Marty,
I heard your bow as well last weekend. I thought it was extremely quiet.
I believe what you are hearing is arrow/string slap on YOU...its not noisy enough for others to hear...but YOU do.
Its more likely that, due to a different bow than you have shot before/ brace height difference, etc.
Why not try moving your stance to a slightly more open position and see if that fixes it...then you will know if I am right before changing things.
Don't worry about accuracy- just head them toward the bale and listen for whether sound is quieter.
A more open stance, a little more crook in your left arm should do the trick.