Horning Eufrodites - help needed with boomy bass

I've been trying some of the suggestions you guys have gathered for me, the stacked wood, some polyester stuffed, some more positioning, a large painting on the corner created by the little wall on the left to break the 90 degrees, etc.
so far, nada.
the boominess is there at all cases, sometimes it's even worse, except for those two pillows that were very strongly pushed into the ports but that have also significantly reduced the dynamics and extensions on both ends of the music.
tonight I have here a Karan KAI180MKII integrated at home to listen to a little but even though I can tell there's more control in the bass department, it's still boomy, and still the left side is the more boomy part of the room.

the best "proof" of the bomminess is my 6 years old daughter who walks in front of the speakers, while playing softly, and says "it breaks my ears".

bottom line, frustrating.

spiritofmusic, yes, this thought has crossed my mind but a) I think these speakers setup right really play lovely music. b) the last thing I feel like doing now is selling/buying etc namely in the current economic mood here in Europe.
so I'd rather try anything possible before giving up on these.

what's next?

thanks again for the help from you all.

Time to give bass traps a try, you have nothing to lose.

There are various forms of digital or analogue bass equalizers that can greatly reduce bass booming. Since this is a very serious problem for you, this approach should be considered even though it is anathema to a "purist" approach. This is much more of a certain cure than any other cure.

yap, swapped speakers left/right a while ago. today also the thought came to me that maybe the dual mono of the amp is to blame so I swapped the outs from it too... niente.
I thought the painting is probably too light but that's what I had...

irrespective of, this Karan integrated, brand new out of the box, is playing very nicely.