I suggest avoiding all hybrid planers. Getting rid of the box is only half the advantage available to a planer design. The other half is the full range driver.
Crossovers, especially in the midrange, ruin the continuity of the sound. Full range electrostatics are the most successful designs, despite their power and size requirements. Quads, Acoustats, and Soundlab are the best known, but many choices are available including several DIY designs.
Crossovers, especially in the midrange, ruin the continuity of the sound. Full range electrostatics are the most successful designs, despite their power and size requirements. Quads, Acoustats, and Soundlab are the best known, but many choices are available including several DIY designs.