OK(if I may step in here).... But what is the hearing difference and what is it that you are correcting for that you can hear a change for? Since I have a line of 16 3.5 inch woofers connected to a line of 3/4 inch dome tweeters with flanges cut to a c-to-c of about .9 inch, what difference would I hear by adding anther line of 3.5 inchers on the other side of the tweeters? I'd also have to be careful of the distance between the woofers causing potential horizontal comb filter issues.