Manhattan SoHo is the south part of Houston St., which divides North and South of this Manhattan sector, it is popular for its galleries and outlets; now there is also NoHo.
I was told that chinese, which leave in this section, could not pronounce very well where they leave, and the main "artery" was Houston, so to indicate they were in the south part of this street they say: "Soh-Hoh, and the place took its new name "SoHo".