Hi all. I'm looking to build a single large ported sub to replace the pair of very small sealed ones I'm currently using. Main use is for movies with the occasional bit of music, and the loudest i listen at is -10dB (semi-detached ). I am reusing the JBL drivers (GT5-12 14.2Xmax circ,24mmXmech)and have a maximum usable size of 240x75x28cm, I estimate the volume to be about 300L after bracing etc. Is building to such a shallow depth compared to the length a cause for concern? I've had a play with WinISD and think I'm pretty happy. I've modeled three different port tunes 19,17 and 15Hz. All three variations will hit 110dB with 150W and [email protected] from 50Hz upwards. Port velocity is below 17m/s and 30m/s respectively. I'm not sure which tune to go for and would appreciate any input. The 19Hz tune is -3dB at 17Hz. The 15Hz tune obviously digs the deepest (-6 @14dB) but is -5dB @20hz. How much should room gain affect my decision making? Thanks, Colin.