I'm planning on a 80 to 100L ported sonotube sub tuned to 19-20 hz using a Stryke AV-12 driver. I was using WinISD to help me figure volume, port length and tuning. I keep hearing a few people warn about the excursion limits of the driver in certain alignments. So I down loaded LSPCADlite and input the parameters I settled on from WinISD. Low and behold LSPCAD calculates a peak in excursion of 40mm at around 25 hz when the box is 85L @20 hz. To lower the excursion peak the box must be significantly smaller which causes the low freq. extension to suffer! The AV-12 has an Xmax of 23mm (one way) which I believe means that it is capable of up to 46mm of excursion. Is this true and is 6mm of headroom enough? Is the driver going to be distorting a lot that close to the Xmax?