As a long-time audio freak and music lover and sometimes DIY loudspeaker systems builder, I've long been intrigued by horns, up till now, mainly bass horns, But the seemingly rather simple construction of of the Smith Horn as shown in Ruedigger's posting of Smith's original article prompted me to consider building a pair--I'll probably get around to it next summer when I'm "off contract" at the University for a month. I've used the Eminence ASD1001S driver and like it for several reasons--even though it's inexpensie, it's well constructed and has a smooth, non-peaky, hi-fi-like response, devoid of the severe peaks and dips in the 7-12 kHz range that impart that shrieky, fatigue-inducing harshness that mars the performance of many drivers in its price range--and some that cost a lot more, too. And it works very well with the small elliptical waveguide sold by Parts Express. Admittedly, its response dwindles rapidly above 18 kHz, but my hearing dwindles rapidly above 13 kHz, so that's a non-issue. Anyhow, I think it'll be a good way to get a feel for this design and let me know if I want to scale the design up for a 2-inch driver--the taper, for an 800 Hz crossover, would be the same, only the vertical dimension wouold change. The reproduction quality of the article was poor, and the drawing looked rough and not exact anyhow. I've analyzed the geometry of the design, and made a few non-critical modifications in the views attached, courtesy of Adobe Photoshop, v. 7.0.