Owens Corning 703 vs. Roxul Safe 'n' Sound?

Happy New year Spencer. I'm still getting use to this Northwest weather, quite different from that of the California desert I spent six years in before moving up here. Everything is frozen in the morning! It's dark and cool all day during the Fall and Winter, which I'm really enjoying after being in blinding light and heat for six years. No more skin cancers! I've spent a lot of time on California beaches, and have paid the price.

I bought a nice piece of 1/2" X 2' X 4' plywood and cut it in four equal pieces 6" wide, from which a 6" deep frame measuring 4' square can be assembled. I then got a bag of Roxul Safe 'n' Sound, which contains twelve 3" thick pieces almost 16" wide and 48" long. Three pieces fit inside the frame, and two layers completely fill the frame's 6" depth. Perfect! One bag is just enough to make two absorptive panels, one of which I will position on the wall right behind my listening chair. I'll place the frame on top of a pair 9" Tube Traps butted up against that wall, and the combination of the Traps and panel should mitigate both reflections off the wall and the bass mode (present in all rooms at wall/ceiling/floor boundaries) at the listening position. I haven't done it yet, but Spring isn't that far away ;-) . 

Exactly so Spencer. I have a dedicated room and answer to no one but myself, but I have a fairly developed sense of aesthetics myself, and a desire for a nice looking environment in which to listen to music. I don't have to build any "real" bass traps (one of the disagreements between Ethan and Jon is in regard to what qualifies as one), as in the mid-90's I found thirteen of them, in sizes 9", 11", and 16", for ten bucks apiece (!) in The Recycler, a Southern California weekly "for sale" newspaper.

The music room in my new abode forces me for the first time to sit very close to the rear wall, hence the need for treatment of that wall. I have prioritized having my planar speakers 5' from the wall behind them over the listening position being away from it's wall, as the rear wave of planars really must be delayed at least 10ms behind the front wave, and distance from the wall behind them is the only way to achieve that. Ethan and Jon (and ya'll here on Audiogon) are giving me the info I need to do the rear wall "correctly". Thanks again!---Eric.

All good points, guys. My desire to get some absorption of lower frequencies at the listening position originates from having read that bass modes/nodes build up at not just room corners (though that is where they are most prominent), nor not just also along all the rooms wall/floor/ceiling intersections, but also along the wall itself---sealed rooms sound "bassiest" against their walls.

I know it takes a whole lotta material to absorb very low frequencies (below 100Hz), so perhaps going beyond the 2-3" of typical absorptive wall panels would bring marginal improvement in that regard. I have room to place a 9" ASC Tube Trap at either side of my chair, so I could do that and set the wall panels atop them. The rooms two front corners (behind the speakers) will have 11" Traps stacked on the big boys---the 16 inchers, the rooms back corners stacked 9" Traps.

Thanks again ya'll---Eric.

I didn't expect the extra space behind the panel to turn it into a bass trap! Just to lower its effective absorptive range a little. In the specs chart, it looks as if the Rockboard 60 may be a little better at higher frequencies than the 80, though the difference is marginal and perhaps insignificant. I don't want to over think this! But since the listening position has to be right up against a wall (to allow my dipole speakers to be positioned 5' from the wall behind them), and low-frequency eigenmodes run along room boundaries, absorption at as low a frequency as easily possible would be nice.

So I went to Home Depot last night, and though the HD website stated that the branch I went to had Safe 'n' Sound in stock (even the number of packages), I couldn't find any on the shelves. The HD "dude" couldn't even find it in the stores computer, telling me any acoustical product would have to be ordered. I went in to look at the stuff, to see if it is soft and loose like fiberglass insulation, or stiff like OC703. So Monday I'm going to Lowes, whose website indicates it has 2' x 4' Safe 'n' Sound in stock. We'll see!

Nah, I’ll make one frame sized to fit three pieces of the Roxul in, 45-3/4" x 48" interior. There is 56" between the two doors that flank the listening position, on the wall opposite the speakers. I might put a Roxul strip on each of those doors too, if they prove to be reflecting too much sound over to the lp. The space between the doors and the side walls is far enough away from the lp to be of no concern to me. That’s all the absorption I want---just to kill the first reflection from the speakers pointed at the lp wall.

The room sounds fine overall, no glaring problems as far as I can tell. I have ASC Tube Traps and a DSPeaker Anti-Mode for low-frequency eigenmodes, and MG CornerTunes and EchoTunes for any slap and flutter echo emanating from up near the ceiling. The wall behind the speakers will remain reflective---fine (in fact, preferred) for dipole speakers, as will the sidewalls---no need, due to dipole cancellation. First, I’m painting the room, this weekend, hopefully. I chose Sherwin Williams "Mink", a combination of gray and brown that is absolutely beautiful!

Thanks everyone. Home depot sells and stocks the Roxul 3" Safe 'n' Sound in a 12-pack of 15-1/4" x 48" panels for $46.27. Such a deal! Lowes sells them in the 24" width, but with a three package minimum. WAY more than I need.

Here's another question: Should I try absorption on the rest of the back wall (behind the listening position), not just directly behind my head?

Thanks again Brad, and howdy neighbor (sort of)! I’m pretty regular at Music Millennium, but hearing of Jack Pot and Artichoke is great news. I haven’t done much exploring in Portland yet, gotta get into it. I lived in Portland in ’77-8, and all the small records stores selling import LP’s and 45’s back then were gone when I got back up here last year, no surprise. But Music Millennium survives! My record store in L.A. was Amoeba, a pretty amazing place.

I’ve been to The Aladdin, saw Joan Osborne last Summer---great room, great show! Hey, if you have nothing better to do this Friday, I’m playing at JB’s Lounge at The Red Lion in Jantzen Beach, next Friday at Vinyl Tap in Milwaukee, and on the 21st at Laurelthirst on NE Glisan. Say howdy, I’ll buy ya a beer!---Eric.

Thanks auxinput. My ESL (old Quads) and magnetic-planar (Magneplanar Tympani T-IV) speakers don’t splatter much sound on the side walls, having the dipole null on either side and being pretty directional at higher frequencies, with the tweeter strips pointed directly towards the listening position at the mid-point of the opposite wall. They will be 5’ from the wall behind them, so diffusion should allow the rear wave to blossom well (one of the best things about planars imo), no need to absorb it. I’m not planning on getting actual real diffusers, having enough LP’s (about 3500), CD’s (around 6000), and books (if I can fit them in!) in racks to pretty much cover the room’s walls.

Thanks for the link Brad, but I don’t see it on my screen. Is it just me?! I need only to cover with absorption the 4’ x 4’ space behind my head on the wall which the listening chair has to be up against, unfortunately, to be able to get the planar speakers 5’ from the wall behind them, a higher priority to me than the lp.

Appreciate the help guys---Eric.