Lots of bass at walls, lack of bass in center of room/listening position


I guess this is relatively common in listening system. Is there any way to smooth this out so I get more bass energy at my listening position? This happens with our without my 2x 18 inch subs. Room is 12 x 16 x 8 ft, speakers 4.5 ft apart on long axis and I am sitting 4.5 feet away. I tried moving back and forward but the entire middle center of the room except near the walls has decreased bass.
Is this a boundary effect or could it be due to bass cancellation effects?
smodtactical

Showing 2 responses by golfnutz

If you're thinking about Acoustic Panels, you should consider making them yourself. The Rockwool Comfortboard 80 from Home Depot is as good as anything out there and it's only $58 for 6 pieces. It's very rigid, so you don't need to treat it at all. Check out the Acoustical Performance here -  https://www.rockwool.com/products/comfortboard-80/?selectedCat=comfortboard%E2%84%A2%2080%20downloads#Specifications&Sizes
For Bass Traps, just double up with 2 pieces for 3".
All you need to do is build a wooded frame, add the Comfortboard 80, and staple some Guildford of Maine FR701 cloth on it (about 5yds), which you can order from Duvaltex in Quebec. I added Cambric dust collection fabric to keep any loose particles intact, which is very cheap to buy (use 3M 77 spray adhesive to glue it on over the Comfortboard 80). Anything you buy won't be better than making your own.
Yeah, I saw the recycled denim stuff, but it didn’t appeal to me. It just didn’t look rigid enough for what I wanted.
Actually, I glued, then used a brad nailer to secure the frame. Using glue and finishing nails would work if you don’t have a compressor.
Don’t overlook the Cambric material and 3M adhesive spray. It makes a difference. You’ll save money by not having to cover the back of the panels with Guildford of Maine cloth. I wrapped the entire batt with it (cambric material).
You could see if Home depot will cut to size and deliver, but you need to order the right wood. If you go there yourself, you can pick the best pieces (straightest, and less knots). They’ll cut it for you there as well.
Something like this for the walls or ceiling (lumber edges are rounded and smooth):
https://www.homedepot.ca/product/thd-generic-1x2x8-framing-lumber/1000173739
For 3" for Bass traps you could use this:
https://www.homedepot.ca/product/thd-generic-1x4x8-millstead-spf-sdry/1000100188
You’ll probably want some D-rings for hanging them. Each panel will weigh almost 10 lbs (over 20 lbs for Bass traps), so I used these - https://www.homedepot.ca/product/ook-large-2-hole-d-ring-hangers-value-pack-10pcs/1001027224