[skidlids]

Tonio heres my basic discription of spings

think of a spring as a leaf spring as used on older car suspension and on vans and trucks. ie a long piece of tempered steel.

If you want to make it softer you could either make it thinner or make it longer. If you then want to make it into a coil spring, think of winding it around a round former.
If using a thinner piece of steel you will end up with a coil of a certain length with a certain amount of turns.
if you used a longer piece of steel (but thicker) then you could either end up with a coil spring of the same length but with more turns and with less gap between each individual turn (care required here in case these coils are to close together and the spring becomes coil bound when the suspension travel is to much for it)
or it can be wound with the same distance between coils as the spring made from the thicker material in which case you end up with a longer spring.
Progressive springs usually rely on the more closely wound springs beconig coil bound which then effectively shorterns the overall spring length to giver a stiffer spring for the remainder of the suspension travel