Originally Posted by Robert Cook
I gotta run now, but I'll get back to you late tonight to further analyze the layout of your home theater...
Sorry jtenn, I got back home last night a lot later than I had planned to! (isn't that always the case when traveling?)
First let's talk about your left & right front speakers. Earlier I had commented that it looked as though the loveseat possibly came between the right speaker and some of the viewers. If this is the case, then it should be corrected for as many viewers as possible. We'll do what we can for the viewers in the loveseat regarding sound quality, but at least make sure that there is a direct line-of-sight between each speaker and each viewer. Additionally, you may want to consider toeing the speakers inward a bit--try a few angles (including straight ahead) and stick with whatever ends up sounding the best to you (before applying room correction--the easier you make its job, the better it will do it).
OK, now for the tricky part--the center speaker. I'll be using rough estimates of distances based on what you've told me and measuring the photo of your home theater. As mentioned earlier, a horizontal 340SE should work fine for the viewers on the couch. Its vertical dispersion is extremely wide in this orientation, so there are no concerns about it being placed so low to the floor, and your carpet and rug should take care of the reflections from the floor. The central viewer on the couch will get the best, essentially uncompromised sound quality from the center, while the other viewers on the couch will be approximately 9-10 degrees off-axis (estimated), which should be well within acceptable limits for properly designed horizontal 2-way MTM centers. To get a visual idea of the effects, look at the "Vertical Response in Degrees" measurement in the second graph on the 340SE measurements page:
When the 340SE is oriented horizontally, the vertical measurements in the graph represent its horizontal response, and likewise its horizontal measurements represent its vertical response. +/-10 degrees isn't bad, but much past 15 degrees is going to be really noticeable (I can easily notice some difference at 5 degrees or less if I listened even semi-critically). By the way, this is very good for a 2-way MTM (that doesn't have the extreme tweeter offset that the 200SE and very few other speakers have)--it would be difficult to find one that is better, but it is still of a configuration that was intended all along to limit dispersion on this axis.
Now, what a vertical 340SE sitting flat on the floor would do instead is offer very wide horizontal dispersion (as shown in the graph referenced above), which is good for a center in situations like yours, but it would also place everybody at least 10 degrees off-axis vertically--the sound quality will likely improve somewhat for the viewers on the loveseat, stay pretty much the same for the off-axis seats on the couch, and become worse than before for the central seat (but not any worse than that of the other seats on the couch). I think this could possibly be a fair compromise, but we could do better by tilting the center speaker up by about 10 degrees (the front of the speaker raised by approximately 2 inches with the rear still on the floor). This should, using my rough estimates, give all of the viewers on the couch virtually uncompromised sound quality, and the viewers on the loveseat much improved sound quality--of the latter, the one farthest from the screen will be vertically off-axis by about 10 degrees and horizontally off by about 45 degrees, but the overall result should be much better than being 45 degrees off-axis horizontally from a horizontal center (using a vertical center makes a big difference in my similar layout).
As stated earlier, these are only rough estimates. If you want me to figure out more precise angles and such, including how high to raise the front of your center speaker, then just let me know and I'll tell you what distances to measure. Feel free to experiment with the effects I've described for yourself using your current center speaker. It's impossible for me to predict how significant they may be from your point of view, but for me the optimizations I've been talking about make audible and worthwhile improvements. And in my opinion, the better your speakers generally sound, the more you can hear the differences that placement and orientation make.Edited by Robert Cook - 3/11/13 at 10:47am