I don't pay that much attention to swing speed. I never have an issue with swinging to fast for it, but I am not in a race when trying to hit these faint short beeps. Yesterday me and my buddy hit the park we have been going over again with our Nox 800's. I only found one deep wheat. It had to be about the length of my Garrett pin-pointer deep with iron in the hole.
It was not my best signal of the day but turned out to be a coin. My best signal of the day turned out to be a bent nail really deep. I probably dug half a dozen really iffy signals and like I said got one wheat for the effort. Yesterday I had no scenarios where I was super confident I had a coin after I got a faint high tone chirp.
We need to define what we are talking about here concerning masked coins. There can be a big difference on how masked a coin actually is.
One is where another detector might not detect it and the Nox does giving a good tone and numbers that can be instantly identified as a coin pretty quick. These are the ones where you don't know if the item was just missed by another detectorist or if his detector just could not detect it. This is not the type of scenario we are experiencing at this park.
Next is the tougher one where the Nox just gives the short chirp, but when circled you are given decent numbers all the way around the target that give you high confidence it's a coin. This is the scenario we have run into most at this park when deep silver or Wheats were found. This is the type where all other detectors except the Nox failed to detect the coin.
Lastly there is the scenario that is masked the worst. You still get a very short high chirp, but it might change to an iron grunt as you circle and the VID will jump around wildly with a target masked this bad. This may be just faslsing iron. These are the ones where you will be digging more bad targets than good, but I have been pleasantly surprised with a silver and a couple of Wheats.
i believe the "second scenario" you described is where the difference will be really noticeable! the first scenario you can pretty much forget about in a park that's been 'cooked" for years! for the MOST part, those coins have been found! the second scenario is the one that gives "hope" that the efforts expended will produce coins again,and to be perfectly honest,it's what will keep the "anticipation" factor high. this is the "edge" guys are looking for! it's either this way to hunt,or take up Knitting!"..ehe! he! he! that "short high squeak" followed by "warbling" over that "exact" spot will get it done!
(h.h.!)
j.t.