Bass trapping - corners or walls?
As fate would have it the standing waves associated with room corners do not (rpt not) always manifest precisely in the corners. That’s why it’s a good idea to map out the standing waves using a test tone and SPL meter. You may find in some cases the standing wave is located a foot or more from the actual corner. Placing the tube trap in the precise location of the standing wave makes all the difference. In addition to the corner locations, there usually are other places around the room where a tube trap is beneficial such as at the reflection point on side walls. |
Your room will have bass nodes at different frequencies and spots. Some of these "room nodes" will be loaded on the left/right side walls. Some will be loaded on the front/back walls. Others can also be loaded on the floor/ceiling points. However, putting bass traps in the tri-corners of the room (such as where floor meets back wall meets side wall) will treat all three types. It's a good compromise unless you need to specifically treat a certain frequency more so (in my room there is 50hz node loaded on the side walls, so I put 50hz membrane bass traps on the side walls to help). @handymann - try using 703FRK panels instead of normal 703. The foil cover on the FRK will reflect the mids/highs and will not suck the life out of the room as much. It will be a fine-line balancing act. Too much FRK panels will create brighter and harsher highs. Your normal 1" 703 panels will do absolutely nothing to treat the 30-150hz areas. The FRK foil panels will actually work well in treating frequencies down to about 80-90 hz. The foil cover on the FRK will act as a "membrane" and will resonate to the 80-150 frequencies. The fiberglass behind the foil will absorb the energy from this resonation and you have a nice 80-150 bass trap. Anything below 80hz really requires a tuned membrane type bass trap (such as the GIK Scopus traps). your 19x21x10 room appears to have 3 significant nodes at 53hz, 56hz, and 59hz: https://amcoustics.com/tools/amroc?l=21&w=19&h=10&ft=true&r60=0.6 An idea would be to contact GIK Acoustics and have them make some custom T55 Scopus bass traps (figure on about $1,000 for four traps). Them put them in the four tri-corners of the back wall. That should really help treat the 50-60 hz area. You have two other nodes, 80hz that load on the front/back walls, and 88 hz that load on the left/right walls. You can probably treat these with some 2" 703 FRK place in the rear corners maybe just on top of the Scopus on the floor. |
@handymann - alternatively, you can make your own tuned membrane bass traps. Requires some woodworking (sealed box) and neoprene rubber sheets and some acoust-a-stuff. I can help advise on design of this if you want. I have made two sets of tuned membrane (one pair at 50hz and another pair at 63hz). They are very effective and work better than any other broadband type bass trap. The thick GIK soffit traps really don't do much here. I have even tried Helmholtz resonator boxes and they didn't do much either. |
