Corner Basstrap Construction
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This project is a credit to Tom Skeahan and Ethan Winer at the musicplayer acoustics forum for their great advice and inspiration. they know what they are talking about...the method is simple and it WILL give you more detailed imaging, a bigger soundstage, and a flatter low end response. Your mom wouldn’t notice the difference but you will.

To save Tom & Ethan from saying it again, i will echo their words: it is all about ‘coverage.’ In other words, the more traps you install, the flatter the critical low-end frequency response of the room will be. more is more.

If you don’t want to DIY, RealTraps are the way to go. but here’s how i did it.

   
Corner Basstrap Construction
1

corner, pre-bass traps.
notice the, er, lack of bass traps.

ready your masks, gloves, and longsleeves

....and warm up your screwguns

(don’t even think of working with this stuff without at least a paper facemask and a pair of gloves

2

parts needed: not much.

2 ½” coarse thread drywall screws

fender washers (1/4” hole, 1” or larger diameter)

carpet-cutting knife with a long retractable blade (not a box-cutter)

....and a bail of 705 rigid insulation. some people use a kind of rockwool. if you need a source in the new york city area, email me (below).
3

1. use the long blade to miter the whole side of insulation into an approximate 45° angle. cut off the smallest triangle possible to maintain the longest panel size.

2. push a drywall screw with washer THROUGH the panel, toward the wall, at an angle that will grab mostly insulation. you want the screw to hit the wall when about ½” of screw left sticking out.

3. screw in that last ½” into the wall and your panel is secure.

4

with the 9’ ceiling in my studio, i was able to easily stack 4 panels horizontally like so. to save space, many people stack 2 panels vertically instead. both ways amount to 8’ of panel height of course, the horizontal approach puts more depth, or coverage, behind the panels. do whatever your space and budget restrictions allow.

i’ll show you what the small, pre-attached pieces of plywood are about in the next ste

5

this part is optional and sort of out of order. it should really be step one. since room corners are havens for bass buildup i wanted to double-up the lowest and highest panels in my corners. my method involved pre-attaching small pieces of plywood to the first ‘inner’ panel using an additional drywall screw & fender washer, BEFORE screwing it into the wall.

left photo shows the inner panel side that will eventually face the wall, and the right photo shows the side (with the plywood) that will face the room. the plywood will give our second, doubling-up panel something more solid to screw into, and it creates a bit of a gap between the panels as well (i don’t think the gap is acoustically significant.)

any method to attach two panels together to bring about a 4” thickness would work. another approach would use 4½” machine screws through both panels, with a fender washer at both ends, secured with nuts.

6

they say it is good to fill up the corners with any spare insulation or foam that you may have around.

7
i screwed in the second, outer, panel of 705-FRK (foil-reinforced Kraft paper) into the plywood of the first, inner panel....
8

...and i didn’t miter the edge. of course, if you want everything to be flush to the wall, you would miter every panel on 45° angles with the carpet knife, and cut the inner-most ones a bit short across the long edge.

so then attach the next panel above the first as in step 3. the area behind the traps does not have to be sealed, i.e. vertical gaps between panels have no acoustical significance.

9
use cutouts to avoid existing objects....
10

can you tell that i doubled up the upper panels near the ceiling as well...

11
proceed to cover the whole vertical length of your newly mounted panels with fabric, and install moulding trim to hide the fabric edges, and you’re there.

questions are best asked on the musicplayer acoustics forum however feel free to email me.

happy DIYing...

mark
new york, usa

 
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