Measurements of trumpet bore along entire length

Discussion in 'Trumpet Discussion' started by gordonfurr1, Jan 20, 2015.

  1. gordonfurr1

    gordonfurr1 Forte User

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    Yes!

    That is what remembered seeing! Thank you. Now, I wish it was the whole length of the main pathway.
    Ah well...K am going to do something entirely weird anyway...
    A completely folded in horn with zero space between passages and no valves...a few well-placed holes to trigger a change in the standing wave.
    I figure if I could play my school fight song on a conch shell using my hand in the bell...then I could probably drill enough holes to make SOMETHING happen.
     
  2. gordonfurr1

    gordonfurr1 Forte User

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    Well, using the exhaust analogy again, I was looking over concepts for minimizing reversion and spotted these images. The timing of the pulses in a trumpet is MUCH more problematic to optimize reversion since there are SO MANY variables (pitch, pipe length, pressure variances ppppp-FFFFFFF, etc) that perhaps just MINIMIZING reversion is maybe the best tactic to improve the instrument's natural capability (the PLAYER is always the most important element)...

    https://www.google.com/search?tbm=i...ion&ei=vqTLVODbFtb_yQS--IKAAg&ved=0CAkQ9C8wAA


    So, to that end a gentle swale or flare might be useful.

    I remember back in the seventies discussing racing sailboat hull design with my engineering college roommate, and we both were intrigued at the notion of building into the design of the hull a swale just aft of the bow to effect a reduction in the breadth of the bow wave..thus changing the ration of bow wave width relative to bow wave length. For a given wetted surface area, a LONGER bow wave relative to bow width is desirable...or so at least we assumed.

    This phenomenon is somewhat associated with the same physics we are encountering with trumpet design and exhaust design.

    So, in the back of my mind I was envisioning:

    1. A bell design wherein the bell throat was cut, and a slightly larger bell throat and bell flare slipped over...even possibly leaving a small airspace exposed around the edge. A side benefit would be what reversion wave was generated by the flare opening, much of it would revert back to the PLAYER'S EAR OUTSIDE the bore of the instrument instead of going entirely back THROUGH the bore back to the player's lips.

    2. A gentle swale (enlargement or shrinking) of the diameter of the bell tube maybe about five inches before the bell flare.
    Thoughts? Got any trumpets you want to chop up and see?
     
  3. rowuk

    rowuk Moderator Staff Member

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    Don't forget, there are three principles being applied: the resonance of an irregular shape is based on volume, the resonance of a tube is based on length, and the resonance of a horn is based on horn theory. In addition, the leakage of the standing wave depends on the inertness of the instrument walls due to material, thickness and bracing. There is an artisan in Switzerland that disassembles Bach trumpets and puts them back together like a precision swiss watch. No change of parts or bore but dramatically improved response.
     
  4. gordonfurr1

    gordonfurr1 Forte User

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    VERY good comment, Rowuk. I have been studying (odd subject) the ocarina. Volume.
    Plus, the leakage of the wave energy through the walls is something that has been on my mind after watching Jason's video on SWE.
    I wonder if it tends to make a horn sound "dead" by dampening some delicate overtones due to the higher (but well-placed) mass still being somewhat absorptive, but suppose in theory it should not.

    I'd like to read about that artisan in Switzerland. I shall Google.
     
  5. SteveRicks

    SteveRicks Fortissimo User

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    There is also a fellow here in the US that does similar. You would think the Bach Co. would try to learn from this practice. It is much more difficult and expensive to disassemble and then reassemble a horn. Why not do it on the front end when the horn is being made? If people are willing to pay for the disassembly and reassembly on top of the initial price of the Bach, it seems to make sales sense (and cents) to do so when the horn is constructed. You increase your pool willing to purchase Bach's to include those that were avoiding them due to the initial construction with just a small increase in cost. And, you are turning out a better playing product-which is what people are hunting..
     
  6. rowuk

    rowuk Moderator Staff Member

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  7. gordonfurr1

    gordonfurr1 Forte User

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    One would think Bach WOULD at least form a specialty shop for this.
     
  8. rowuk

    rowuk Moderator Staff Member

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    It is amazing what Bach does not have time for..........
     
  9. gordonfurr1

    gordonfurr1 Forte User

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    What is more responsive...
    A battleship or a PT boat?

    The battleship does big tasks reasonably well.
    The PT boat takes care of crumbs extremely well.
    Neither does well what the other can, nor really could it ever.
     
  10. stumac

    stumac Fortissimo User

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    Are you comparing a trumpet with a tuba?:D

    Courtois had a bell over bell design a few years ago, I have only seen one, did not play it, the design has been discontinued.

    To dismantle, do the necessary tweaks and reassemble for a craftsman there would be nearly a days work, to improve practices on a production line would mean a substantial increase in unit cost. While the product is selling in sufficient quantity to keep management happy there is little incentive to improve.

    I am not knocking Bach, they are fine instruments.

    Regards, Stuart.
     

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