Heh, you have a really good point there.
The fact is i listen to a bit of rap in the studio because i am always interested in how the bass sounds. My monitors are really tight with the bass and so its really easy to hear if its over balancing or not. Youd be surprised at how little of bass there is in rap. I find its rarely not the volume of the bass that makes it sound huge, its just really deep. Sublime, although its dub, but really deep bass non the less is one of my favorite examples. Instead of trying to put volume on it try using a bass hamonizer at about 60Hz. Even right now a boost at 60Hz and a farely large cut at 90Hz will deepen the bass quite a bit. Its the definition of that bass that makes it sound over balancing.
Whenever im doing a style like this for a client, i always to have to prove to them that this is true. They mainly comment that the bass is too low on my monitors. I just pop in sublime. They dont fully understand it, but they figure it i know what im talking about.
Also, the defined bass might also be the cause of the limp kick. 90Hz is a perfect place to boost the kick in once the bass its out of the way. Youll start to hear a defined pump in the subs between the bass notes once you do this.
BTW, do you know The Streets? I had there CD a while ago. I will need to put it in as a reference. It seems like a similiar style of music.
Danny