK, what would that device measure? Acoustic impedance?

Consider the opening to a duct. The acoustic impedance at that opening is the ratio of the acoustic pressure at the entry to the duct, to the volume flow of fluid into it. Like electrical impedance, acoustic impedance may be a strong function of frequency.

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