A Question About GPZ Audio Response

[flakmagnet]

Okay, this may be a seriously dumb question but if you don't ask you won't learn.

This is a quote from the original MineLab release describing the audio response on the 7000:

"For example, the audio response for small gold will be a low-pitched tone followed by a high-pitched tone. A ferrous signal such as a bottle cap will produce a high-pitched tone followed by a low-pitched one, enabling the user to discriminate the ferrous target."

Have you GPZ owners found that smaller gold does indeed signal with "a low-pitched tone followed by a high-pitched tone?"

Thank you for any info. you can provide from direct experience. 

 

[afreakofnature]

Well.... no

i sometimes cherry pick hi-lows.

big nuggies come in sometimes as low-hi

trash is like a low-hi with sometimes a quick low.  Best place besides your own practice is to watch aussie gold hunters and listen.  You will see both and its fun to watch.  .  Or youtube channels can help too

[flakmagnet]

Yes on the GPX, larger and/or deeper nuggets would come in low-high. I am asking if what was stated in the MineLab statement about the GPZ, that small gold gives a low-high response, is what people are finding. I had never heard that before until I saw that description as I was looking at some older Minelab literature around the original GPZ release.

[jasong]

It does in Difficult sometimes on the fly spit bits. Not always, but sometimes. Not in Normal except very rarely from my experience.

General will sometimes invert the signal or go wobbly on bits that HY sound normal on but not nearly as much as Difficult will do it, in some specific parts of NNV I remember almost all the sub1/4 gram stuff was low high in Difficult when the GPZ first came out and I was trying to figure out if any settings would kill the salt response. Then in other areas it was a mixed bag.

On the other topic, sometime in 2015 I had a topic about how it seemed possible to do a sort of rudimentary discrimination by switching from Normal to Difficult or something along those lines, I forget exactly now because it was too time consuming for a guy with such a short attention span as myself haha, just easier to dig em all or mentally discim them out some other way. But it's possible to tell with some degree of certainty better than 50/50 what is iron and what is gold by the signals inverting or not in various settings and combinations. This was why I kept hoping for user customizable quick change setting buttons on a software update back then. The geometery and size change the response a lot though, but for your general bits of coin sized rusty tin can slaw it's possible. And nails need not even switch, you can usually tell just by drawing the shape with the tip of the coil. Coils of wire and boot tacks go all warbly so you can selectively not dig those too if the gold in the area is generally not warbly and there are hundreds of tacks everywhere and again you are a guy like me with a very short attention span. I thought for sure there would be a software discrim update by now based on these observations and my assumption they too had realized this quirk long before I did, and had future plans for exploiting it. Anyways, now I'm just rambling.

[Northeast]

I agree with JW - dig them all. 

I did find small lead shot was a consistent, rounded noise whereas tiny gold gave a similar noise but with a crackle to it.  Almost always knew when it was a less than 0.25 gram piece as it all sounded similar. 

But I also got gold that sounded exactly like lead shot.  

And 2 of my bigger pieces I was 100% that I was digging an old square nail.  

If you are trying to discriminate with a GPZ my feeling is you will be leaving gold behind.  JMHO  ?

[geof_junk]

The only consistent noise a tiny nugget makes,is the rattle in the keep jar.  

[klunker]

13 hours ago, flakmagnet said:

 

"For example, the audio response for small gold will be a low-pitched tone followed by a high-pitched tone. A ferrous signal such as a bottle cap will produce a high-pitched tone followed by a low-pitched one, enabling the user to discriminate the ferrous target."

 That was about as silly of a thing for Minelab to print as "Up to 40% deeper". As a general rule it my be correct but I have had some very nice gold make about every sound that the 7000 can produce , including the first line of Waltzing Matilda, and I have dug hundreds (Thousands?) of sure thing nuggets that were square and made of iron. I only try to discriminate with the GPX when I get lazy, which is most of the time, but I know better.

[flakmagnet]

Everyone's input matches and clarifies what I have always done with the GPX and the GPZ - dig (mostly), everything. I have found gold with almost every sound the detector makes as well (except for waltzing Matilda) but decided to ask my kind-of-stupid question to get clarification from the forum inhabitants. 

Thank you all.

[WesD]

Ya Flak,  the gpz audio seems to be all over the place, especially in Difficult ground setting. Gold seems to give almost a confused grunt signal.  In Normal, I tend to hear a high low signal on all small targets ferrous or not.  At least that's what my ears hear.  I wonder if that was a misprint in the Minelab article?

[jasong]

At this point in time I think we are decades in to understanding the "dig it all" mantra, and in my opinion there isnt much left to discuss since it's a simple concept that everyone already agrees on. So it kind of surprises me to see how many serious detectorists are content at leaving it there. The more interesting thing to me is when not to dig it all. If anyone thinks there is never a time to pass over targets then I guarantee you are missing more gold by being stuck in old ways than by realizing you can produce more by knowing there is a time to pass some targets up.

Consider some basic math, a philosophy which i used dredging and carried over to detecting. Let's say we accept 20% losses because I alter the sluice so it doesnt clog so much and I can run material faster over it (by removing the hungarians as an example) in return for doubling the material I run. In dredging that means I get 8 grams for running the same material instead of 10 grams. But I've doubled my material I run so I actually get 16 grams instead of 10 grams at the end of the day.

Same with detecting. Covering more ground is like running more material dredging. I accept say 20% loss of nuggets I miss in return for operating in a way that let's me cover 2x more land. That's actually an underestimate, I probably cover 3 to 10x as much land as a lot of the dig it all people I see detecting cover in a day. An average day detecting on my GPS is 2 to 7 miles walking, usually 4 miles a day is pretty normal.

If I am comfortable getting 80% of the gold in half or less if the time and then moving on and finding a new area, not only do I find more gold than if I stayed and dug every target in the end, but I end up with far more known producing areas discovered at the end of the season. And I go back to these areas at the end of the day if I've been skunked exploring and then THAT'S the time to grid and dig em all, and I end up with a lot of these areas in my back pocket to rely on whereas someone who stayed and just dug everything now has nothing left and no new discoveries either, starting from scratch every time. My way always keeps you in the gold and producing. Not just good for the pocketbook, but for the mental condition as well where going on skunk runs can be demotivating.

All that aside, having done this for years, I've discovered that even when I'm being highly selective I'm still only missing about 10% of the overall gold I end up finding when I do finally go back and clean up every single trash target. Yet I easily produce 2, 3 maybe even as much as 10x more gold per trip than I would if I simply stayed and dug everything until it was gone.

This is how you make detecting pay for itself if you aren't retired or depend at least some on the income you make finding gold. What isnt communicated properly when green horns read forums and threads like these is that a lot of the dig everything guys in the US who make fabulous finds are in fact just in tiny areas of private land or leased land which no one has access to, or claims which have been in the family for decades or longer, with heavy equipment at work. These people can afford to dig everything because they dont need to explore as much as the newer guys do. And a lot of other guys are shown places to go and dont have to put the work in to find them or go on 3 week long skunks and question why they ever bought a detector to begin with after digging 600 pieces of tin. 

Having recently spent a large amount of time cleaning out old "80%" areas I left behind for later, I've discovered that actually I got closer to 90 or 95% by selectively digging, and that's well within what I consider acceptable. 

A lot of age old mantras are repeated for a reason, because they are correct. But the trick is understanding when they aren't. For instance, there are perfectly good times you dont want to keep your coil perfectly flat even though coil control on the forums would make you think there is a school marm waiting at every patch to rap your knuckles if you dont.

Any different response you can get from a detector is potentially useful information. Data needs to be correlated and interpreted to your specific conditions, and tested and compared to see if it's a bad habit or potentially useful information. This is why I cant get behind this school of thought that seems to be getting common around forums that testing, measuring and comparing is not worth the time. This stuff has all been the key to my success as a person that started without anyone to help or show me where to go. And I know most random people starting out are finding themselves in the exact same boat as I was in, so if you are one of those new guys I'm letting you know that there are other ways to do this stuff, some of which are probably better for the conditions we find ourselves in today, and especially if you dont have a friend or buddy to put you on already productive ground.