You could build 10Pi style boxes for Theater4/7 parts. Then lf response would be 25-30hz, and sound a bit warmer. The cabinets however, would be huge! But I'm willing to bet that you will find the bass of 10Pi horns to be prodigous. There is very little musical information below 40hz. Unless you're into music featuring pipe organs or dueling bassoons, the 10 Pi is the way to go. Take care, Steve