these sites could be worth having at look at:

http://www.acapellas4u.co.uk/forum/

or

http://www.acapella-heaven.com/ib/index.php?act=uportal

it reads:

Newbies, please read!!

To gain access to the downloads, you must first make 25 posts in the forums.
BUT!!! if you spam the board with useless threads/replies, your post count WILL be reset back to 0, and you WILL be banned for at least 24 hours.
DON'T LEARN THE HARD WAY!