kinda late in here but a general question. if a speaker plays classical music well would it not be good for all types of music minus perhaps how low they can go.
In theory, yes. But when you consider the finer points of practical use, then the answer is: not necessarily.
I pointed out earlier that the human hearing system tends to perceive easiest, the longest delays/reverbs, whether these are from the room, or from the recording. With the minimum set up of a true wide band omnipolar speaker in a normal room, significant room delay/reverb will be present. Now, this can be minimized to work well with all music types, but it's not likely in what amounts to casual placement of the speakers with little to no acoustical treatments to specifically address this issue. In the original posters circumstance, his set up is going to have significant delays that will be of negative consequence when the recorded music has very short or no delay/reverb. Now, the original poster wants to primarily listen to classical music. Nearly all of such music has substantial delays/reverb as a consequence of the recording environment(s) typical for this music genre. As such, this would dominate the perceived playback, with the room signature delay/reverb with much shorter time window would be heavily masked. Now, if you play back studio recorded music with little to no delay/reverb(rather common on present day pop/rock/etc.), the room is going to become far more audible, most likely to an annoying extent. In addition, most omnipolar speakers have substantially lower output SPL ability as compared to monopolar speakers - there for if one likes to listen at moderately high SPL - the speaker's mechanical limitations, and even amplifier limitations, may become an issue.
Now, one could have large broadband absorber panels and perhaps some diffusors to put on the side walls, and set these up behind the omnipolar speakers to remove the rear reflection(s) for low delay/low reverb music, and avoid many of the room problems. Then take down these devices for classical music or other music with heavy/long delay/reverb. If one is willing to do this, them they could have the best of two worlds. However, one more factor enters here: treble power. With an omnipolar design, the treble will usually be reduced in level more, as compared to a monpolar design, as the amount of total radiated power in both circumstances is radically different in proportion with the midbass band. The correction for this would be to add a shelving filter to the line level signal to boost/reduce the treble power for each mode of operation. A digital DSP EQ would make this a simple/easy adjustment.
-Chris