I have had my Garrett pinpointer for a couple months now, and I love it.The other day I taped over the Speaker with electrician tape to make it a little more resistant to water. I go by vibration anyhow, as with my hearing being bad, I do not always hear the high pitched tone. Here is the deal. As soon as I taped over the hole, I suddenly got about 25% better depth. It's like I put a booster on it. ......What gives?????