What the *#$@ happened??

I'll keep this short, just hoping someone can let me know what's going on. I changed out the platform my TT was on to a much denser wood, and I'm not really happy with the results. The good, I can hear more detail in the music, subtle nuances are more prevalent, better instrument separation, especially in complex arrangements. The bad, the whole stage moved back and got flatter, it lost depth. And the 3 dimensional characteristics of the singers voice also lost luster, became flatter as it were. It almost seems like I'm listening to a stereo now instead of a live performance. I thought the heavier wood would improve the sound, not degrade it. 
Anyone know why this happened?