My old Roland E86 had a sub woofer on the bottom of the kb - maybe that's where it is.
I must admit ... even if they make a smaller, more portable unit, unless it really sounds alot better than EVERY other GEM I've heard .... I can't get excited.
Maybe it's an American thing (like Soccer) but I just do not like the sounds in any GEM keyboards I've heard so far. Sure, there are a few sounds that are ok, but on the whole - the line leaves me wanting more.