[Nanovelich]

Profile music uses an embedded Youtube Player within the browser window that makes up the profile page, from what I can tell. Normally, the volume it defaults to is the most recently saved one in the browser (whatever you normally leave it at,) but there are ways to adjust it through the API.

+1 This would be nice. An option in Profile Settings that lets you put an integer between 0-100 is the best bet for this.