D.P.R.W.G. - Double Parabolic Reflective Wave Guide 

The high frequency section of the Butterfly system is equipped with a 3” (1.41” throat) compression driver coupled with a D.P.R.W.G. (Double Parabolic Reflective Wave Guide) device, another Outline invention for which an international patent has been applied for.

The result of three years of research and tests, the D.P.R.W.G. is a really original device and is geometrically based entirely on precise mathematic calculations.

It has the job of taking a circular planar (flat) wavefront emitted by the source at its input (e.g. that of a compression driver) and transforming it into a rectangular planar wavefront at its output, keeping signal paths identical from every emission point of the source.

The rectangular planar wavefront thus obtained can be loaded by an appropriate horn or waveguide to ensure the necessary coverage. (*)

SINGLE HI-PACK ELEMENT RESPONSE (with D.P.R.W.G.)
 

                    4m free field measurement referred to 1m

Original component positioning has resulted in extremely uniform on and off axis horizontal response over a very wide range of frequencies. Measurements at 45° (above) show how directivity is constant from approximately 700Hz up to the highest frequencies. Looking at the diagrams, it's impossible to see where the crossover frequency is (approximately 1250Hz), which goes to show that the components are perfectly in phase.

(*) Source: Butterfly System White Paper by Guido Noselli