I'm about to make sonotube sub project, and I'm just hoping to borrow some peoples ears to get some advice on the final tuning of it. All this sub stuff has just made me realize that I've been out of stereo-land for too long as far as the technical side goes and I seem to have pretty much forgotten everything. I came about the sonotube idea based from the reccomendation from a bud on another forum (I would almost assume he's a member on here somewhere). I trust his ideas, but right now I'm starting to feel guilty for asking him soo many questions, so I'm hoping to ease his burden here. Quick Background- Getting married soon, moving into a condo... my options lean towards small enclosures. I currently run Marantz sr5200 reciever, energy C3 shelf speakers switched that I recently switched to, (energys have excellent sound quality IMHO, but I'm used to having two 6.5" on each main speaker so I find that i'm missing that. I'm starting to lean towards wanting a little bit of extra bass for music now) The parts- The amp is the non bass boost 250watt version from PartsExpress. The proposed enclosure is sonotube. For the sub... between PPI flat piston 12" I have and JLaudio 10w3v2 (2 ohm coils), the 10" JL looks like it will be my choice. According to real-world from when they were in my car, and according to WinISD. Short-cut to JLs specs on this woofer so you can follow along as well here... *edit- guess I can't post URLs yet. add www and cut and past this jlaudio.com/subwoofers/pdfs/10W3v2_MAN.pdf * ------------ bla bla bla close to time for those exciting Qs (I say that loosely) basically with future-wife-imposed size constraints, and what WinISD says, the JL looks like a good compromise for my situation. It still has excellent peak excursion and I already know I like the sound of the sub. From there... I've now decided on 14" sonotube and I'm going to play around with a 60L ported enclosure (port length was around 24" I think... my papers in the garage now... *sigh*), and I also want to try something around 30L with a sealed enclosure. I really do prefer tighter bass so the sealed enclosure will be a bit of an experiment. If you put in the specs of the JL into WinISD it comes out with enclosures close to these sizes anyway. The horrible reality of me playing with WinISD is that I truly believe I have forgotten everything. The phase plot part of WinISD seems useless in this scenario. I don't see how the phases will be a problem for me. The group delay on the sealed box peaks at 6ms, and 29-30ms for the ported enclosure. To me, this seems really high...Is there any way to bring the delay down on the ported enclosure, or should I even bother? Maybe this will boil down to personal preference, which is why I think I should try both. What about for the ports, where's good to read about port considerations? Am I fine at the legnth of port it's at? How important is that bell shape on the end of the ports... I can duplicate something with router bit, but does it really need the special acoustic bell mouth like I see on a lot of the DIY sonosubs. I come accross soo many little rules of don't go beyond this volume and don't beyond go this length... I do believe I'm past the length already... how much of a consideration should this be? and what about port velocity... does the mach .09 this configuration comes out to, equate to noticeable in real-world? Thanks for any suggestions, you can probably see why I felt guilty for bugging my bud about Qs.