Magnets for an 8 string P90 style pick up

[jason lollar]

What would be the effect if the magnet on one side went to one end of the bar.
Let the magnet on the other side of the bar go to the other end?

thats how gibson did it- you can read there is a difference in strength at the poles with a gauss meter but it doesnt seem to make enough difference to be obvious- I have made hundreds of pickups that way and they all worked fine.

[Mike Sulzer]

If you use a Keeper bar how many magnets would you try.
Could you not place 3 on each side of the keeper bar in a staggered pattern?
B_T

You could; should work well. Or you could put one small one corresponding to each string in each side of the bar. Lots of things to try and see what works best. David has discovered that you can use pretty big neos on a bass pickup, I believe (less effect of string pull with heavy tight strings), but you have to be careful not to get too strong with a guitar.