This project combined the Focal 8V 4412 mid-bass driver with the Focal TC 90 Tdx tweeter in a straight transmission line. The cross-over used was a second order Bessel filter centered at 2500 Hz. Complete documentation of this project can be found in the following articles.

Derivation and Correlation of a Viscous Damping Model Used in the Design of a Transmission Line Loudspeaker System. By Martin J. King, 3/04/00

Upgraded MathCad Computer Models for the Design of Transmission Line Loudspeakers. By Martin J. King, 7/06/00

Recent Design Improvements for the Focal Transmission Line Speakers and the Fostex ML TQWT Speakers. By Martin J. King, 7/29/01