I currently have a ssd15 in about a 4cuft box with an 8" sonotube port... the port i believe is causing unloading problems because it is so long it is basicaly resting o. The motor of the sub. So would one 6" pvc port be big enough? Ill flare the ends either making fiberglass flares or heating the pvc up annd forming it around a dog water bowl. But please... im getting slightly aggrivated...

One 6" is too small in my opinion.

Alright well i think im going to try and make a fiberglass right angle for my sono tube then to hopefully fix the unloading issue...

I've been fooling around with the idea of a round port to save space on my first box build, but after plugging in numbers and doing the reasearch on some of the websites posted by some of the guys here, I now understand why most people say "Just build a slot port and be done with it." I haven't ruled it out completely because firing an 8" port through the rear deck sounds awesome, it might be out of my league though.

Try 2 4" aeroports. It was enough with my Xcon 15", or with a 15" BTL N2. Enough for my taste. No port noise, no problem at all.

I think im going to cut up my box a little abd make a 18 1/8th" x 3" slot port. And hopefully be able to tune the box quite a bit lower! Lol its tuned around 35 or so and its too high for my taste... i believe my box has a rather flat response but i dont feel it is nearly as loud as i was hoping it to be. So im going with a bigger port tuned lower.