How to set your bass up for really low tunings
 

yesterday I was playing around with some tunings and I liked B standard but the strings are way to loose and buzz if I try to pick in that tuning. I'm new to bass setup (I normally have it done when I buy a bass). What would I have to do to play this tuning smoothly?

Get a set of 5 string bass strings, throw out the G. The strings will sit a bit higher unless you file down the nut, which I would really think about for a long time before I did.

Using the bottom 4 strings of a 5-string set is a common and very workable idea. However... if you try to use a gauge string that's larger than the corresponding nut slot... especially the outer two strings... that's a recipe for a cracked nut, not to mention much higher action.

Very true. I mentioned filing the nut to accommodate, but doing so is permanent, hence thinking about it. I should have mentioned the down side to putting those strings on without filing the nut. My bad.

To the OP, if you don't want very floppy strings, you'll need a much thicker gauge than typically comes on a four string bass. If you want to use, say, .110 or even .115 gauge E strings tuned to B, they're still going to be quite loose. You will need to raise your action significantly and adjust your truss rod a good bit.

You could always get a 5 string bass and solve this altogether as well:D