advice and help for setting my bass up in drop A#

[WarofAges]

I have been paying in this tuning for about a year, and have been struggling to keep my bass set up the way I like it.

I've tried alot of gages of strings(including a 5 string set and just used the low 4) and I just cant get my bass playing the way I like it, and the guitarists are set on the tuning, and they dont understand how much time you have to put in to setting up a bass for dropped tuning.
FYI my bass is a Fender Deluxe Active MIM, its a great bass and i love it, i used to have it set up in Drop C in my old band and it played great. I picked up a Fender MIM 5 string for 200 bucks, and ive been playing that more cause I didnt have to adjust anything going from B E A D G tuning A# F A# D# G#, but i dont like playing 5 strings at all, and i dont use the G string at all.

Can you help me? No matter what I do, I cant get the neck set up the way I want it, the strings are always going to buzz unless I have an unplayably high action.

[tom once dead]

I dont see why using a string set didnt work.

what dont you like about it?

[WarofAges]

what dont i like about playing the 5 string, or why i cant get my 4 string the way I want it?

I dont like the thick neck on my 5 string, ive been playing Ibanezs for years, but i like the jazz basses better.

My active jazz bass I just cant get set up the way I like it. Even when I have the neck set up right, the frets above the 12 fret always buzz, then I have to raise the strings to get them to not buzz, then I have a high action that I dont like.

I think I have the most trouble with the neck. Every time I take my bass to a luthier, they either screw it up, dont set it up the way I want it, or do bunch of other stuff I didnt ask for and charge way to much.

I do have a shim in my neck cuz i put on a leo quan BA II bridge.

[JustDavid]

What's the neck relief amount?