Most deviations between the simulation and a finished speaker can be traced to practical differences, primarily:
Are you planning a specific build and need advice on geometry?
Martin J. King transformed transmission line design from a dark art into a predictable, highly satisfying science. For anyone looking to understand the core physics of quarter-wave design, studying his original papers and worksheet methodologies remains an essential rite of passage. To help tailor this information further, let me know:
Before King’s worksheets, building a transmission line speaker involved guesswork, intuition, and "golden ratio" formulas. These older methods often resulted in boomy bass or severe mid-bass cancellation. King’s worksheets introduced several paradigm shifts: martin j king mathcad worksheets
Martin J. King's Mathcad worksheets are a specialized suite of simulation tools widely used in the DIY audio community for designing high-performance loudspeaker enclosures, specifically those based on . Overview of Worksheets
I can provide the specific geometric formulas and driver placement rules derived from King's original research to help guide your design. Share public link
: The worksheets were originally designed for Mathcad 8 , which had a free "Explorer" version for viewing and calculating, though it did not allow saving. Most deviations between the simulation and a finished
Because older versions of Mathcad (like Mathcad 11 or 15) can be difficult to run on modern Windows operating systems, many enthusiasts have translated King’s open equations into modern freeware like Hornresp or Leonard Audio's Transmission Line software . Conclusion
The Martin J. King Mathcad worksheets brought professional-level simulation capabilities to the hobbyist market. They are essential tools for anyone looking to go beyond basic box design and dive deep into the science of quarter-wave and open-baffle loudspeaker systems. By using these tools, designers can confidently simulate, refine, and build high-performance systems.
As of recent years, Mathcad has evolved (from Mathsoft to PTC), and the community has shifted toward open-source platforms like or R . However, King’s original .xmcd and .mcdx files remain perfectly usable. For anyone looking to understand the core physics
This is the crucial first step. Find a known "good" or "accepted" baseline dimension for the type of line you wish to build. Excellent resources for baseline dimensions are Bob Brines' website and Martin J. King's own "TL Alignment Tables," which provide great starting estimates.
What are you planning to build (e.g., transmission line, open baffle, or tapped horn)? Do you already have a specific driver model selected? Which simulation software do you currently have access to?