Editing Audio crossover (section)

====First order====
First-order filters have a 20 dB/[[Decade (log scale)|decade]] (or 6 dB/[[octave]]) slope. All first-order filters have a Butterworth filter characteristic. First-order filters are considered by many [[audiophile]]s to be ideal for crossovers. This is because this filter type is 'transient perfect', meaning that the sum of the low-pass and high-pass outputs passes both amplitude and phase unchanged across the range of interest.<ref name="Ashley1962" /> It also uses the fewest parts and has the lowest insertion loss (if passive). A first-order crossover allows more signal content consisting of unwanted frequencies to get through in the LPF and HPF sections than do higher-order configurations. While woofers can easily handle this (aside from generating distortion at frequencies above those that they can properly reproduce), smaller high-frequency drivers (especially tweeters) are more likely to be damaged, since they are not capable of handling large power inputs at frequencies below their rated crossover point. 

In practice, speaker systems with true first-order acoustic slopes are difficult to design because they require large overlapping driver bandwidth, and the shallow slopes mean that non-coincident drivers interfere over a wide frequency range and cause large response shifts off-axis.