Sayhi5,
I think you need a strategy, one of which may be:
* Problem Identification - first use a SPL meter and test tones to isolate the offending bass mode frequencies. These test measurements across a wide bandwidth should be recorded in say an Excel spreadsheet and will become your 'baseline' from which to compare alternative speaker-listening position changes and the addition of acoustical treatments
* Moving Speakers &/or Listening Position - try putting your listening chair 38% of the room's length away from the back wall, assuming your speakers fire down the length of the room. Take measurements and record them. Try moving your speakers to 1/3 the room length away from the front wall - measure and record. Try moving your speakers closer together so that they are farther away from the side walls and toed in 30degrees.
* Bass Trap Placemnet - assuming you are like most folks and opt for the low cost fiberglass filled traps, their effectiveness is maximized when pulled out from the wall a distance that equals 25% of the offending frequency. For example, if the problem frequency is 100Hz then the front of the fiberglass filled trap should be out from the wall 33.9" (1130/100*12*0.25). Consider this a starting point for experimentation because walls with doors or windows cause that room dimension to be longer for acoustic purposes due to less rigidity. So if you have a door on the long wall then the width dimension will likely appear acoustically longer than it actually is, so experiment by starting at 33.9" and then moving the bass trap closer to the wall in small increments - measure and record each move. Try the bass traps in all four room corners from floor to ceiling and also in the middle of the front or rear wall.
* Buy VS Build (DIY) - building bass traps is pretty easy and is less costly than commercial products, but to each his fancy. I've built hemi-cylindrical diffusers and filled their cavity with OC 701 to act as a bass trap. This does two things - traps bass and prevents mid/high freq absorption so as not to over dampen the room. Just a thought . . .
good luck. let us know how it goes.
I think you need a strategy, one of which may be:
* Problem Identification - first use a SPL meter and test tones to isolate the offending bass mode frequencies. These test measurements across a wide bandwidth should be recorded in say an Excel spreadsheet and will become your 'baseline' from which to compare alternative speaker-listening position changes and the addition of acoustical treatments
* Moving Speakers &/or Listening Position - try putting your listening chair 38% of the room's length away from the back wall, assuming your speakers fire down the length of the room. Take measurements and record them. Try moving your speakers to 1/3 the room length away from the front wall - measure and record. Try moving your speakers closer together so that they are farther away from the side walls and toed in 30degrees.
* Bass Trap Placemnet - assuming you are like most folks and opt for the low cost fiberglass filled traps, their effectiveness is maximized when pulled out from the wall a distance that equals 25% of the offending frequency. For example, if the problem frequency is 100Hz then the front of the fiberglass filled trap should be out from the wall 33.9" (1130/100*12*0.25). Consider this a starting point for experimentation because walls with doors or windows cause that room dimension to be longer for acoustic purposes due to less rigidity. So if you have a door on the long wall then the width dimension will likely appear acoustically longer than it actually is, so experiment by starting at 33.9" and then moving the bass trap closer to the wall in small increments - measure and record each move. Try the bass traps in all four room corners from floor to ceiling and also in the middle of the front or rear wall.
* Buy VS Build (DIY) - building bass traps is pretty easy and is less costly than commercial products, but to each his fancy. I've built hemi-cylindrical diffusers and filled their cavity with OC 701 to act as a bass trap. This does two things - traps bass and prevents mid/high freq absorption so as not to over dampen the room. Just a thought . . .
good luck. let us know how it goes.