Setting the range is possible, but I suppose you want to enforce the range as well, right?, so that it it not possible anymore to move a value outside the array box with the mouse?
it was just to set the range, but as I said, I didn't looked at it closely
enough. now I know how to do it.
This indeed is not possible to enforce with Pd, however I don't see why this should have anything to do with arrays being designed for audio data. Arrays are not thought to be for audio data only, they are general purpose, well, arrays.
that I also wrote too fast: of course an array is just an array. I meant
to say that since arrays have as standard the boundaries between -1 and 1,
it is more common for them to be used for audio. but of course, we're in a
democracy, an array can do what he pleases.