Join Date: Apr 2001
Location: North London, innit bruv, safe, UK
depends what gauge you're putting on. 3 springhs should be OK, but i found that if you're stringing it 10->70 (tuned a step down) then the 4th spring helps keep everything a little more solid (and is kind of needed)
You can use 4 if you want, or 3, all personal preference as to what feel you are going for.
Also, string wise, i'd suggest you go with what you regularly use, and then go with AT LEAST a 56 on the low B for standard tuning, with me leaning towards a 60 (I'd use 66, but that's if i was using 9-46)
Seems like overkill, but the extra stiffness really benefits rythm playing as it keeps it a whole load tighter, well, to me anyway.
In short, buy a couple of different bass strings, and experiment and see what's right for you!
And back to the springs, i've used 4 springs on 6 strings... It's all about what you are used to, but i do like the extra pull, makes everything snappier!