I found a great place to download a lot of songs for free.
I haven't begun to look at what songs has alot of bass or what not but I just ran across Turf Talk ft. Mossie - Bounce...it's got a good bassline off my computer speakers so try it out
I just started at the bottom and started downloading songs I liked. There is also M.I.M.S.'s entire album on there as well.