There are no standards in test gardens......
Jmoller, even if "test gardens" could be erected, as you say (or better yet, flagged un-disturbed naturally occuring signals in the ground, that a multitude of machines are tested on, and then the target is dug to see what-it-is), are still bound to be obscured, arbitrary, biased, etc...
I have, even myself, tried to compare signals in this way. Either for my own use (my own self trying each subsequent machine over a flagged signal), or to show it to buddies with other machines, for them to sample.
The problem then becomes, is that it's FAR TOO EASY for the next person to simply say "yeah I hear it" and "yeah I'd dig it", and so forth. Why? Because they've just been pointed out an exact spot, so OF COURSE they're going to be craning their ears, criss-crossing multiple ways, etc.... When you *already know* something's there, then you're going to be subconscsiously already interpretting any flutter as being a "yeah I hear it".
For example: One time I was hunting in a jet-black-mineralized cesspool of a gully wash where rain water/culverts had eroded a path to the beach, on a So. CA beach. It crossed right under one of the historic piers. And as I saw this erosion, I could see lots of nails exposed (reddish rusty little lines all scattered through the gully-wash-channel). I hopped down into the mess, and found that my humble Whites Eagle could barely get 2" deep in the jet black salt minerals! But no problem, as least I could knock out those nails with ease, so I proceeded to pick out coins (even some older silver) from the mess.
Along the beach comes a guy swinging a Garrett. He sees me digging targets in the channel, and asks if he can join me. I see that he's swinging a particular Garrett that I knew, for a fact, was very poor in minerals. So I told him that , yes, he could join in, but that .... be prepared for some nasty black sand. I sorta wanted to see how his machine would compare. At that exact moment, I was getting a conductive signal. So I tell him: "here's one now as a matter of fact, let me know if you can hear it". He jumps down in, turns on his machine, and swings over the spot I'd just shown him. And he got it LOUD AND CLEAR. With "room-to-spare" as a matter of fact. I could even hear it coming in over his headphones. So he turns to me and says "yes I hear it". Boy was I impressed. But I was also suspicious. So I say, "how about over here?". And as he starts to swing his coil elsewhere, the problem became immediately evident: He was getting signals EVERYWHERE d/t the black sand, and had assumed that the "signal" he was getting where I'd pointed, was .... a differentiable signal. He didn't last more than 5 min. in that mess, and left for greener grounds.
Oh, and by the way, a pulse guy came along too, and saw me in my little honey hole. I invited him in too, knowing that since he had a pulse, that the minerals would give him no problems. But I warned him: there's lots of nails in here". To which he says: "no problem, I can tell them by their sounds!" Well .... 15 nails later ... he too left for greener grounds. Doh!
Another time, I was given a CZ6 to test at a particular park where I knew deep silver lay. I started with my Whites, and was able to flag a particular signal that .... in my experience of this park, was probably going to be a deep wheatie or silver. Then I took the CZ6, and waved it over the same spot, with a variety of different settings, swing speeds, directions, etc... I was ABSOLUTELY AMAZED that the CZ6 not only got the target with ease, but also got it with room-to-spare, correct ID, etc.... I was very impressed. Dug it up, and it was, as expected, a deeep silver or wheatie. So then I proceed to swing the CZ6 elswhere around that spot, and get immediate hits, that sound and read exactly the same as the signal I just dug. But upon digging those, they were various other things like deep nails that were fooling the TID, or teensy eraser tops or odd-ball things.
Now I know, with the CZ6 illistration I just gave, that no doubt, CZ6 fans would come on saying that there are tricks to knowing those deep nail falses. Or tricks to knowing shallow vs deep clad/oldies. And they would justifiably "take issue" with the observations that I made. I'm fully aware of that. Or they'd argue that I wasn't experienced enough, and so forth. I'm fully aware of that, and the truths that do come with experience of nebulous nuances of each machine. BUT THAT'S JUST THE POINT! The point being, is that it becomes HIGHLY speculative, arbitrary, individual, etc... NOT things which can be simply measured on a 1 to 10 scale, and so forth.
