Once you go below 100Hz there are rapidly diminishing returns as far as arrays go. Yes, they can achieve higher sensitivity and lower distortion than typical direct radiators, but in terms of size don't do so in a smaller package than a basshorn, and in terms of cost don't come close to a basshorn's economy. I use arrays in my HT for the left.center and right channels, and a folded horn for the sub, utilizing each technology where for my needs they do the best job.