"and the resulting sound quality" is the only thing that works. Let's see if I can explain why! Most likely for parallelism - first you have 'pirating'. So you would need 'resulting' for the same structure. If you said, "pirated tapes resulted in poor sound quality", that would work (even though you had to change some words around).
And you are always a threat to someone/something, not a threat of someone. This is the active voice. You could say, "It carries the threat of ...", but that's more passive and different