I am using the x terra 505 well in fields with low minerals it s pretty good I found a lot of coins etc, I am using the 10.5dd coil wich it's awesome great with depth, but at the beach i had terrible time with the detector was at a competition with many other detectorists. it was too noisy and unable to noise cancel or ground balance except if sensitivity was too low and that was making it impossible to detect 2 or 3inches. Does anyone have any ideas about this I will appreciate if I could get help. Thanks in advance.