ardour 4 32 bits

is Ardour 4.0 for linux downloadable even for 32-bits hardware? thx

Yes. Choose x86 for 32 bit, x86_64 for 64 bit.
It’s all plain to see on the download page at http://ardour.org/download.html (or the Download link on the nav menu here)
Similarly for Mac OS, 32 or 64 bit.