How can I make a soundcloud block protected from copying to stop use outside of a members area?

Site URL: http://infinite-crescendo-new.squarespace.com

I would like to have a protected, invisible link to a soundcloud block. We have a members area with large audio files. Would anyone have a suggestion to protect against people simply copying the url for the soundcloud link and using for free outside of the members area? Thanks!

Your site is private. Can you setup password & share url again? We can check easier