OK, my project today is to use REW/ETC to hunt down some pesky remaining reflections, and I need some advice from our reflections experts (Jim
My approach is to use the "Blocking Technique", employing a spare 2'x4' acoustic panel to narrow down the direction of the unwanted reflections. Let's start by looking at a nasty reflection associated with the center channel:
Here is the result of placing the blocking panel behind the listening position:
Looks like I have found the source! It is the back wall. This is where I need some advice. I have a rather narrow back wall section, the rest being open to the rest of the ground floor. Here are pictures:
And with the blocking panel in place:
Note that the entire back wall is already covered with GIK Acoustics 242 panels. The placement of an additional panel seems to alleviate the reflection that must be coming from the 242 panels themselves. But how could a 242 panel be causing a reflection? Is it because these panels are ineffective?
Now let's look at the right front speaker:
Now with the blocking panel behind the seating position:
Once again, the additional absorption on the back wall seems to alleviate the reflection, indicating that the 242 panels are not doing a good job.
So, advice needed. What to do about the ineffective 242 panels? Replace them? Ask for advice from GIK?
For the time being, I am simply going to leave the extra panel in place. It isn't pretty, but the additional absorption is effective.