Hi Kevinzoe, thanks for the response! I'll try and address your points to provide a bit more info:
"How far out from the front wall is your speakers?"
The speakers are about 45" out from the front wall measured from the woofer (or 30" from the back of the speaker). I do have some leeway here and could move them out a bit more- the main reason I have them where they are is to allow enough distance to my seating position, as per Thiel recommendations to allow the drivers to integrate.
As a side note, my ears in the seating position are about 5' out from the back wall, which I have found seems to avoid a heavy mid-bass peak which occurs when I sit closer to the rear wall. This position also gives me just about 8' from the midpoint between the speakers.
"Using a resistive-type trap with OC fiberglass means you will need to make it very thick and should have a decent air space (e.g. 6")"
The traps I just made are 4" thick 2'x4' OC-703. One of them that is across the diagonal corner has about 9" airspace from the corner, and the other that is sitting right next to it on the front wall has about 7" airspace at the bottom, but it is learning against the wall (not mounted- sitting on the floor), so the airspace decreases across the 4' height of the trap. This is definitely a place I could improve on I think, and just double-up each of these traps to make their thickness' 8". Only issue would be the traps would be getting pretty close to the back of the speaker, though this may not be a problem.
"Can you add an exterior door behind the left speaker?"
This is something I had considered (in theory at least!). I can't add a door (one of the many downside of renting...can't add doors or drill holes in walls to mount my traps...not to mention one of the walls is cinderblock!), but I did think about having some sort of removable partition that I could just place when listening, and set aside otherwise. I would assume it would need to cover most of the opening, from floor to ceiling? And also be fairly thick? Perhaps I could find some sort of big wooden board and then mount a bass trap onto that, then put that in place behind the left speaker during listening?
"The reflections on the back wall can be just as damaging so have you treated the back wall yet? "
Unfortunately my back wall has a large window centered in the middle of it, so essentially the whole thing is glass aside from near the top/bottom and left/right sides. I did recently put up some drapes to help with high and mid-frequency reflections, but I am not sure if it would be feasible to treat any additional way. I did consider also having some sort of removable partition with treatment on it that I could place over the window in the area behind my head, but I am not sure how this would work... I do like your idea for diffusion back there though- I've heard this can make a big difference in a small/medium room, I've just never tried one in here.
So I am thinking now that the best option may be a combination of more broadband absorbers behind the right speaker, and maybe some sort of partition to block the opening behind the left speaker. One of the pro's of being single and living alone: aesthetics are not a huge concern, especially if I keep things removable when I have guests over :). Thanks again!
"How far out from the front wall is your speakers?"
The speakers are about 45" out from the front wall measured from the woofer (or 30" from the back of the speaker). I do have some leeway here and could move them out a bit more- the main reason I have them where they are is to allow enough distance to my seating position, as per Thiel recommendations to allow the drivers to integrate.
As a side note, my ears in the seating position are about 5' out from the back wall, which I have found seems to avoid a heavy mid-bass peak which occurs when I sit closer to the rear wall. This position also gives me just about 8' from the midpoint between the speakers.
"Using a resistive-type trap with OC fiberglass means you will need to make it very thick and should have a decent air space (e.g. 6")"
The traps I just made are 4" thick 2'x4' OC-703. One of them that is across the diagonal corner has about 9" airspace from the corner, and the other that is sitting right next to it on the front wall has about 7" airspace at the bottom, but it is learning against the wall (not mounted- sitting on the floor), so the airspace decreases across the 4' height of the trap. This is definitely a place I could improve on I think, and just double-up each of these traps to make their thickness' 8". Only issue would be the traps would be getting pretty close to the back of the speaker, though this may not be a problem.
"Can you add an exterior door behind the left speaker?"
This is something I had considered (in theory at least!). I can't add a door (one of the many downside of renting...can't add doors or drill holes in walls to mount my traps...not to mention one of the walls is cinderblock!), but I did think about having some sort of removable partition that I could just place when listening, and set aside otherwise. I would assume it would need to cover most of the opening, from floor to ceiling? And also be fairly thick? Perhaps I could find some sort of big wooden board and then mount a bass trap onto that, then put that in place behind the left speaker during listening?
"The reflections on the back wall can be just as damaging so have you treated the back wall yet? "
Unfortunately my back wall has a large window centered in the middle of it, so essentially the whole thing is glass aside from near the top/bottom and left/right sides. I did recently put up some drapes to help with high and mid-frequency reflections, but I am not sure if it would be feasible to treat any additional way. I did consider also having some sort of removable partition with treatment on it that I could place over the window in the area behind my head, but I am not sure how this would work... I do like your idea for diffusion back there though- I've heard this can make a big difference in a small/medium room, I've just never tried one in here.
So I am thinking now that the best option may be a combination of more broadband absorbers behind the right speaker, and maybe some sort of partition to block the opening behind the left speaker. One of the pro's of being single and living alone: aesthetics are not a huge concern, especially if I keep things removable when I have guests over :). Thanks again!