Hans Hoyer 6801A French horn (detachable bell)

• Lacquer finish
• Bore size: 0.468 in. (11.90 mm)
• Bell diameter: 12.204 in. (310 mm)
• Gold brass leadpipe
• Kruspe wrap
• Mechanical lever action
• Detachable bell
• Adjustable thumb lever
• Lightweight case

Most modern full-double French horns follow either the Kruspe or Geyer layout. They differ principally in the position of the F/B-flat change valve, which is operated by the thumb to switch the instrument between the F and B-flat sides. On a Kruspe-wrap horn, the change valve is positioned close to the first valve. On a Geyer-wrap horn, it is located after the third valve, creating a more open arrangement of the tubing.

Many players associate Kruspe-wrap horns with a broad, rich orchestral sound and Geyer-wrap horns with a more direct, free-blowing response, although bell design, materials and leadpipe also influence an instrument’s playing characteristics.

No. Kruspe- and Geyer-wrap horns use the same fingering system and are played in exactly the same way. The difference lies in the layout of the tubing and the playing characteristics of the instrument rather than its operation.

A fixed-bell horn has the bell permanently attached to the instrument, while a detachable-bell horn allows the bell flare to be removed for transport or storage. This allows the instrument to be packed into a smaller case, making it popular with players who travel frequently or prefer a more compact case.

When assembled, a detachable-bell horn is designed to offer playing characteristics comparable to those of an equivalent fixed-bell model, so the choice between the two is usually based on portability rather than performance.