GPZ 7000: Threshold Vs Sensitivity Vs Volume Vs Volume Limit (with Discussion On Audio Smoothing, Coil Control, Range Of Motion And Manual Ground Balance)

[flakmagnet]

I can speak to video production as well. I worked for 35 years on feature films and shot a number of documentaries on my own. That is I shot, edited, did the sound effects, wrote the narration and recorded it, did all the color correction, found and edited the music, and so on. I don't think it will come as a surprise that this is an incredibly time consuming pastime and requires a whole large learning curve of it's own - just ask JP who I am pretty sure had to learn all that to produce the amazingly high level of DVD's that he did. Each of his DVD's got better as his learning curve increased…and he had to compile the information as well. No casual undertaking.

Anyone who has seen the DVD's that JP has put out, or the docu-journals that Gold Hound has shot and edited, probably cannot imagine just how much time that took away from detecting, and for them, that means making a living. Both of them made what they did look as though it was easy. It's not.

I appreciate what afresakofnature is wanting to do and will only say that, as difficult as learning how to operate the 7000 is, just putting those concepts into a video and doing it clearly with proper examples, good production looks and quality sound and then putting it up for people to learn from, is not only a possibly huge project but it is also a huge responsibility.

All this is not to try to diminish in any way what is being discussed above, but rather, I am adding some details that I know about hoping to possibly help define, expand and round out the discussion.

A long P.S.: After reading so many discussions on these forums one sees that there is a wide range of approaches that people use when they are running their (in this case) GPZ’s. And while its true some methods may be more efficient and use the machines capabilities closer to its optimum, you really have to try hard to mess the 7000 up enough so it won’t go off on a nugget. My opinion only here, but personal preferences have to be learned by using the detector both in the the area where you are working and in the conditions that are present at the time.

[Norvic]

1 hour ago, flakmagnet said:

My opinion only here, but personal preferences have to be learned by using the detector both in the the area where you are working and in the conditions that are present at the time.

So very true for me this sentence, and I suspect for the majority of us. I add one more element and that is field experience over many years, once I considered I was close to having it down pat now I know I had blinkers on and will never get close, and to really put a spanner in the cog ML will come out with a new detector that blows all away, as they have for 30 plus years. Bring on the 8000?

[PhaseTech]

18 hours ago, afreakofnature said:

What are your thoughts on Volume and Volume Limit?  Do you a think I have their description correct?  Later today I am going to post up a visual to explain myself better.

P.S.  How is that requested "wireless" SP01 for the GPZ coming along? ?

First of all, the sP01 for the GPZ is already wireless, you just plug it into the WM12 ? 

Volume Limit is very simple, it's as others have stated already, just clips the loud part of the signal. The lower the Volume Limit setting, the earlier the clipping takes place. Faint signals are not affected until you start to get as low and 4 or 3, but it's been a while since I've gone that low. I would actually love if it functioned like a compressor/limiter as used in music production studios! 

Volume is a confusing one, as I have always believed it is just a carry over of the Target Volume control from the GPX's. Where as you turn it up, target signals (and any false signals being generated) are amplified. Threshold is also affected, but to a much lesser degree. Funnily enough though, the description in the GPZ manual seems to mirror the Volume Gain setting on the CTX3030. Straight from the GPZ manual: 

With a setting of 1, weak target signals will sound quiet, medium target signals will sound mid-range and strong target signals will sound loud. There will be greater differentiation between target signal strengths; however, weak signals will be harder to hear.
With a setting of 20, all target signals will be amplified to a loud audio response. At this setting there may be less differentiation between medium and strong signals, but weak target signals will be easier to hear.

Regardless of any of this, I find that Volume any lower than 8, and signals can easily be missed. Once you get it above 11, the machine becomes a little touchy, although other settings also come into play. My Volume is usually on 10, but can vary 9-11 depending on conditions. I find that is the sweet range. I am running headphones and sP01 95% of the time. 

 

[Gold Catcher]

What a good and productive discussion this has been. Thanks afreakofnature for having started this thread. There are clearly differences in opinions, but I note how much better our discussions have become, void of any personal attacks or nasty comments like we had back in the "X-coil days".  

[mn90403]

19 hours ago, Jonathan Porter said:

This then gets back to Range of Motion, a signal, depending on which direction you approach it, has a ‘lead in’ and a ‘tail out’. ‘Lead In’ is when your audio comes from a background ground signal behaviour that is averaged by the Semi-Auto GB just as the Threshold pitch starts to alter as the Rx of the coil starts to react to the field of a buried target, you then move the coil through the ‘Lead In’ section and pass over the loudest possible point of the target (dead centre or Ground Zero) this is where the target is at it loudest point assuming you have the coil over dead centre which is a whole different process of feeling around with the sweep direction and speed to find the true dead centre (Ground Zero).

JP,

Is this your definition of 'fringe' detecting? 

Hearing at first a faint target and then interrogating it to Ground Zero.  If your target is very deep/small then Ground Zero is proportionately small.  Some like me might think it an iffy target but an experienced detectorist would say it is a clear target in that situation.

Big targets are forgiving and can be heard with many settings unless they are too deep.  It is the little target sounds that require concentration and optimal settings for each of our styles.  Maybe these are the fringes the 6000 will excel at without doubting an array of other settings.

 

[jasong]

Only question I have left is are we going to have to just talk about the weather once the 6000 makes settings discussions redundant? 

[flakmagnet]

44 minutes ago, jasong said:

Only question I have left is are we going to have to just talk about the weather once the 6000 makes settings discussions redundant? 

I guess not if you have a 7000. Hope things are going good for you Jason.

[Jonathan Porter]

1 hour ago, jasong said:

Only question I have left is are we going to have to just talk about the weather once the 6000 makes settings discussions redundant? 

There’s enough user controls on the 6000 to keep us all busy, finding out whats going on under the hood and then using that to good effect is half the fun.

[Gold Catcher]

And then of course the speculation about the "8000" will also start soon. We will keep ourselves busy I have no doubt.