Is definitely possible to get to 150's on single sub set ups and 4 inch ports. At the show this past weekend I did a 150.5 on a dd9515 with a zx1500.1. SPL setup of course, but its possible. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif