What impact does Bore really have ?

Discussion in 'Trumpet Discussion' started by Masterwannabe, Sep 26, 2009.

  1. Dale Proctor

    Dale Proctor Utimate User

    Jul 20, 2006
    Heart of Dixie
    If I understand what you're saying, then a classic short cornet would be just the opposite - the leadpipe/tuning slide assembly is much longer than that of a "normal" trumpet - so the bore should measure larger. That's not really the case, though; corresponding models of cornets and trumpets have the same measurements at the 2nd valve. Maybe that's less than optimum, though...?
  2. beautgrainger147

    beautgrainger147 Pianissimo User

    Aug 6, 2009
    I realise the topic has evolved slightly from the first posts but I wanted to add that my loudest instrument is my small bore conn, I thought it was the quietest from playing in the house but I've taken my trumpets to work for lunchtimes and practiced outside and briefly played in the large buildings. It also has less resistance from the mid range up than my conn cornet and only slightly more than my dutch ML bore trumpet.
    Tonight I'm hoping I'll see one of my friends with a 22B so I can do a comparison but according to conn literature of the time it used the same tapers, bore and material (but possibly with an optional french brass bell on mine) so one presumes that the differences are mainly in the bracing, added weight of the rotary valve and a little bit from the tighter wrap.
    Hopefully I'll find out and edit / add some info here

    (I guess another good comparison of bore size would be between the 22b and 2b)
  3. johnande

    johnande Pianissimo User

    Jun 3, 2009
    western Wyoming
    I will preface this post by acknowledging that I am not an engineer – I have just enough knowledge of mechanics probably to get me in trouble. Please feel free to add, delete or make corrections if substantial errors are found…

    At the risk of adding more to a mute (no pun intended) point, I would submit the following calculations to consider in the argument that a larger bore requires “more air” to fill the tubing of a trumpet. Although this argument is theoretically correct, it is my contention that it is of little (or no) significance when playing. Given the average length of tubing in a Bb trumpet (with valves open) to be approximately 46 inches (1180 mm), calculations of the volume of air necessary to fill the tubing based on small (.450”), medium (.460”) and large (.470”) diameter bores vary so little as to be virtually insignificant. The figures for the volume of air needed to fill the tubing (in cubic inches) are 7.391, 7.724, and 8.063 respectively for small, medium and large bore instruments. Given a lung capacity of about 300 cubic inches in a healthy adult male, a difference of 0.6 cubic inches of air volume between small and large bore instruments would likely be of little consequence.

    As pistons are depressed the total effective length of tubing increases. With all three depressed simultaneously the total length may be increased up to almost 20 inches. As these changes occur, more air is needed to fill the tubing, but differences in air volumes of small, medium and large bores remain small.
  4. EdMann

    EdMann Mezzo Forte User

    Sep 20, 2007
    Los Angeles
    We don't fill a trumpet with air. It's already in there. Bore size can change the nodal points of vibration, tonality and such, but as for resistance, there are too many variables to account for to attribute tight vs. free to bore alone: bell flare and taper, leadpipe, mpc.

    Try the old trick of taking in smoke (of your choice) and blowing through the trpt, Large and small bore and see how long it takes for the smoke to actually come out of the bell while playing. Time it. Same for each. And you'll run out of air before you see it.
    Rinse, lather, repeat.

  5. johnande

    johnande Pianissimo User

    Jun 3, 2009
    western Wyoming
    Ed... thanks for the response. I am afraid you took my use of the phrase "fill the trumpet with air" too literally; I was using this term in the same sense that many of the above posters used it or a similar phrase. I hope most readers interpreted the phrase as I had intended. Re: the old smoke trick, as it is normally performed by individuals, lacks any semblance of validity for three reasons: First, the volume of smoke in the expired air cannot be subjectively controlled, second, the volume and velocity of expired air entering the trumpet per second cannot be adequately controlled, and 3. output criteria (time until smoke exits the bell, volume of smoke, density of smoke???) cannot be adequately measured. However, the smoke trick would be an interesting experiment/test if we had apparatus designed to control the above factors (as well as humidity, temperature and other factors which might also affect the results). My primary point in my initial post was that differences in the volume of air necessary to "fill" the tubes of instruments with different size bores do exist, but those differences are so minimal that they probably have little, if any, impact in playing an instrument. I certainly respect your opinion, but since at this point neither of us have objective evidence to support our opinions, we will just have to agree to disagree. JA
  6. rowuk

    rowuk Moderator Staff Member

    Jun 18, 2006
    If we would only read the material already posted..... (see my sticky thread on how a trumpet works.........)

    I would venture to say that most players have no idea what is really happening in a trumpet (nor in my opinion should they). The amount of air "moving" is what the designer guessed that his customers need to keep from suffocating, but also to have enough resistance to be able to play long phrases. This volume of air does not play directly with pitch or volume per se. Many players indirectly prove this by drilling out the throat of the mouthpiece. The air inhaled is exhausted more quichly, because the horn system is less efficient due to the proportion of throat size to bell size.

    Bore size has NOTHING to do with efficiency. Customers EXPECT large bore instruments to be "free blowing" so the designers generally build them this way.

    In the trumpet there are 2 different types of waves - standing waves (that actually create the sound and slots) and travelling waves that actually escape the horn. Neither has ANY DIRECT RELATIONSHIP with the amount of air expended.

    Bore is a non issue. The playing characteristics of the horn are complex and any marketing attempt to explain them border on extremely ignorant. All of the pieces have to fit together. If one is only aware of one or two facets it is tough to explain anything at all.

    The smoke test IS valid in that you can blow your brains out and it still takes a very long time to "see the smoke". If we truly were moving tons of air, this would occur much more quickly. I would conduct the test in a different way: just blow smoke through the horn without playing - it appears out of the bell in a relatively short time. Then once more while playing - it takes a very LONG time.
  7. Bay Area Brass

    Bay Area Brass Piano User

    Mar 2, 2007
    San Francisco
    I wouldn't say bore is a non-issue, although different players are going to have a different take on the subject , based on personal experience and style of play.

    I play a medium bore Committee Deluxe now, previously playing a large bore Committee Deluxe of the same era. For me, there was a big difference in tone and feel between the two horns. Since they were the same model and same year, the only difference was bore size (I've owned two horns of medium bore and also 2 large bore Committees). Before that, I've played a .470 Mic Gillette Martin and a .484 Mic Gillette Martin.

    That being said, bore is only one factor of many, and it's hard to compare how they differ when comparing horns of different models or makes, for example at medium Committee and a medium bore Bach. and a Connstellation 38B has a feel that is unique to itself.
  8. a marching trumpet

    a marching trumpet Mezzo Piano User

    Feb 11, 2009
    Murfreesboro, TN
    Well I don't want to read all of this stuff before me so here's my personal experience.
    I have a bach Strad Model 37 (1976) and you know everything is standard nothin fancy or custom
    I played one of my friends Schilke's and I can't remember the bore but it was a bit smaller than mine and it had a reverse leadpipe which from what I remember, It was a heck of alot easier to pop high notes out and I could blow less air to get what I wanted in the upper register, but I do recall when he picked mine up he no longer had a Double C like he did on his schilke. I remember that our both resonated very similarly (almost exactly) but his had more of a cutting brightness, while mine had a darker tone to it. I believe our bell material differed a little :dontknow: Anyways that's my experience my sophmore year at high school (other guy was a freshman).
  9. Brekelefuw

    Brekelefuw Fortissimo User

    Mar 21, 2006
    Your first statement is pretty ignorant.
    You list of a bunch of differences in the way those two horns play, but none of them can be attributed directly to bore size. The reverse leadpipe changes the bracing design on a horn, and the bracing design has an incredible effect on the way a horn plays. This effect is very noticeable if you have the time to sit down with someone who can solder and move the braces for you.
  10. rowuk

    rowuk Moderator Staff Member

    Jun 18, 2006
    Bore size is simply boring. Those who know, know better, those who think they know confuse others and those that don't know, don't know who to believe.

    The bore is a useless parameter for any players decisions. The only parameter that counts to the uninitiated is: is it shiny enough. Once we are beyond that, the only important parameter is does it play well enough. All of the other stuff is just there to confuse the uninitiated.

    The make of tires on an automobile will tell you nothing about how fast it goes. 300 HP is only significant if you know that you are talking about a Corvette, tractor or tank.

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