About 3 years ago I acquired 2 EV 15B speakers, got the plans from EV for the TL505 cabinet, and built them. Now I am using them for bass, and they really don't sound like they should with a Carvin R600. I feel that they fart and can't put out the low bass and volume I would expect them to do. Dimensions are 23 3/4" H x 19 1/4" W x 17" D... similar to the one at: http://www.intp.us/mebombard/tl505_15.htm Sooooo... the questions are: 1. Can I change the open slot port to something better with the existing speaker? 2. Using WinISD's tone generator, how can I experiment with the port? 3. Should I change the speaker AND the port? Opinions are welcome and appreciated! Thanx!!!