Try moving forward all three front speakers as much as possible.
Add acoustic treatment, foam, pillows, wall rugs etc... directly behind the three fronts. The center is probably the worst problem with the brick. Hunt around the house for anything you can experiment with.
Try turning your center channel 90 degrees on end. Keep the center tweeter level as close to the L&R speaker tweeter heights if possible. This will give you wider dispersion horizontally and less dispersion vertically. Tilt the speaker so it is aiming at the listening position.
You may need to tweak your levels after each experiment.
On the first reflections I have a plush couch/love seat placed. Not sure how much this really helps. The floor is carpeted. Behind the TV smack in the middle is a brick fireplace.
I've always said a TV smack in the middle can't help anything. Projector would be the only solution for that, spendy...
Maybe this is too obvious, but in just about every setup I've heard with a TV between the speakers, there is very little or no depth -- no matter how good the speakers might image otherwise. The glass seems to kill any chance of creating depth. I noted this in several installations at this year's T.H.E. Show in Vegas. Same products, neighboring rooms: The one with no TV had depth for miles, the one with a TV had none.
You might want to consider room reflections. Are your side walls damped - at least where you have the first reflection of sound. What is on your back wall - I suggest damping it also. Do you have carpeting - If you are getting reflections off the floor and ceilings - not good. All these things, as well as, speaker placement affect imaging and depth. Too much damping and you may lose a little on the higher frequencies. If that is a problem, try using something that will diffuse the sound versus damp it. Good luck and enjoy!
Depending on what a client is willing to do, we can basically flatten the response of any room, widen the sweet spot and even the decay times. This is hard particularly in small rooms, but it can be done. For rented spaces it's a little more limited, as you really can not do the serious construction to fully optimize a room, but there is a lot you can do.
In general EKG graphs are not what we're looking for (unless the person is dead--then that basic flat look is a good thing for audio). Can you e-mail me your graph and a drawing of the room? Even better would be to download the application form and fax it to me along with the graph. The form can be downloaded here. From that I could give you a very good idea of what could be done without the use of permanently installed devices.
Rives, I was going to list everything wrong with the room, but to same time, the only thing not wrong is I don't have a bay window. :) Being that I'm renting, I assume the dedicated lines was pushing things, not really sure how much more I can get away with.
Thanks for the input, I have measured the overall room response via your test cd. It should look like a ekg, right? Guess I should figure out how to straighten that graph out.
Side question: I assume you have gone into a setup with the response all over the graph. How much of a difference did it sound when you did your thing.
Well, I'm always the "room could be the issue" kind of person. It's an occupational hazard. The room and speaker placement in general are the two things I would look at. Please visit our website Rives Audio and go to the listening room. It is a tutorial section and if you click on the speakers there is a white paper we wrote on speaker placement. The other area to look at is overall room response. Reverberation times and damping in a room for HT vs 2 channel can be quite different. In my room I optimized for 2 channel and the HT is certainly not as good as it could be, but if your room is optimized for HT, then it doesn't surprise me that the sound stage really isn't there for 2 channel listening.
You may want to experiment with toeing in the speakers a bit if your system is sounding flat. My system benefitted by doing this. Toe in the speakers in small increments at a time. I hope this helps.
