These are the three primary resonator designs depending on the number of cones and the design of the bridge: The simplest resonator design is the biscuit-bridge single-cone, which looks like an inverted speaker cone.
This shiny, gleaming instrument has an unmistakable sound, a charming history, and versatility to spare.
Dire Straits even featured a photograph of Mark Knopfler’s 1937 National Style 0 Resonator Brothers in Arms on their classic rock album cover.
But, the Dopyera brothers formed the Dobro Manufacturing Company and originally made the resonator.
The first resonators came with square-neck lap steels to feed the Hawaiian music craze of the mid-1920’s.
According to Wikipedia, “A resonator guitar or resophonic guitar is an acoustic guitar that produces sound by carrying string vibration through the bridge to one or more spun metal cones, or resonators, instead of to the soundboard, or guitar top.” That tidy definition doesn’t say how many types of resonator guitars are out there.