Does sonotube need to be flat...

[riceaterslc]

on the inside? there is a severe lack of sonotube here, but there is plenty of plastic water pipe in a variety of diameters. however, the inside of the pipe has small grooves, maybe 1/4" at the most deep and 1/8" max width. would this be suitable to use in substitute of sonotube? thanks!

[Fred333]

Interesting question. I think it does have to be flat just from the sounds wave perspective. I would try and see what sounds better.

[chasw98]

Chris:
Will it matter if you coat the inside with acoustic foam? I don't think it will. If the pipe doesn't cost to much, go ahead and experiment!

Chuck

[BobEllis]

You may want to run a few ribs top to bottom to keep it standing straight. A thin layer of canned foam (Great Stuff or similar) would do the same thing and make the walls deader.

[riceaterslc]

Chris:
Will it matter if you coat the inside with acoustic foam? I don't think it will. If the pipe doesn't cost to much, go ahead and experiment!

Chuck

ha, Cpt Obvious is not my friend, i didn't even think of the lining. hopefully i'll have a section by this weekend.

chuck, what kind of port did you end up going with? i read through your build thread but couldn't see if you decided on a single 4"...

[Kevin P]

I don't see the ribs being an issue for bass frequencies (bass wavelengths are far longer than anything those ribs will effect) but I'd be more concerned about the tube flexing or resonating. If it's as stiff and "dead" as sonotube I don't see why it wouldn't work.