3 bass traps at the front of the room on the floor just doesn't work from a practical standpoint. Also, I finally got rid of the mental block that stopped me from placing a couple of the bass traps at the rear corners (this effectively means that I can't do treatment around the rear overheads). Moving 2 of the bass traps to the rear corners, to go with 2 at the front corners, has had a profound impact.
Except for a place or two, audible ringing has virtually gone away with the lessening of decay times in the bass and mid-bass. More details, especially in the highs in songs that I'm pretty familiar with in my setup. No measurements yet, but vocals for stereo are much more open (didn't realize how constricted they had been before, much more front and center now) and dialogue intelligibility for the center has seen a significant improvement. So much so that one of my girls, who cannot watch a movie without subtitles, went through almost an entire movie (Sonic The Hedgehog 2) without even realizing they weren't on. That's the kind of perceived subjective change, virtually bordering on the objective, that's a real win!
My room has needed a lot of treatment, but
these bass traps are right up there in terms of impact on SQ. Highly recommended!
p.s. Don't waste time like I did. Put them in the corners first up and enjoy better sound from the get go.