What program would you guys say gives a really deep and heavy bass drop kinda like the one at 0:16 in this song http://www.youtube.com/watch?v=0RGpAvWqctQ

I tried subatomic but it really lacks power and it seems to lack a lot of depth, but i have little to no knowledge in electronic music so if anyone could explain to me how to better utilize subatomic or know of a better program (free preferably) that would be awesome. Another great example of the sound i'm looking for is the bass drops in skrillex's with your friend (long drive remix) at 1:46 of the song. Sorry if this is in the wrong forum.
You can do it really easy in audacity (its free). Just press generate Chirp then you just choose starting and ending Hz and how long you want it. Theres some other settings too, I just play around with it till i find something nice