and to be honest, after 35 years of digging coins, the X-Terra is the first detector that I have worked in the all metal mode. I attribute my "change of habit" to the various tones associated with specific notches. I am not a big fan of hunting modern parks etc. Just too much aluminum can slaw around here for my patience level. I prefer to spend winter months researching where people congregated 100 - 150 years ago. And digging old coins in the Spring and fall. Homesteads, picnic grounds, chautauquas and racetracks. Today, most of those areas are simply farm ground. The buildings are gone, as are the grandstands. But when those buildings were torn down or burned, the nails were left behind. I use the all metal mode to help me determine just where those specific sites were. I research old newspapers and plat maps. I make copies of those maps on the computer and overlay them onto a modern map. That process enables me to find the current owner of the land and gain permission to hunt. Once at the site, I may find 160 acres of corn stubble. Now 160 acres may not sound like a lot of turf to cover. But to put that 160 acres into perspective, it is an area the size of 120 football fields. Lots of ground when you don't know precisely what you are looking for or where to start. At the site, I am constantly looking at the ground for pieces of broken glass and pottery. And, by running in all metal, I can hear those areas where nails are now buried. If I were in a discrimination Pattern mode, I may not even know when I walked over the area where the grandstands once stood. All-Metal provides those tips.
When I hunt in all metal, I use the 4 tone option on the X-50 and X-70. Although the X-70 offers a multi-tone mode (I believe 28 tones), it is too much information for my ears. I prefer to just listen to 4 tones and basically let the low tones go un-noticed. Well, I do notice them, when they become concentrated in one area. And, I may dig a few to see if they are nails or pieces of abandoned farm equipment. If they are nails, I know I am close to a place where people were congregated. As I pass the coil over the ground, I stop and dig the high tones and medium high tones. I also dig the medium low tones, if the target passes my "consistency" test. (Location, Tone and TID) I believe that I am better able to separate good targets that are adjacent to ferrous targets when I listen to both low and high tones. If I am in a Pattern mode and rejecting ferrous targets, I may not hear that subtle break between the iron and the coin. (due to blanking by the rejected target) But with all tones available to me, I can sweep the area from multiple directions, trying to separate the two tones into two distinct targets. I know that there are not many on here who have found the 3 kHz coil to be their choice. But again, I believe that I can decipher the low tones (produced when using the 3 kHz coil) from the higher tones better with the 3 kHz than any other coil. Something about the sharpness of the low tone "breaking off" when the high tone begins. This is a sound that is very difficult to explain. But I know that it works for me, in the sites I hunt.
Hope this explains my use of the all metal mode. If you have any other questions, I will try to answer them. HH Randy
HH Randy
I even put a note on the rod that said "turn off the probe dummy!", 
but I'd even forget to read the note. 
My grandkids say I suffer from CRS. (can't remember $tuff) Wait a minute. Was that my grandkids? Heck, I can't remember now who it was that told me that! 