Roofing felt, fiberglass batt,
@BIGmouthinDC I have seen you recommend this method several times, and also placing the riser on top of a (decoupled??) sub floor on top of the slab (layer of rubber followed by layer of plywood). I think you have mentioned horse mat for the rubber layer. Can you comment on the benefits of that subfloor (improved sound isolation? better audio acoustics?). Might be something for the OP to consider.If you are not adding a source of vibration to the riser there is no need to decouple the riser frame from the concrete other than the roofing felt. If you were adding Buttkickers you could build the frame on rubber Uboats. The felt allows you to use regular lumber instead of PT since the wood will be in contact with the concrete. It also keeps moisture out of the insulation
There is diminishing returns of filling up the last 30 percent of the riser if you are not using it as part of your resonant frequency bass management plan, frankly you probably should with the size you are planning it can make a difference. So in your case of not doing that just get the thickest fiberglass batts you can find and do one layer
Multiple layers of decking with ether Green Glue or roofing felt between layers is al about keeping the deck quiet when you walk on it, I normally do 2 layers of 3/4 OSB or Plywood. Some pro plans I’ve built had 3 for a total of 2 inches,
I am happy to consider making this big riser part of a Hemholtz resonator if that is what you are speaking of. My only concern is that although I have read some stuff, it sounded like you pretty much needed to know what you're doing to make sure you are getting the correct frequencies. If there are some general recommendations, I am all in for considering this.if you are not using it as part of your resonant frequency bass management plan
Thanks for the link. A few questions as I get ready to order:yes, yes this is my source of vents pretty much any size is available if 48 doesn't fit. HVACQuick - Dayus DABL and DABLD Bar Linear Grilles - Made to Order
If using the Riser as bass absorber you want to frame it as one connected air space. Here is one way, gap under each joist.
View attachment 3135822
Thanks for the specifics. Looks like total cost is a little over $100/grate. Doing this will pretty much take care of my bass management, correct? (I am doing your recommended linacoustic/3mil/linacoustic behind the screen wall too and then go from there as far as other absorption/diffusion). If so, I am guessing this will be at least as good or possibly superior to putting in corner bass traps and less expensive and obtrusive as well?Standard, I order the the screw attachment method and set them in place without the screws, gravity takes care of the rest.
blade 0 degree
If you stick with 4 inch wide you do not need the floor option as your feet span the grill and don't exert much pressure.
Well you need to make sure your ears aren't in a null, 25, 50 and 75 % of room length for room length issuesDoing this will pretty much take care of my bass management, correct?
Thanks. Got everything in the cart. OUCH! $460 (black powder coat added about $30/grate and was $45 shipping)Well you need to make sure your ears aren't in a null, 25, 50 and 75 % of room length for room length issues
that you use two subs equal distant to the center line of the room for room width issues if you have center seats
and that you have some way of doing measurement and equalization of the room
then you should be good.