Convention Paper
Parametric Control of Filter Slope Versus Time Delay for Linear Phase Crossovers
AES Convention 119 · Paper 6565 · October 2005
Abstract
Linear phase crossover filters are a powerful tool for sound system designers. They deliver a near-ideal response with ruler-flat pass band, steep transition slopes and adjustable stop-band rejection – all with zero phase shift. Transition slopes can be matched to a target response, for example 24 dB or 48 dB per octave, and can also be arbitrarily specified while still retaining a perfect-reconstruction characteristic. Practical application of linear phase crossovers requires manipulation of center frequency, transition slope and stopband rejection. A graphical user interface is described which gives users new degrees of freedom in defining linear phase filter parameters. By setting bounds for parameters such as delay, a user can continuously vary other parameters while the graphical user interface optimizes the resulting filter. This paper presents new parameters for optimization of a target transition slope within a bounded delay parameter, providing fast and efficient user controls for working with and adjusting the crossover filters in real time.
