The speaker actually sounds good and is clear and loud,(there is only one speaker so its not in stereo) great for background music at home and just loud enough to rock out at work at your desk. The sound is great but lacks any bass. 
as far the lava goes it takes about a hour for it to heat up to create the lava effect but once it heats up the effect is pretty cool. You can use the just the speaker without the lava light if you want.