Originally Posted by kevinzoe
I think the Sonotube is a great way to get started for your polys. I ordered a 12foot long, 48"diameter sonotube that had to be delivered on a flatbed truck!!!
Yeah, current plan is to pick up several, none quite that big, and get them home on my GF's dad's full size pickup, with probably about 3 feet hanging off the back red flagged.
I never thought of veneering sonotubes but that's a great idea. I was just going to paint mine (I don't have any obvious wood in my theatre anyway). That totally explains the shape of yours since when I first looked at it it didn't look like the buckled-panel style you normally see with wood - too much continuous curvature. I've seen some others make part-round ones by bending lauan over shaped ribs but hadn't seen your approach before.
Yeah, slightly closer seating distance is one reason I think they'll work well in my room, as my theatre is a converted upstairs bedroom so not really a cavernous space.
I'd be a little concerned about flex in the middle of the well bottom. I guess that would be alleviated with glue/caulk. Of course it depends on the dimensions. I think 2' x 2' would be good, but maybe 4'x4'. The 4' span would likely need some reinforcement midspan.
I think because the other direction is so short and the dividers should be plenty rigid in/out, if you continuous glue to the dividers (and caulk only improves it) you should be fine. If not then reinforcement would be a good idea - also making the well bottom out of thicker material (thicker than the dividers) to provide a little more stiffness between reinforcements.
I'm certainly interested in knowing how to implement though. Besides the source you referenced, where do you suggest studying?
The tough part with our rooms is that they are all quite different. Everyone sits at different distances and has different speakers with different directivity. We will likely have one or maybe two diffusers available. This makes for a one-size-fits-all situation.
You have as wide a diffuser as you may want if you make an inverse panel available as well. Then you can modulate with Barker code and place as many side by side as you like while still maintaining good operation. The page for QRdude tells you how to do that. One of the ideas of the styro one is that the company might cut it to a custom length so you aren't stuck with a Xx2' or Xx4' situation - also since you'd get an inverse panel with every main panel you'd be all set to implement the Barker code without having to now offer 4 diffusor kits. Although with that one you could probably just make one 2'x2' styro set, and one could make a 4' diffusor by just stacking the two styro pieces and using longer dividers. Not that you couldn't probably do just as well by stacking 2' all-wood units - from that standpoint you might just be able to make a main and an inverse in 2' long and call it done. Lots of different ways to go about it.
As for studying acoustics, it's not an easy question. I'm still quite early in my study. My general observation is that there's sort of a gulf between the theoretical and the practical, in that there are books that teach you the technical parts of acoustics and books about "how to build a recording studio" or whatnot, but no books about why and how to apply the former to the latter. The hardest part seems to me to be figuring out when to apply what type of device and why - and it's filling in that gap that seems (to me) to be the real trick. I could be totally wrong though, since I haven't read many books on the subject yet. Maybe some of the studio design books actually help bridge the gap. My journey through the subject feels very, well, roundabout so I'm not sure I can tell you an "efficient" way to learn (a bit about) acoustics. That said, here are some places listing good acoustics information:
I've learned an awful lot by reading studiotips and gearslutz, but it's not very efficient. However since those guys are mostly discussing implementations of theory rather than theory itself, it is one thing that somewhat helps bridge the gap as it were.
Some standards for multichannel mixing rooms that can be downloaded for free (and I don't think are listed above) are AES-TD1001, ITU-R BS775-1, NARAS P&E wing recommendations for surround sound production, EBU 3276. Also there's a document called "The EBU's multichannel audio activities" that has a nice bibliography of their stuff at the bottom.
I think it's key to learning acoustics to get a measurement rig with REW, fuzzmeasure, ETF, whatever. I found information on what to get kind of spread all over the place. And as if that wasn't PITA enough, the information on how to apply it is sort of spread around too. But getting a measurement rig set up, making some measurements in various ways, then reading and figuring things out, making more measurements, yadda yadda yadda has turned into a repeating cycle that gets me deeper into the rabbit hole every time I do it. So I think that is key to really getting a handle on it.
Enjoy the journey!