Sound/weight relationships are very qualitative. And the end result definitely depends on more factors than just weight - although wood is definitely a major player. For instance, my P-bass is light alder but doesn't sound thin. I honestly don't know enough about it to make claims on what does or doesn't work.
A light(ish) alder '51 style P bass is an example for the same, that I could cite too.
Mind weighs in at 3.5 Kg and really is not thin sounding at all.(I compared it with a few basses similar to it although all had ash bodies and most had maple boards whereas mine has a rosewood one).

