Coilover Preload

[08r3308]

i been playing with my coilovers and need to know if more preload on front vs back will have any difference?

does it have to be equal all round?

front is adjusted so the spring is captive and back but with 10mm difference(rear having less preload)

if i set back preload as front i can hear my spring on hard bumps but if i back off the preload at back 10mm (spring still captive) smooth ride and no noises