Design Goals

To create a loudspeaker which can reproduce 110db@1M without massive compression. In order to ease the difficulty, the speaker need only reproduce 80 hz and above. It must also be able to be used in a complete six-channel home-theater configuration. Efficiency must be at least 90 db (@1W/1M). I also sought to apply the lessons learned from my previous speaker design the argonaut prestige.

Driver Selection

For the tweeter, I chose to use the Morel MDT-30. This is the cheapest "high-end" tweeter I know of, performing just below the Dynaudio D-260 and Scan-speak 2905/9XXX series. If offers low-compression, the impetus for this design and a smooth response. In addition it's ferrofluid dampening removed the need for a series notch filter.
The woofer was a difficult choice, for the power handling aspect, I had narrowed it down to five choices. In the end I threw away the unwritten rule which says 8" and larger drivers should not handle midrange and selected a 8" mineral-filled polypropylene cone woofer. The P21WO-20-08 to be exact. It offers smooth response and good power-handling with a 40mm voice-coil. Compression? I really can't say for sure, but with the large surface area of the cone, and the stiff sealed enclosure, I would guess that compression will be low.

Enclosure Alignment

I chose a 2nd order sealed system of 22 liters for the enclosure. This creates an F3 point of approx. 60 hz. In small rooms the bass may actually sound satisfying. However my listening room is 14' by 24' and needs a subwoofer to fill out the low end. The crossover circuit includes a bypassable 1st order filter at 90 hz.