just finished building the first prototype of this project. it is 70cm deep 57cm*57cm mouth. driver faces back of the cab where there is an access hatch with a phase plug attached. horn path goes round 90 degree bend and then straight to the front. chamber for driver is in the middle of the box with vents entering horn path about 15cm from the mouth.
it was designed to cover 70Hz to 320Hz. sounds pretty good compared to double 15" vented cab. got similar output with ultradrive set 2-3db lower for the horn. as the horn was 8ohm and the vented box 4ohm this makes it 5-6dB more sensitive as predicted by hornresp. sounded a bit faster and more defined - was able to pick out some detail on basslines that was just a constant drone on the vented cab. tried some vocal stuff through it and it sounded no worse than the vented cab. cone excursion was at least half for the same output.
as I have recently lost my microphone, laptop and camera phone to thieving ***** can't give any accurate info at this stage - perhaps if anyone in Bristol is interested they might come and measure it and help me tune the ports for a few beers???
