Some thoughts on what I would try:
Check out ATS Acoustics web site for DIY products. This just as an alternative to GIK (not suggesting better than).
Find yourself a pair of standmounts that roll-off below 50Hz.
Place speakers on short stands and angle upwards.
Place absorption panels behind speakers, at 1st reflection points on sidewalls, and behind listening position. Panels need not be larger than 2 x 4 feet.
Bass traps in corners. Start with front.
Use wall-to-wall carpet with pad.
Place equipment rack beside listening position, place nothing between speakers.
Check out ATS Acoustics web site for DIY products. This just as an alternative to GIK (not suggesting better than).
Find yourself a pair of standmounts that roll-off below 50Hz.
Place speakers on short stands and angle upwards.
Place absorption panels behind speakers, at 1st reflection points on sidewalls, and behind listening position. Panels need not be larger than 2 x 4 feet.
Bass traps in corners. Start with front.
Use wall-to-wall carpet with pad.
Place equipment rack beside listening position, place nothing between speakers.