Bruno Tilz 215-3 C vs Bruno Tilz 306-5 GS
the Bruno Tilz 215-3 C has a larger throat opening.
Mouthpiece A
Bruno Tilz 215-3 C
• Trombone
CatalogCup diameter26.00 mm / 1.0236 in
Cup depthMedium
Rim width—
Throat diameter7.00 mm / 0.2756 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Bruno Tilz 306-5 GS
• Trombone
CatalogCup diameter26.00 mm / 1.0236 in
Cup depthMedium
Rim width—
Throat diameter6.80 mm / 0.2677 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
Cup Diameter
Both mouthpieces have virtually identical cup diameters at 26.00 mm / 1.0236 in.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bruno Tilz 215-3 C has a wider throat (7.00 mm / 0.2756 in vs 6.80 mm / 0.2677 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Both mouthpieces are categorized as "Catalog" — the physical dimensions above will determine which suits your embouchure and playing style better.