First, Miles is correct, "quiet" and crossbow are in opposite directions. Some are better than others, but they all are louder than you would hope.
Use the TenPoint Dampener, it will help some to stop the string, and slow the rebound viberations.
I wouldn't use the Bowjax, the bowstring on the crossbow tends to cut/squeeze the in-string silencers in two in a short amount of time. Your average x-bow poundage is 150-175, and the tension on the string is intense. Anything between the individual strings in the string bundle doesn't usually last long.
