Red clay pockets and ironstone are predominant throughout the golden triangle - unfortunately its a fact of life. Wal and Nugget are 100% spot-on. Its the reason manufacturers send their detectors and coils to the Triangle for testing - if they work here, they can work anywhere. (As an aside, a lot of prospectors don't have to change settings all day long in WA like you do in Vic). I do not know enough about the Garretts to comment on a solution, but the Minelab SD and GPX (2000 - 5000) all suffer the same. DD coils tend to be a quieter option which I have heard the ATX is doing OK with. Usually its a matter of re-balancing close to but not on the ground noise then re-detecting. Then if the sound continues, dig a round hole bigger than the coil and re-detect over the hole, not in it. If it is louder the continue, if it has come out - check, if it moves or is still broad, strong chances are you are on 'hot ground'. You can usually see hot rocks pretty quickly and the same goes for pockets of that red clay. There is, as always, a catch with clays - because it is usually hard, large nuggets have been found on the clay layer - a clay bedrock if you will. Even now, I to get interested in these ground noises as they do sound nice but 99% of the time, I can discount them pretty quickly. The bonus is, you are 100% detecting on ground with quartz that has been subject to mineralisation which are indicators that it could be gold bearing ground. Some parts of Creswick are quieter than most due to the amount of quartz wash not far below the surface so Creswick should be a kinder place to detect.
