An automated Windows 95- program has been developed to optimize the placement of listener, loudspeakers, and acoustical surface treatment, as well as the room dimensions in critical listening rooms. The quality of the low-frequency room response is monitored in terms of the spectra received by the listener over just the early reflections (65 ms) and also over multiple (15-30) reflection orders. This amounts to monitoring the effects of comb filter coloration due to early arriving reflections and the quality of the modal response, respectively. The program uses optimization routines to achieve the flattest response over these two spectra, while satisfying displacement, symmetry, and stereo angular constraints. This has required the development of a cost parameter to monitor the quality of the spectra produced. The cost parameter is equal to the combined, weighted standard deviation of the two spectra. To provide good imaging as well as bass response and account for physical limitations on listener and loudspeaker placement, limits can be placed on listener and loudspeaker search ranges. The first order specular reflection points are determined for the optimum listener and loudspeaker locations to aid in the placement of absorbing and diffusing acoustical surface treatment. The room dimensions can also be included in the optimization, although this feature is not included in the initial version. Wizards are provided for stereo, stereo with multiple woofers per loudspeaker, stereo plus center channel, 5.2 THX home theater surround and multichannel music (using five matching loudspeakers), and sub-woofers. Additional configurations can be created, saved and reloaded for evaluation. The program's output can be printed and also saved in a comma delimited form for more detailed evaluation in a spreadsheet. The wizards help the user by automatically setting up the constraint relationships among the independently varying drivers and the constrained dependent drivers, in addition to setting limits on the search ranges for the listener and loudspeakers. Examples of some of these wizard configurations are also presented.
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