Can resistance be heard?

[LeMark]

Let's say you have a tuba feels like the air isn't flowing through it unrestricted. Call it "feedback" or "resistance" or in extreme cases "stuffiness" but is that more of a factor for the player, or can the audience hear it?

And in any way is a little feedback a good thing?

[Dents Be Gone!]

I agree, guys. This is the way to go.

[bort2.0]

Some tubas can have a very "hollow" sound to them. I played a kaiser Cerveny once that was so resonant, I thought it was going to shake itself apart. When I heard it from a distance, "hollow" was the best way I could think to describe it. Hated that particular tuba.

Otherwise, as DBG mentioned, I think the effects of resistance on the player can be noticed. Or, some players are really adaptable and just sound the same no matter what. Not sure that's me, though! :)

[bone-a-phone]

Sorry I keep answering tuba questions in terms of trombone, but it seems relevant...

Some players have internal resistance and some need external resistance applied. They gravitate toward opposite type instruments. An internal resistance player finds many horns stuffy.

I definitely think if a person is on the wrong kind of horn, you can hear the imbalance. I'm not sure you can hear resistance directly, not sue what it would sound like. They will overblow or can't fill the horn or breathe too frequently - phrasing suffers.

I play a trombone with small valves, so it has its own resistance. I have a buddy who likes horns that are wide open - axial valves. When he plays a small horn, he thinks it's stuffy. When I play a horn that initially seems stuffy, I just back off, and it instantly behaves better.

To me, tubas are all too wide open. I have a very hard time controlling the air. I'm likely to pass out from hyperventilating when playing tuba. You might be able to hear that in my articulations, which are way too hard.

So maybe you can hear the resistance, but only indirectly through the player's foibles.

[Stryk]

Harvey Phillips said he preferred a good bit of "Subtle resistance".

[bloke]

To me, the generic type of tuba that Mr Phillips played is what I would rate as je ne sais quoi to the extreme.

[UncleBeer]

I know that efficiency can be objectively measured. I've mentioned here before my use of a software/hardware package called the Brass Instrument Analysis System. One component of the package is the "pulse response window" which works similarly to SONAR, receiving echos of a BIAS-generated pulse sent through the instrument. If there are early reflections (bad porting, blobs of solder, leaks, etc.) this will show in the results.

Below are results from a client who could not explain the sudden change in playing characteristic of his MW-2145: there was a range of about a third near the top of the staff which were now unuseable. BIAS showed there was something significant going on about 320cm from the mouthpiece along the windway. After sending a series of dent barrels through the instrument, I was able to coax out a piece of shelf liner which the client has somehow gotten up into the top bow of his horn. Problem solved! The blue reading is the 'before' reading, and the red reading is after I'd removed the shelf liner.

2 2145 shelf liner blue before, red after.jpg (138.68 KiB) Viewed 15259 times

Another interesting reading is the PRF window at the bottom, which shows the percentage of acoustic energy input which is being reflected back from the bell (aka: "efficiency). The reflected energy is a good thing, as that's how standing waves are generated inside a brass instrument. Higher PRF numbers are better.

BIAS will also objectively show intonation characteristics, and another component will do physical modelling, allowing builders to predict the characteristics of a hypothetical instrument. Amazing stuff. (I'd proposed a talk on BIAS at the recent ITEC, but was rejected. Maybe not 'amazing' enough ).

[matt g]

(I'd proposed a talk on BIAS at the recent ITEC, but was rejected. Maybe not 'amazing' enough ).

The ASA (Acoustical Society of America) would’ve likely accepted that presentation.

“A day in the life of a repair person using computational measurements and tools” would be a pretty interesting lecture in a special session.

[bloke]

My guess is that most of the accepted lectures are truncated versions of theses and dissertations on "How It Feels To Be" this, that, and the other.

[arpthark]

interesting stuff

How do you use the BIAS system with an instrument? Is it something that you attach while the player is playing, or does it use mics, a stand-alone system, etc.?

[MN_TimTuba]

It's a device that fits the leadpipe a d sends a signal through the instrument. No player is involved

[UncleBeer]

How do you use the BIAS system with an instrument? Is it something that you attach while the player is playing, or does it use mics, a stand-alone system, etc.?

The head is a transducer, containing both speaker and microphone; the head accepts all brass instrument mouthpieces with only the shank protruding so that it can be inserted into the instrument. A USB cable attaches the head to any Windows computer. The software sends a sweep tone (all the audible frequencies) through the instrument, and records and charts the response sent back from the bell (or actually, a little past the bell, where the acoustic end of the instrument actually is, due to the "end effect").

A ton more info available at the BIAS site, including the instruction manuals. https://www.artim.at/en/

[Dents Be Gone!]

I agree, guys. This is the way to go.

[bloke]

It never particularly surprises me when children (up to age 25 or so) end up with valve oil bottles stuck in their French horns, and probably most of them didn't intentionally stick them in there but they found their way in there via not being secured in the cases, but what causes me to roll my eyes is adults - perhaps 26 years old and older - who intentionally store stuff inside their tubas, thinking that nothing can possibly happen.

Your example is one, and a common one that I've seen has been tuba stands - which put nice outward dents in their instruments' bells, and - of course - sheet sheet music, as well as other things. Rags - or mouthpieces wrapped in rags - end up on the wrong side of the bottom bow. Some people think it's clever to store their mute in their tuba, because the bag is able to zip over the top of the mute in some instances. When the tuba slides forward or sideways in a vehicle and the mute's top (in the barely padded bag) hits the back of a seat or the side of a seat, people bring me their $10,000+ instruments and ask me to remove three or four rectangular outies from their bells... then there are the people who decide to walk across ice with tubas on their backs, etc...

[Dents Be Gone!]

I agree, guys. This is the way to go.

[bloke]

I bought a 19-in bell English compensating E-flat off of eBay from a well-known and widely well-liked tuba player. When it was time to pay, they sent me a personel note warning me that it was not a particularly good one, and that I could back out. I told them I wasn't worried - as long as the valves were okay, and - when I got it - all I did was clean a fairly significant layer of lime out of the inside of it, and it played great...

I don't buy into the water key nipple and tiny dent stuff very much at all, but I think even a fourth of a millimeter of scale all the way through a valve section can probably degrade a very fine instrument to only an okay one.

======

I attended someone's doctoral recital where they played a beautiful silver-plated B&S pt-10 F tuba. They didn't play badly, but it wasn't wonderful. They actually didn't pass, and they were not awarded tenure at another University where they were currently hired to teach, and lost their job.

After that recital - which was too damn late, their teacher sent them to me to see what might be wrong with the instrument, as their teacher finally played the instrument themselves and found out that they couldn't play it either. The entire valve section was coated with a 1/8 inch thick layer of sort of soft lime deposits, which were crumbly. It wasn't slime, but actually lime/scale. Nevertheless, it was disgusting, and do the math and you will realize that the bore of the entire valve section was reduced by a fourth of an inch, and the area of the bore was reduced by an incredible percentage. Once I completely cleaned it, it was just about the best pt-10 that I had ever played. What a shame for that person, who was working their butt off to try to make that instrument go for them - and lost their job.

[bort2.0]

My guess is that most of the accepted lectures are truncated versions of theses and dissertations on "How It Feels To Be" this, that, and the other.

UB's stuff was clearly too sciencey.

I bet that committee would have had far different hopes and expectations when seeing the words "bias" and "resistance."

[hrender]

BIAS will also objectively show intonation characteristics, and another component will do physical modelling, allowing builders to predict the characteristics of a hypothetical instrument. Amazing stuff. (I'd proposed a talk on BIAS at the recent ITEC, but was rejected. Maybe not 'amazing' enough ).

This sounds like an amazingly useful tool for players, builders, and repair people. I'm surprised (but possibly shouldn't be) that a talk on it was rejected.

[bloke]

To the original question, it's difficult to imagine a listener being able to hear what a player feels, particularly if what the player is doing is done well. Note that I said "hear" and not "see".

I believe a great deal of what people claim to hear are things that people see, as so much of what humans rely on is their sight.

[UncleBeer]

This sounds like an amazingly useful tool for players, builders, and repair people. I'm surprised (but possibly shouldn't be) that a talk on it was rejected.

Perhaps other factors were at play.