I am fully aware that this is a broadcast forum and most of the comments I see are directed to video or high end video equipment and technology, so I am going to humbly and respectfully request great leniency and tolerance to this forum since this question is of audio nature. It's just that I am hopeful that someone among you might have the answer for it since I can feel the Guru ripple out there. I know there seems to be a consensus of opinion especially among us rappers, hiphoppers, and regaetoners, that the bigger the subwoofer and the louder the low end, the better and more exciting the sound. But I want to appeal to the technically correct rather than to the excitement of my guts being blended. Here's the question: If I have two JBL Control 29 AV-1 speakers(one 8" woofer and one horn equipped 1" titanium driver each)and I want to array them horizontally or vertically (doesn't matter) and add a sub. What size speaker should I use for the sub and still keep my SPL and post speaker dynamics healthy? a 12" a 15" or an 18"?