height to hand absorption foam panels


My ceiling height is standard 8ft. I have determined how far down each wall to place the panels using the well documented mirror method. I have 24" X 24" , 4" thick panels I purchased from Silent Source, model is called hush foam. I will be stacking the panels vertically, essentially ending up with 48" H X 24" W, for each side reflection point. I will be treating both the first, and second side reflections, employing 8 panels total. My question is should I hang them so that they meet at the tweeter. This would then have me covered 24" above, and also 24" below the tweeter. Just looking for the audiophile rule of thumb for this. BTW on a side note, also have eight additional panels that I will be using for the ceiling first reflection. Any advice there would also be appreciated. I figure the mirror method to determine the distance from the speaker, but then how about width placment. The room is 12 + feet wide. BTW, I use RPG diffusion panels behind the speakers, so I do mix it up a bit. These are the larger 4ft X 4ft wooden ones.
fjn04
I agree with your plan provided you sit with ears at tweeter height. I would caution about over doing mid range absorption - a lively sound is not necessarily bad if you can keep the speakers at least 3 feet from side walls. Bass traps are usually the most needed.
Thanks Shadorne. My 12 foot wide room does limit the distance I am able to place my speakers from the side walls. I am now about 2.5 feet out from the side walls, which really only leaves for a seven foot spread. All these measurments are from center driver. I do have a live sounding room. I am no acoustician, but I hear quite an echo after clapping for instance. Hopefully, these panels will even allow me to place my speakers another half foot or so closer to the side walls. Certainly it will be nice to have more options anyway.
Don't move your speaker after you place the treatments at the reflection points unless you also move your listening position to get back to that same reflection point. So get the speakers placed first where you want them, IMO and IME. (BTW, I would move the speakers farther away from the side walls. Have you tried placing them 1/3 third of the way into the room and then move them out until the soundstage looses focus?) The absorption panels will help with the slap echo, but I have found that the best treatment spot for this effect in my own room is in the corners and all wall/ceiling boundaries.

Everything I have researched says it is near impossible to have too much bass trapping in a room, as long as the treatments are also designed not to absorb higher frequencies. I believe this means that to get to an over-damped sound you would have to start killing the frequencies about 1 or 2kHz, so research the treatments you are going to use. It is usually easy to prevent this from happening.

Also, check out the acoustics forums on AA and AudioCircles. Free advice from the Pros there!