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Resurrected crossover, box design, and room acoustics software for Mac

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  • Resurrected crossover, box design, and room acoustics software for Mac

    Back in the 1980's and 1990's I wrote several audio-related Mac programs which over the years stopped working thanks to Apple's hardware and software changes. I'm dusting them off and making them free for any commercial or non-commercial use, since emulation technology has given them a new lease on life and there seems to be a lack of such software (particularly crossover design) available for Macs. They can be downloaded here.

    I recently found the BasiliskII emulator which is very easy to install on modern Macs (no hunting down ROMs etc). In particular, I've been using the install, which bundles BasiliskII. My audio programs run flawlessly (and much faster) under the emulation, though you may have to adjust the Monitors control panel within the emulator to 256 color mode for compatibility.

    LMP Professional is a crossover design and speaker simulation program with an effective but embarassingly dated user interface. You model your drivers by selecting the cutoff frequencies, slope, and Q that best approximate their response curves, define your crossover, and the program plots the summed frequency and phase response. There is basic support for modeling diffraction loss (response step) and interdriver time delay. You can define the crossover either by providing component values for standard topologies or by entering the transfer function coefficients manually. The download includes a user manual, but for more technical detail refer to the 3-part 1987 article for Speaker Builder Magazine, An Introduction to Frequency Response and LMP, available here. Did I mention the user interface sucks?

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    TopBox for Macintosh, is a collaboration with famed speaker designer Joe D'Appolito. It has held up very well since it's inception in the 1990's. It supports 8 different closed, vented, and bandpass alignments and produces magnitude, max SPL, max input, and impedance plots. Joe's formulas enable TopBox to automatically compute optimal box volume and tuning for a given driver.

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    The Listening Room is a program for finding listener and loudspeaker positions that minimize the detrimental effects of standing waves and early reflection phenomena. The user moves the listener and loudspeaker positions in 3 dimensions and the program plots axial standing waves and early reflections. The program has an Optimize function that automatically minimizes standing wave activity. Full user manual included. Here are reviews from the time of TLR's release, referring to Sitting Duck Software founder Bill Fitzpatrick's port of the program to MS-DOS. Stereophile, Audio, Stereo Review.

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