connloyalist

Not sure where to put this topic, but here goes:

Suppose you have two trumpets, totally identical except one has a standard weight bell and the other has a heavy weight bell.

In these situations it feels to me ("my chops") that the heavy one needs more energy to "get moving". But does the heavy weight bell have more resistance? Are these two different things? The same?

Do you folks who use Warburton backbores use a larger backbore on heavier weight instruments (suggesting more resistance)?

It is my understanding that the resistance of an instrument isn't so much the volume of air you can blow through the thing but the feedback you get from the sound wave (undoubtedly an oversimplification). Does the amount of this feedback change with different bell weight? Different bell alloys?

Regards, Christine

rowuk

I think technically the heavy bell will project more of the energy out of the front of the bell. The lighter bell will vibrate itself and "use up" some of the vibrations in the horn. It will also add those vibration "disturbances" to the sound. In any case, the light bell radiates more of the sound from the outside of the bell. This means less projection, but that you hear yourself better. This is why you think that you need more energy to get the heavy bell moving - you don't hear what is coming out of the horn as well. The heavier horn will be perceived as louder for people in front of it.
Resistance is perceived as many different things. If you take your favorite instrument in a large room with good acoustics, it will seem to play freely. Take that same horn outdoors in an area without houses and trees (like near a lake) and you will get the impression that it has more resistance and that you have to work much harder to play. This is because you don't hear yourself as well. The "resistance" is technically the same.
If you change the thickness and material of the bell-or even the bracing, you will change the amount of sound radiated off of the outside of the bell, thus changing what you hear first, thus changing your perception of resistance.
All of the parts of the trumpet can change the real resistance too. The description "a free blowing instrument" can be interpreted many ways. If in fact it is very free blowing, you may not be able to play long phrases because you run out of air. You need to find that optimal resistance for the playing setting that you use the most.
I would use a very light horn for a marching band so that I could hear myself better, but prefer a very heavy trumpet for orchestral work where the room is acoustically cooperative!
Just changing the bell weight is not enough to get an optimally balanced instrument.

Tootsall

Just to add something to Rowuk's great answer to your question: as trumpet players we generally refer to the amount of "work" we have to do to maintain a good vibration in terms of "overcoming resistance". In fact, we are really overcoming impedance.

In electrical engineering terms, resistance is that which resists the FLOW of an electrical current (DC); impedance is that which resists the oscillation of an electrical current (AC). Virtually all of the elements of a trumpet design have something to do with the IMPEDANCE of that instrument: in other words, it's "willingess" or "resistance" to maintain a good, strong vibration within the air column. Poorly placed braces, different metals, design and condition of valves, even the amount (and location) of annealing of the bell can affect the impedance. Because we have to work harder to maintain the vibration in a high impedance instrument we tend to think we are overcoming "resistance" so that's the term we tend to use. (and let's face it, "resistance" is a more commonly known term than "impedance"!)

We've frequently heard how a "large bore" trumpet really doesn't have that much different a "resistance" than an ML or M bore; the reason is that it doesn't take much more energy to push air through a .464" dia tube than it does through a .460" dia tube. The real question should be "how easy does it support the vibration set up by the player?"

A heavier bell horn will tend to resist allowing the metal to vibrate, thus tending to keep the energy of vibration within the air column (pushing the sound "out front") but also reducing the amount of vibration in the metal of the bell and thus, the sound that the player's ears hear coming off the back side of the bell. This is also why we tend to think of a yellow brass instrument as being "brighter" than one of red brass...it is harder and "rings" more. Consider what's been said about Monette: that they really project to the audience easily.... AND that they are so softly annealed that it isn't recommended that you put them on a trumpet stand because they'll bend easily! IE... they are really efficient and they really project "out front" because they resist the vibration of the metal of the bell.

Check out the studies that Renold Schilke did where he experimented with different bells including lead! (horribly impractical but demonstrating the point). http://www.dallasmusic.org/schilke/B...html#Materials .

Siegtrmpt

I'm not sure if a heavy bell contributes to the tone or saps the energy out of it. It really depends more on what you put into it. I've been looking for a bell that plays with more rhythmic integrity. Anyone know of one?

Richard Oliver

A one, and a two, and a, UGH.

A one, and a two, and a, OINK.

This is a great forum. Where can you find really top notch replies and wit too?

Good to be in your Company,

Richard Oliver

rowuk

Thanks for the clarification Tootsall!
The DC (direct current) of course does not oscillate and would correspond to us just blowing air through the horn without producing a tone - only useful when using the (deburred) spitkey! We get rid of that constant stream very quickly. The AC (alternating current) would be the vibration set up in the horn when actually playing it.

A heavy bell cannot "sap" anything out. Everything contributes to the tone that we hear!

Check out any church on Sunday for bells with rythmic integrity!

connloyalist

Yes, great replies! Very instructive, especially the "resistance" vs "impedance" explanation.

I seem to remember reading somewhere that you really don't need to blow air "through" a trumpet (or any other cup mouthpiece instrument), we just use air flow because without it we can't vibrate our lips. In that same place I seem to have read that the sound waves reflect off the (open?) bell back to your lips and this is experienced as resistance, with only single digits percentage wise coming out as audible sound. Without that reflection/resistance, you can't play because you couldn't maintain a vibration. Meaning the resistance isn't the bore, it is the reflection of the sound waves.

Am I remembering this correctly or getting mixed up?

It seems to me to make some sense, because the narrowest part is the throat of the mouthpiece. Wouldn't the implication then also be, that for example misaligned valves cause resistance not so much by narrowing the bore, but by causing additional reflection of the sound waves. If true, then anything that increases the reflection of the sound waves, adds resistance (tight bends over easy ones, for instance?).

Regards, Christine

Tootsall

Christine: I can't find any fault with your reasoning. I've read the same story as yourself; where smoke was blown into a horn by the player to demonstrate how long it really takes for the volume within the instrument to be completely displaced by the breath. Naturally the throat of the mouthpiece (and the diameter of the venturi in the receiver) is so much smaller than the bore of the tubing in the instrument as to make the tubing size irrelevant in terms of simple resistance to flow. ANYTHING that would tend to damp out the axial vibration of the air column will "add impedance"... whether that be the shape of the bell flare, a poorly placed brace, or a mis-aligned valve.

Remember the stories about the location of a waterkey and how it can affect a particular note? (guys having water keys removed or relocated, some notes that can be played perfectly well with the water key held open while others just "die"?) Because the interruption of the tubing happens to lay "at" a particular node and therefore requires more (or less) energy to keep that note speaking? Simply put, the impedance for that one note is changed or upset.

If you want FLOW... go play a tuba. If you want SOUND, then stick with the trumpet!

wilcox96

Rowuk & Tootsall...

Terrific.

I have certainly experienced this "phenomenon" in recent testing of various trumpets.

I took one of the horns I thought sounded very powerful in the practice room to a big band rehearsal. This was at a college - and the band let me sit in for a number or so. In a section of 5-6 tpts, I had a hard time hearing myself - and I was playing lead. Working noticeably harder to perhaps recreate the "around the player" sound I get on my Bach 72*. At the end of the first tune, I purposefully (though, playing lead...aren't you supposed to..?? hahaa) held the note over just a tad. The sound was wwwwwaaaaaayyyyy across the room! Talk about projection! This is exactly what you guys were talking about.

But how to balance this out? To get the sound around you so you can balance in a section...vs the desired projection. I don't think I have any problem being heard out front...as it is. I do agree that the color of some of the horns I've tried is certainly interesting. But at the expense of losing myself in the section - much less balancing. Now...I will say that I did not test these in a smaller setting. By that, I mean say - 2 trumpets, a bone, french horn, a few woodwinds..etc...like might be found in a pit orchestra. Perhaps this horn (or these horns) might have been just fine in that setting. ??? But then...when playing in a mic, in a pit...what projection am I shooting for? hmmm...

Thinking (typing) out loud...

The real question to you guys is... if you have a horn with all this color and projection...do you just get "used" to that sound in front of you instead of around you, so that you don't work hard trying to hear yourself? Make sense? OR... should it really be about balance around "AND" in front?

Tootsall

Sorry, I had to wait until I got home from work to find this link. If you check it out you'll see that Prof. Moore's credentials are impeccable (which means that they can't be pecked!) Take a look at the link on this page: http://vanadium.rollins.edu/~tmoore/...t_research.htm that reads "Bell Vibrations". Spend some time looking at the pictures, reading the article, and thinking about what he says. When I found this site (it used to be linked through from the GR website) it was one of those "aha!" moments.

As far as Brad's question(s) are concerned, I'd say that you have to get used to your own particular horn. How many times have we heard "it took a while for me to get used to the sound" or "I had to learn to lay back and let the horn do the work"? I think that's exactly what's going on.