Yamaha YHR-667D Geyer Series Detachable Bell Double French Horn
Yamaha Quality and Design

Geyer style wrap
A horn with a Geyer style wrap has the 4th valve on the far end of the other valves with a long thumb lever. It is an open wrap with very few sharp bends in the tubing.

Hand-lapped rotary valves and slides
Rotary valves and slides that have been hand-lapped are airtight and have smooth action.

Articulated key levers
Articulated key levers have responsive motion.

Hammered and annealed bell
Hammering and annealing are processes so important to the instrument's acoustic characteristics that Yamaha employs computer-controlled equipment to ensure consistently superior sound. Hammering enables bells to have a rich, resonant tone that blends beautifully with other instruments. Annealing is a cooling and heating process that makes it easier to control the acoustics of the instrument.

Cyclical bore
A cyclical bore is a perfectly cylindrical tubing assembly in combination with a conical mouthpipe and bell system. This allows for consistent air flow throughout the horn.

Tapered valves
Tapered valves wear for a long time without air leakage.

Excellent sound in all registers
The combination of the secure high register, strong projection, and quick attack of the Bb horn with the rich, warm timbre of the F horn make the double horn ideal for most playing situations.