Room treatments - GIK Vs Acoustimac

Sebrof, you are correct. Thanks for catching my mistake.

Csmgolf,i stand corrected about being corrected about GIK putting wood frames around their treatments.Thanks for the verification that they leave the side borders bare for absorption as per my original post of 2-27.

As an update, I received 2 tri-traps and 2 monster panels from GIK. They cleared up the sound stage while tightening the bass response. I do not have any panels on the first reflection points yet and that may be the reason why the imaging is not as pin-point as I would like it to be.

Can someone please suggest why people add panels behind boxed speakers? Does it help in sound stage? My mid-range is terrific and I love it. I want to get my system to a point where even when I move my head from the center position, the vocals should still appear to come from the middle. Is this possible? How should I decide between diffusion and absorption?

Very interested in the answers to Milpai's question too.

Hi Milpai,
* congrats on the GIK investment - glad to hear that the 4 bass traps are helping.
* lateral reflections from side walls tend to pull imaging in the direction of the reflection, so with no side wall 1st reflection absorbers or diffusers it's no wonder you don't have the tight and narrow imaging. Toole's research showed that unless you were a musician or product reviewer, that most folks preferred the side walls being bare to widen the apparent sound source.
* panels behind box speakers: it could for several reasons. Bass traps are usually most effective in corners, including front wall corners behind box or other kinds of speakers. Also, reflections from the front and back walls are less advantageous than from other directions. Placing a panel - absorption or diffusion or angled reflection like I use - on the front wall will help prevent flutter echoes between the back wall if it is a hard surface and parallel with the front wall. Moreover, placing a panel on the front wall closest to the speaker is to reduce comb filter effects, which Toole's argues is less troubling and not as auditory as a measurement graph or some people would make you believe. Lastly, I have found some absorption on the front wall deepens the apparent sound stage depth, at least in my room.
* by saying you want to be able to move your head to the side and still hear the vocals as coming from the middle/centre, then it sounds like you want a wider sweet spot, which I would think would benefit from side wall diffusion at 1st reflection points to widen the apparent sound source width, which contradicts your earlier desire for a tight image . . .
* deciding between diffusion and absorption at the side wall 1st reflection points is a matter of personal taste and goals. If the room already is 'dead' sounding, then diffusion or reflection ought to be considered. Also, do you want tight narrow imaging or broader more real-to-life imaging which loosely translates to being in the recording studio or having the musicians in your room, respectively.

Good luck and let us know how you make out. Oh ya, get an acoustical measurement tool to help you, otherwise it is just guess work.