Suerface Material for a liveroom-Acoustics Forum-Acoustic Fields Forum

Hi,
I have a small but nice live room without any parallel walls.
The room sounds pretty even and balanced but it sounds a bit dull. The floor is wood and the walls are plasterboard.

My question is if the sound gets brighter and more lively if I cover the Plasterboard with wood?
If so does the wood need to have a certain thickness or could I just cover it with 2 mm wood sheets?

Thanks

Christian