Stirling...

Can't do it in less that 3 words....... you adjust the skin (if it is too loose or tight) on a non tunable by adding water or heat to the skin... if you add water you won't really notice a difference for a few minutes, and you may have added too much.....

with a tuneable you adjust the screws and the result is instant....

that is the major difference... plus you can tune it if you want so that your drum is in the right key....

Slainte

alison