Editing Audio crossover (section)

=== Models and simulation ===
Professionals and hobbyists have access to a range of computer tools that were not available before. These computer-based measurement and simulation tools allow for the modeling and virtual design of various parts of a speaker system which greatly accelerate the design process and improve the quality of a speaker. These tools range from commercial to free offerings. Their scope also varies. Some may focus on woofer/cabinet design and issues related to cabinet volume and ports (if any), while others may focus on the crossover and frequency response. Some tools, for instance, only simulate the baffle step response. 

In the period before computer modeling made it affordable and quick to simulate the combined effects of drivers, crossovers and cabinets, a number of issues could go unnoticed by the speaker designer. For instance, simplistic three-way crossovers were designed as a pair of two-way crossovers: the tweeter/mid-range and the other the mid-range/woofer sections. This could create excess gain and a 'haystack' response in the mid-range output, together with a lower than anticipated input impedance. Other issues such as improper phase matching or incomplete modeling of the driver impedance curves could also go unnoticed. These problems were not impossible to solve but required more iterations, time and effort than they do today.