[ H(z) = \fracz^-N - a_1 z^-(N-1) - \dots - a_N1 + a_1 z^-1 + \dots + a_N z^-N ]
An all-pass filter’s transfer function ( H(z) ) (in the discrete-time domain) has the general form: allpassphase
But there is a ghost in the machine. It’s a filter that doesn’t change the volume of anything. It leaves the frequency response perfectly flat. Yet, it is responsible for everything from the "sweetness" of a phaser to the tightness of a transient. [ H(z) = \fracz^-N - a_1 z^-(N-1) -
