Need some advice on stereo speakers

Hi, and thanks for reading my thread. At present I have a stereo system consisting of the following; Rotel 200 watts/channel stereo amp, McIntosh Model 37 Preamp (has built in equalizer), Anthem tube CD player and lastly a pair of McIntosh LS350 speakers (1 - 1" tweeter, 1 - 8" mid and 2 - 10" woofers per speaker. Here's my question. I am not happy with the speakers. They just don't seem to bring to my ears the depth and breadth of music the way it should be heard. My tastes run the gamut from rock to soul to vocal. Can anyone recommend a solution to this problem? I'd like to stay within $1,000 if I need to change speakers. Any suggestions would be appreciated. One last point, the system is used in a very large room 20 x 30 of which 1/2 has 7' ceilings and the other half has a cathedral ceiling so there's alot of air to be moved. Thanks.