no front loading? (BD-Design)

I follow a different path. with my Oris 150 horns and Fostex t900a bullet tweeters I use a Bill Fitzmaurice designed subwoofer/woofer which is his HT Tuba sub. The 18 cu. Ft. (507.9 liter) bass enclosures are a front loaded folded corner horns with 11.4 ft. (3.47 meters) of horn length folded inside the box. A 15" anodized aluminum cone, 130 oz. magnet woofer, the Dayton RSS390HF-4 15" Reference HF Subwoofer 4 Ohm drives the corner horns. The corner horns sit in a 18mm teak veneered sand boxes containing 100 lb. (45.45 kG) of fine white sand. Another 50 lb. (22.68 kG) of sand is contained in the burgundy bags atop the woofer horns. The truncated pyramid Oris/Fostex horn stands contain 100 lb. (45.45 kG) of sand and a proprietary resonance damping mechanism. The 1 and 1/4 " (3.18 cm) thick granite slabs under horn stands are laminated to 1/8" thick neoprene rubber sheets. The room's walls have been reinforced to make them more corner horn friendly.

I use the DEQX HDP-3 preamp/digital sound processor for crossover, room correction, phase correction and time correction to the point where the signals from the corner horns and Oris/Fostex horns as though the distance to the acoustic centers of all three drivers were within 3 mm, less than 1/8" of each other.

In room frequency response at my sitting position is 19Hz to 20 kHz plus or minus less than 4dB. The sound is wonderfully transparent, dynamic, lightining fast and seamless. Imaging is remarkably good though not equal to good flat panel full range electrostatics.