Wirelessly posted (Opera/9.80 (BREW; Opera Mini/6.0.3/27.2354; U; en) Presto/2.8.119 320X240 LG VN530)
Yea, voice would be just 59, since the T is dropped. I don't know where exactly 5x5 came from, but, IIRC, I've just seen it refered to as being an old phrase meaning loud & clear.