Room correction room system vs ears….

holmz , I assumed that rear ports were for low frequency but just found in my room the high frequencies sounded flat when I had the an absorption panel right behind the speaker

@kota1 - I still do not understand what you mean?

What do you mean… and how do the ports apply to the statement:

1. The panels decreasing the distance, causes the port to reinforce gthe bass more?
2. The panels suck out later reflections, and the ports have nothing to do with the brightness?
3. Or something else?

@kota I tried using absorption on the front wall in my prior home and current listening room and did not like the dulling, lifeless effect.  I use Synergistic Research HFTs instead on my cherry plywood finished front wall which apparently diffuses the sound and prevents bright or glaring sound coming back at me.   The alternative suggested by several acoustic engineers was for quadradic diffusion paneling.  Unfortunately, the required size intruded into the room from the wall 12" and too much for my room.  

@holmz , I think the ports requires a certain amount of distance from the wall. The bottom line it was simply too much absorption with or without the port. Check the :36 minute mark in this video:

I tried using absorption on the front wall in my prior home and current listening room and did not like the dulling, lifeless effect.

On the front wall (behind speakers), diffusors tend to work much better than absorbers. I have about 65% of my front wall surface coverage using GIK Alpha 4a (1d). diffusers (even thicker, the Alpha 6a 2d) work very well on the back wall (behind the listening position). I have a combination of absorbers and diffusors on my side walls, and absorbers only on ceiling.

“On the front wall (behind speakers), diffusors tend to work much better than absorbers”

+1, @thyname 

That’s been my experience as well. I have a combination of diffusers and absorbers strategically installed in my room.