I'm no expert but:
1) If you hit a 6 iron 190 or so, you are longer than the average PGA tour pro. Who cares what the sound is...you should worry about your miss.
2) If the miss is a block or hook, both are usually as a result of coming too far inside out, and these TEND to be very shallow strikes on the ball, so the thudding should be minimal.
Unless you totally stall and/or flip it while early extending. Which might be the case if the grip in the picture is what you use. that's a very weak left hand grip. So you may come aggressively over the top, wide open face, unconsciously stall, jump and chuck the hands/club face at the ball. And when you time it just so, its a beauty.
Recommendation - see an instructor for a session, get a little video, get some data off a Trackman or Flightscope, go from there.