My M3v3s in one of my audio only systems are driven by a new, but low end Sony Stereo Receiver with an older Sony 5 Disc CD Player - certainly not audiophile stuff. Their high end sounds fine to me - not unlike my M2s & M22s that use the same tweeter.

If it is not your source material, maybe it is something to do with the interaction of the speakers with your room. Perhaps experimenting with moving the speakers slightly - toeing in, etc - might improve things...

TAM