I've always thought that dealing with an issue directly rather than indirectly, when possilbe, was a good idea, for instance dealing with room issues by treating the room, as we see Jimna has done.

Recently I noted this video on YouTube. There is a dark-colored square horizontal surface with a light colored sediment sprinkled on it. The surface is stimulated by a slowly rising audio frequency. The sediment tends to settle where the surface vibrates the least and leaves the most active regions largely devoid of sediment. It is a wonderfully visual demonstration of standing waves on a surface memabrane which is very much like standing waves in a rectangular room.

Science Fun on YouTube << (click link)

The patterns are in some ways facinating. Take a few moments to pick one spot on the surface and note what happens at that spot as the frequency changes. If at one frequency that spot is covered with sediment while at another frequency that spot is in the middle of a dark zone, that would be like a point in a room where one frequency is nearly nulled out while another frequency may be heard four or more times the sound pressure level. Now imagine the surface is vibrated at six different frequencies at once. Depending on where one would wander within a room with strong standing waves, one might have a greatly varying listening experience.

Now note the very beginning of the video, say from two seconds to four seconds in. The sediment is beginning to show some variance in coverage, but except for the edges and corners, there are no harsh demarcations. If a room can have most of the standing waves greatly reduced, then there may be some gentle variance among listening positions, but nothing too drastic.

Enjoy.