Designing High-Performance Loudspeakers with Martin J. King Mathcad Worksheets

Initially, Martin King offered his Mathcad worksheets for non-commercial use. However, due to high demand and administrative overhead, he eventually transitioned to a paid licensing model .

Back-loaded horns are highly popular among single-driver, full-range speaker enthusiasts. King’s BLH worksheet models the horn profile (exponential, hyperbolic, or conical) and simulates how the rear radiation of the driver couples with the room. It accurately predicts the mid-bass dip common in poorly designed horns, allowing the designer to fix it in software first. 3. The Open Baffle (OB) Worksheets

Mathcad was chosen because it combines live mathematical notation, text, and graphics in a single sheet. Unlike "black box" simulation software, King’s Mathcad sheets allowed users to see the exact formulas calculating the acoustic behavior. Key Benefits of the Worksheets

She plugged it in. The drive whirred to life, a small miracle. Inside was a folder titled “Mathcad Worksheets.”

The worksheets show how different designs affect the "baffle step" response or how to mitigate undesired cabinet resonances. How to Use Martin J. King Worksheets

Moving the woofer down the length of the line alters internal standing waves.

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

However, the legacy of his equations remains foundational. The engineering models he popularized have since been integrated into, or adapted by, other loudspeaker simulation software packages:

When you open a standard MJK worksheet (e.g., TL Open End V4 ), you will see a vertical stream of calculations. Do not try to read it like a book from top to bottom immediately. Look for these structural elements: