What contributes to the dipole polar response of ORION+?
A perfect dipole generates sound pressure that varies as p = cos(angle) for different directions. Thus at 0 degrees p = 1 or 0 dB. At +/-45 degrees off axis the pressure is 3 dB down, at 60 degrees it has decreased to -6 dB, and at 90 degrees there is no radiation. The shape of the polar response is like two tennis balls that touch each other. A practical dipole like the Orion+ follows this pattern quite closely in the horizontal plane, but deviates from it in the vertical plane due to driver spacing and layout. Thus, horizontally, from the lowest bass frequencies up to about 400 Hz you have perfect dipole behavior. The open baffle is small compared to the radiated wavelength over this frequency range. Front and rear radiation interact freely causing the characteristic 6 dB/octve highpass response which is corrected in the ORION crossover/equalizer. Above 400 Hz the baffle is no longer acoustically small and the 8″ midrange driver begins to beam. Also the driver’s frequency response to
A perfect dipole generates sound pressure that varies as p = cos(angle) for different directions. Thus at 0 degrees p = 1 or 0 dB. At +/-45 degrees off axis the pressure is 3 dB down, at 60 degrees it has decreased to -6 dB, and at 90 degrees there is no radiation. The shape of the polar response is like two tennis balls that touch each other. A practical dipole like the Orion+ follows this pattern quite closely in the horizontal plane, but deviates from it in the vertical plane due to driver spacing and layout. Thus, horizontally, from the lowest bass frequencies up to about 400 Hz you have perfect dipole behavior. The open baffle is small compared to the radiated wavelength over this frequency range. Front and rear radiation interact freely causing the characteristic 6 dB/octve highpass response which is corrected in the ORION crossover/equalizer. Above 400 Hz the baffle is no longer acoustically small and the 8″ midrange driver begins to beam. Also the driver’s frequency response to
