As software evolved, Mathcad changed its licensing and versions (transitioning to Mathcad Prime). This created a hurdle for users with legacy worksheets. However, the community has remained active in keeping King’s methodologies alive. For modern builders, using these worksheets often requires: An older version of Mathcad or a compatible viewer.
The math said it would work.
She plugged it in. The drive whirred to life, a small miracle. Inside was a folder titled “Mathcad Worksheets.” martin j king mathcad worksheets
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This worksheet models classic transmission line enclosures. Users input the Thiele/Small parameters of a specific driver, define the length of the line, and set the cross-sectional areas at the start and end of the tunnel. The sheet outputs the predicted acoustic output from both the driver cone and the line terminus. 2. Mass-Loaded Transmission Line Sheet (ML TQWT / ML TL) As software evolved, Mathcad changed its licensing and
King extended his models to cover complex horn geometries. By treating a horn as a series of cascading quarter-wave sections, his sheets accurately predict the acoustic loading, efficiency gains, and impedance spikes of complex back-loaded horn enclosures. How the Worksheets Changed Speaker Building
Many designers transitioned toward open-source platforms like GNU Octave or Python to replicate King's matrix-based acoustic calculations. For modern builders, using these worksheets often requires:
PTC’s modern version features a built-in converter to translate older worksheet formats into Prime format.
While Martin J. King’s worksheets remain legendary, modern DIY builders face two major hurdles when trying to use them today: 1. Software Compatibility
[Input Driver Parameters] │ ▼ [Define Duct Geometry & Length] │ ▼ [Simulate Raw Frequency Response] │ ▼ [Add Virtual Stuffing/Damping] ──► (Smooths out sharp resonant peaks) │ ▼ [Optimize Driver & Port Location] ──► (Cancels unwanted harmonic ripples) │ ▼ [Finalize Enclosure Blueprint]
For the aspiring DIY loudspeaker builder, Martin J. King's Mathcad worksheets represent the difference between building a piece of furniture and building a scientific instrument for music reproduction. They are an unparalleled resource for predicting, analyzing, and optimizing transmission line designs before you ever make a single saw cut.