I am curious as to how far away you sit from your Omega speakers and how far apart they are when used in room placement
I've never owned Omega speakers, but I've seen and heard a few and I've owned a few fullrange single driver speakers over the decades. Regardless, there isn't anything about Omega speakers that makes them much different from most other speakers when it comes to positioning them.
I am about to start moving mine around (again) to experiment. In my current setup I have moved the speakers a lot trying to get better center fill but have not yet been satisfied.
In this hobby, the room and room arrangement is critical to the final outcome. Time and time again I have seen this gets too little effort and attention from people who think they take this hobby seriously, so congratulations, you are on the right track.
My Super Alnico HO floor standers are about 10 feet apart and probably 11 feet from my seat. Due to room and decoration restraints the speakers are about 3 feet from the front wall and about the same from the side walls. Toe in is just enough to see the inner surfaces. I have some GIK panels behind the speakers and at the first refection point on the ceiling between the seat and the speakers. I am not able to put panels on the side walls.
If you can pull them another foot or two off the front wall, go for it. Distance from the side walls is sufficient. How close is the listening position to the back wall? Is there any treatment on that wall?
With respect to toe in, there are two considerations that determine how much you'll want. Some speakers, tend to be a little hot on top making them unpleasant to listen to on axis. Less toe in helps mitigate the top end heat but it also leads to less refinement in terms of imaging. There are some exceptions to the rule, but none when it comes to fullrange single drivers. I don't believe that's an issue in your case, so having them tilted on axis may well be preferred.
You stated your goal was to attain better centre fill. First I'll tell you a little about my arrangement and why I have it arranged as such.
My smallish room is some what unique in the sense that it has seven walls, all of them of various lengths that form an overall triangular shape. It's hard to describe, but short of a diagram that's the best I can do. My speakers (similar to yours in the sense that they are a fairly efficient point source, but different in almost every other regard) are positioned almost 4' off the front wall and spread 12' apart. They are both at least 4' away from the side walls, one closer to 6' due to the non linear shape of the room.
Now here's the real kicker, the listening position is only 8' and a few inches (2 or 3 to be exact) from each speaker. That 3:2 ratio didn't come about by some cookie cutter approach. I eschew cookie cutter approaches btw, but they are suitable as a starting point if need be.
So you might wonder how did I end sitting so close to the speakers which are spread so far apart, and wouldn't that arrangent involve some kind of a 'hole in the middle' or at least very poor centre fill? Well, I wish you could hear it for yourself. Short of a front center experience at a live event, this arrangement delivers the most realistic soundstage I have ever heard. From top to bottom, the centre fill is tantamount to everything mixed on the left and right.
In other words, there ain't no hole in the middle,
unless of course a recording contains a hole in the middle on account of the engineers failure to put something in the middle! Case in point, a few nights ago I was listening to a song called 'Soul of a Man' by Bruce Cockburn from his album Nothing but a Burning Light. The percussion is panned hard right and the guitar and vocals are panned hard left with nothing in between. The net result is a big gaping hole in the middle making a great catchy song sound like shit. The blame for that falls squarely on the dude who did the lousy mix.
Fortunately in this day and age, few recording are mixed as such. Back when multi track recording was in its infancy, this kind of mixing was more prevalent and even understandable as studio personel had to wrap their heads around this new technology, but we've come along ways since that.
So crappy mixes aside, does your current arrangement really manifest weak center fill? Don't over think this, try listening critically with your eyes closed and see if you can get a good sense of where everything is located. Closing your eyes is important because cutting off all visual input really helps the brain understand what the ears are hearing.
I composed this post on an iPad, so please excuse any spelling or grammatical errors.
