Ok, so after reading this article:

I've decided I would like to try and tame my low end (bass guitar) with a bit of multiband compression. The article is long, but it basically suggests using a multiband compressor to compress the low end frequencies (Specifically targetting the low B) seperately from the rest of the bass. I've had a good long search around, and i'm looking a rack unit that will allow me to do this, do they exist? So far the only solution i've seen has to be to use a seperate crossover/compressor unit. Any help would be very much appreciated. Thanks in advance.

I'm looking for a crossover + compressor in a single rack unit. Do they exist?