@Jim Eshelman said
" At the time of writing Liber O, Crowley gave Ye-ho-wau. The Golden Dawn tradition employed the vibration of the individual letters, and Temple of Thelema continues with this tradition: the pronunciation, for us, is Yod Heh Vav Heh. (Not waw. That's a bastardization. I think it came from English-speaking misunderstanding that the German w is pronounced like the English v.)"
The individual letters makes more sense to me. I have to add, though, as a Semitist, that the original, ancient pronunciation of the letter × was certainly the w sound. But it doesn't matter, and I think this is one of those contexts where tradition, and its development are more central to the 'correctness' of things than historical linguistics. Since the ritual was not likely performed/designed by a native speaker of Hebrew (since none existed) I will stick with what's handed down.
"With all of these considerations, I think it is far more valuable to retain it as unpronounceable that to debate its pronunciation."
That makes so much sense. Especially since * ye-ho-wau * is just the tetragrammaton with the voweling of * Adonai * superimposed on it to remind the reader what to say. Those Masoretes have sure made things hard, if not very detailed, for us!