D,
One of the earlier posts was right on, IMHO. The bass starts with the right sound first. Most synth bass patches right out of the box are NOt approprate for the rap bass sound that I think you're going for. I have the Roland 1010 synth module. It has all of the sounds from
the JV80, 1080, 2080 (except without the editing - editing is done on computer). Long story short is that there are a couple synth bass sounds in that piece (and I suspect in other Roland keys/modules) that has the sound you're going for basically out of the box. If you can get a hold of one of those keyboards then go for it.
If you CAn't get a board with the magic sounds built in, then I suggest you eq a chunk out of a Moog-type bass sound out of the middle, so that the bass has only low lows (under 70Hz) and high highs (above 2-3kHz). Play around from there. The bass sounds that have it out of the box have that characteristic of having very low lows built in and some high harmonics so that we can tell what note the bass is hitting. The lows are really just for shaking the floor and providing rap "ear candy".
The mid bands of the bass are EQ'd out to make room for the vocals and other instruments. Also the kick and the bass must be EQ'd as a group. If you have the kick spankin' at ~90Hz, then the bass must be cut in this same frequency. Use the synth for the deep, shakin' bass sound. Don't have the kick real low. The kick "thump" is around 70-110Hz), below that for most kick sounds (unless we're talking about a 'drop bass' sound, which is really a synth bass) will have to much energy to be of any use (read: it will muddy things up).
What I'm proposing will not be able to be EQ'd on the Mackie. There just isn't enough parametric EQ control to properly EQ the bass this way. Either use the parametric in your computer (if you have one) or try editing the bass patch within the keyboard's effects. Surprisingly, many keyboard's have parametric eq's in their effect processors that are good enough to do what I propose.
Also, don't forget to compress the kick and bass HArd, like they insulted yo' mamma'!
Let us know how things turn out.
Rev E
[This message has been edited by Rev E (edited 07-13-2000).]