Spelled Kalix, it becomes the name of a Swedish town. The name of the town is derived from the Kalix river, which, in turn, has got its name from the Sami word gállit, "to wade", or gálus, "cool". The form Kalix was probably inspired by the Latin word Calix.
The singer Edward Ka-Spel named his son Calyxx, which very much seems to have been derived from Calix. (Seeing this name finally makes "Calyxx" make sense to me, because, knowing Ka-Spel, Latin definitely seems like a language he'd pull a name from.)
I like this name a lot. I'm not sure what the correct pronunciation is, but I pronounce it KAY-lix. I'm sure that's wrong, but I like the sound of it. This is a very strong and interesting name for a boy.