Editing Audio crossover (section)

====Third order====
Third-order filters have a 60 dB/decade (or 18 dB/octave) slope. These crossovers usually have Butterworth filter characteristics; [[phase response]] is very good, the level sum being flat and in phase [[Quadrature phase|quadrature]], similar to a first-order crossover. The polar response is asymmetric. In the original [[Joseph D'Appolito|D'Appolito]] [[Midwoofer-tweeter-midwoofer|MTM arrangement]], a symmetrical arrangement of drivers is used to create a symmetrical off-axis response when using third-order crossovers. Third-order acoustic crossovers are often built from first- or second-order filter circuits.