Guitar Dictionary Category
Slide, Resonator & Steel Guitar
What Is a Resonator Cone?
A resonator cone is a thin spun-metal diaphragm inside a resonator guitar. String vibration travels through the saddle and bridge assembly into the cone, which moves air and produces the instrument’s characteristic attack and projection.
The cone is normally made from aluminium alloy. It is much lighter and more flexible than the decorative coverplate above it.
Three Main Cone Systems
- Biscuit cone: one cone faces upward and supports a small round wooden biscuit bridge at its centre.
- Spider cone: one inverted cone supports a cast spider bridge around its outer area.
- Tricone: three smaller cones are connected by a T-shaped bridge assembly.
The bridge system is inseparable from the design. A biscuit cone cannot simply be substituted for a spider cone without rebuilding the instrument around another structure.
Cone vs Coverplate
The cone is the vibrating internal part. The coverplate is the perforated metal guard visible on the guitar’s face. It protects the cone and allows sound to escape.
How Setup Affects the Cone
The cone must sit evenly on its supporting ledge. The bridge, saddle, coverplate clearance and string load must work together. Poor seating, a distorted cone or loose hardware can create buzzes, rattles and reduced sustain.
On a spider-bridge instrument, the central tension screw holds the spider and cone together. It is not a general tone control and should not be tightened casually.
Cone Tone and Replacement
Different cone designs and manufacturing methods affect response, but replacing a cone does not guarantee an improvement. The instrument’s body, setup, bridge and playing style remain part of the sound.
A dented cone can sometimes continue working, but severe distortion or damage may require replacement by a technician familiar with resonator instruments.
Why the Resonator Cone Matters
The cone is the mechanical heart of a resonator guitar. It performs the acoustic work normally associated with a guitar’s wooden soundboard and determines how the bridge’s vibration becomes audible sound.
Kalymi Tip
When a resonator develops a new buzz, check for loose external hardware first, but do not keep tightening the spider screw or coverplate screws in search of a quick cure.
My resonator lesson notes that intonation and response depend partly on the bridge system. Persistent tuning or rattle problems are good reasons to use a qualified resonator repair technician.
Protect the cone from pressure when the coverplate is removed. It is a thin acoustic diaphragm, not a rigid metal speaker part.
Related Terms
Learn More
- Top 12 Tips for Resonator and Lap Steel Guitar
- Open G Resonator Poster and Companion eBook
- Open Tunings Guitar Learning Path
- National Reso-Phonic Guitars
- Beard Resonator Parts and Cones
- Kalymi Music Library
Reviewed by
Brent C. Robitaille,
music educator and founder of
Kalymi Music.