Mouthpiece Gap

Discussion in 'Mouthpieces / Mutes / Other' started by maine trumpeter, Apr 7, 2007.

  1. maine trumpeter

    maine trumpeter Pianissimo User

    Aug 17, 2006
    Does any one know what the proper mouthpiece gap is in the mouthpiece receiver on a trumpet? And does it matter what brand trumpet?
    Thanks Brian
  2. JJMDestino

    JJMDestino New Friend

    Sep 7, 2005
  3. screamingmorris

    screamingmorris Mezzo Forte User

    Apr 4, 2007
    Below is what I read 35 years ago as written by the famous Renold Schilke and as is included in the Schilke mouthpiece pamphlets.
    He said that there should be no gap at all, that the end of the mouthpiece shank should butt against the end of the leadpipe inside the mouthpiece receiver.

    On the other hand, other experts on the Internet state that there *should* be a gap and they state exactly what it should be.

    I would like to know the reasoning behind the claim that there *should* be a gap in that place in the mouthpiece receiver.

    -------begin quote-------



    Two serious shortcomings are often overlooked by both teachers and players of brass instruments. The first is when a mouth piece shank is a bit too large: a gap will exist between the end of the mouthpiece and the inside of the tubing, the mouthpipe as illustrated here.


    When a nodal point of a vibration (sound) hits this gap or depression the result is the same as if the mouthpipe had a sudden bulge. Since the most crucial pail of any brass instrument is the mouth piece followed by the mouthpipe. one can see the seriousness when the mouthpiece does not butt against the end of the mouthpipe. This shortcoming can be corrected by turning down the shank a bit on a lathe. One should remember that when a mouth piece is further in the mouthpipe that the pitch of the instrument is raised, this requires pulling the tuning slide a bit.
    Equally serious is the opposite of the foregoing, namely when the end of the mouthpiece is too small and goes inside of the mouthpipe. This can happen if the foregoing fault is over-corrected by turning down the shank too much. Both faults just mentioned are serious and occur frequently on all brass instruments. If you are a discriminating teacher, player, or music merchant, it is most desirable that a particular mouthpiece fit the instrument EXACTLY.

    quoted from
    also at
    Selecting a Mouthpiece

    ----------------end quote----------------

    - morris
  4. Tootsall

    Tootsall Fortissimo User

    Oct 25, 2003
    Yee HAW!
    A gap tends, (for me, YMMV) to help "lock in" the notes. I have a Schilke trumpet and I once tried a Schilke mouthpiece on it; the notes were all over the map (although I'll admit that I did NOT check to see what the gap "might" be).

    There is no magic number for a gap: it's what works best for YOU with YOUR HORN, it's particular leadpipe and veturi, on the mouthpiece YOU play that has a particular throat/backbore/shank taper.

    For what it's worth I "dialed" in my "numbers" using a dealers' Warburton kit and found that I liked an open horn but with a slightly larger gap (the "B" shank). Once that was done it was "translated" into a GR and I've been a happy camper for 3 years. If I were to change trumpet brands I'd probably have to start "adjusting" all over again but with an Eclipse and a Schilke I don't think that's going to happen any time soon.
  5. screamingmorris

    screamingmorris Mezzo Forte User

    Apr 4, 2007
    Back in the 1980's I studied for certification as a broadcast technician.
    The physics of a sound wave passing through a mouthpiece receiver might be similar to the physics of a radio wave passing through a wave guide.

    If a crack in the street is only half an inch wide, your car tire doesn't notice the crack and passes right over it as if it weren't even there.
    If the crack in the street is bigger, such as 12 inches wide, then your car tire does indeed notice the crack and you feel a huge thump when you pass over that crack.
    The determining factor is the size of the crack in the street relative to the size of your car tire.

    Likewise, if the gap in your mouthpiece receiver is small and if you are playing a low note (i.e. long wavelength) then your sound wave should probably pass right over that gap as though it is not even there.
    But if that gap is much bigger and / or the note you are playing is a higher frequency (i.e. shorter wavelength) then your sound wave definitely *would* notice the gap, the short sound wavelength would "fall" into that gap as it passes through.

    I have not looked into it to find out what note on the scale would correspond to a wavelength that would fall into a specific size gap, but I don't think the math would be difficult.

    So I *theorize* that best gap size would mean the maximum gap size that your range of notes would be able to pass over without falling into that gap.
    The higher your range, the shorter the sound's wavelength and thus the smaller the gap that you would want to allow to prevent the sound waves from falling into that gap.

    If anyone proposes that a gap actually *helps* in some way, I would be interested to find out why / how.
    I'm not dismissing such a possibility.
    I'm just saying that I'm willing to learn.

    - morris
  6. Brekelefuw

    Brekelefuw Fortissimo User

    Mar 21, 2006
    I am renting a Courtois Evolution IV C trumpet right now and it has an adjustable gap. I can hardly make the horn play with no gap. I find a gap of about 1/2cm is best on that horn.
  7. rowuk

    rowuk Moderator Staff Member

    Jun 18, 2006
    Gap like any of the other thousand factors in trumpet design is part of a complete working system. You can design a specific horn/mouthpiece combination to have a lot or even no gap.
    I used to play a Bach 72* with a Schilke 18 and no gap- Schilke cut it down for me. No intonation, slotting or sound problems. I then switched to Monette mouthpieces and immediately had a substantial gap (I don't remember how much it was in 1997). No intonation, slotting or sound problems either. Then my Monette Ajna2 came and it also had a "gap". still no problems.
    Before gap becomes an issue in ones playing, many other things need to be solved first - like body use and breathing. Then your playing is reliable enough to figure out if the difference is "better" or just "different"!
    I have not adjusted the gap on any of my horns since that Schilke experiment in the late 70s.
  8. Old Bugle Boy

    Old Bugle Boy Pianissimo User

    Jan 8, 2015
    North Yorkshire
    Reading this old thread about mouthpiece gap and out of curiosity I did some rough measurements - not that it's likely to matter much, if any, to an absolute beginner like me who can only just about tell one end of a trumpet from the other. The gaps on three of my horns with my favourite Yamaha mouthpieces, are around an eight of an inch. Surprisingly though I found that the gap on my best trumpet, the French Besson, is about half an inch! One day, when I get experienced enough to discern any effect this may have, I might look into doing something about it.
  9. Sethoflagos

    Sethoflagos Utimate User

    Aug 7, 2013
    Lagos, Nigeria
    Interesting subject, isn't it.

    There's loads of these threads kicking about the site, and none that I have seen that reach any consensus conclusion.

    Precious few even mention the height of the gap (as opposed to the width) which I would have thought would be at least as critical; or whether the height varied at either end of the gap. Indeed since no joint is perfect, even those who claim not to have a gap will (if there is a joint) have a discontinuity of surface at the junction of shank and leadpipe that acts as a gap.

    My scant understanding of horn theory hints that the width and height of the gap may have opposing effects, in which case fine tuning of the gap would be based on balancing perhaps the ratio of gap width to height rather than on one single dimensional measurement.

    On the other hand, I don't think Mendez or Dokshizer worried too much about gap. And just now I'm happy to follow their lead.
  10. Old Bugle Boy

    Old Bugle Boy Pianissimo User

    Jan 8, 2015
    North Yorkshire
    I read on the Warburton website that in their experience of setting gaps for customers, between an eight of an inch to one tenth of an inch seems to be a common optimal for most.

    Interesting point about the height. To do my rough measurements, I used a small, slim piece of plastic to push down into the mouthpiece receiver until it met the top of the leadpipe. I noticed with the Olds Special, I could barely detect the leadpipe as it is so thin. I guess the thickness of the leadpipe wall must be tapered almost to nothing, and therefore there must be quite a 'step' where the mouthpiece backbore ends, regardless of whether there is a gap.

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