Like Glancebam said, the volume is not much to brag on, but it's still loud enough for at least the majority of calling stands, especially at night time. I think people tend to call way too loud in most cases anyway. I rarely run my Fox-Pro at more than half volume. With most stands I run it about a third or less.
A friend of mine uses one. I've been out with him, and the sound "quality" is actually pretty daggone good to be priced as reasonably as they are. He's killed several coyotes, and foxes using his.