I am playing with the numbers to build a 250-300l tempest. Tuned to 19.5 hz. My question is, how low do I need to go? About the best I can come up with is 110db at 20 hz. Is 20 hz too low? This is for both music and HT. I am assuming that lower is better and with a nice flat plot line. What about 33 ms delay? Is that a problem? Thanks to you all!