Brochure

The Backbore
The backbore of a mouthpiece bears a
certain relationship to the rim, cup shape
and throat, and to the make and bore of
the instrument on which the mouthpiece
is to be used.
If the backbore of a mouthpiece is too
small, the high register will be stuffy and
flat. If the backbore of a mouthpiece is
too large, the mouthpiece will not have
sufficient resistance and the player’s
embouchure will soon become exhausted.
The use of the general terms “large”
or “small” to describe backbores must be
viewed from the standpoint of playing
qualities. It is not actually possible to
identify backbores by size alone because
they also vary in shape and rate of taper.
Various combinations of size, shape, and
rate of taper make the tone darker or
more brilliant, raise or lower the pitch
in one or more registers, increase or
decrease volume.
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Standard Backbores
Standard Vincent Bach mouthpieces
match the playing qualities of the
backbore with the design of the other
components. The following chart lists
standard backbores.
TRUMPET AND CORNET
Models without letters-No. 10 backbore
“A” Cup Models-No. 24 backbore
“B” Cup Models-No. 7 backbore
“C” Cup Models-No. 10 backbore
“D” Cup Models-No. 76 backbore
“E” Cup Models-No. 117 backbore
“F” Cup Models- No. 76 backbore
“V” Cup Models-No. 25 backbore
FLUEGELHORN
No. 112
HORN
No. 602
TENOR TROMBONE (SMALL SHANK)
No. 402 most models
No. 413 6 1⁄2AM
No. 420 6 1⁄2AL • 5GS
BASS TROMBONE • LARGE SHANK TENOR
No. 429 most models
No. 800S 1G • 11⁄4GM • 11⁄2GM
No. 413 6 1⁄2AM
No. 420 6 1⁄2AL • 5GS
TUBA
No. 801 most models
No. 810 24W • 24AW • 7 • 18
NOTE: Numbers are factory part numbers
for tools. There is no numerical relationship
to the size and shape of the backbore.
Special Backbores
Players may request special backbores
when they are comfortable with the cup
and rim design, but desire a slightly dif-
ferent tone quality. Special backbores are
available on any Bach mouthpiece. The
following is a list of available backbores
and the general playing qualities of each:
TRUMPET
No. 24 bigger, darker, symphonic
No. 7 dark, Schmitt-style
No. 3 dark
No. 117 favors the upper register,
standard piccolo trumpet
backbore
No. 87 big, free blowing
No. 76 bright edgy sound; helps
upper register
No. 41 bright, more resistant
No. 57 lively, helps raise pitch
on some notes, good
high register
No. 25 big, free blowing, good
commercial sound
FLUEGELHORN
No. 119 more resistant, brighter
HORN
No. 614 free highs
No. 613 big, open
TENOR TROMBONE (SMALL SHANK)
No. 413 symphonic
No. 420 dark, euphonium
No. 411 warm, lyric tone
BASS TROMBONE • LARGE SHANK TENOR
No. 428 slightly larger, darker
No. 800S larger, darker, more free
blowing
No. 420 dark, euphonium/tenor
backbore
No. 413 symphonic tenor backbore