Safari and threshold

ClodChopper · Apr 2, 2014

I put in several hours with my new Safari. It's pretty easy to use, my learning curve is progressing nicely. One question about threshold. On my other units, higher threshold usually ment better depth. I've been manually setting my threshold, in the 14-18 range...with headphones. I used it once without, and still never went above 18. Perhaps I'm wrong, but I don't see any noticeable difference in depth. Am I correct in presuming, greater depth is not necessarily (as) dependent on higher threshold? Actually, the few times I turned threshold 20+, it seemed small targets were more difficult to hear.

Longhair · Apr 2, 2014

If you want to miss more, turn the threshold up. When it comes to threshold and depth on targets, less means more.
Threshold should be clearly yet minimally audible. First understand that target size, shape, mass, and proximity to the coil are all important factors. A silver Canadian 5¢ (fish scale) @ 4" might easily be interpreted by your machine as a silver dime @ 7" or a silver quarter @ 12".
Threshold works similarly to squelch on a radio receiver. The higher it's set, the stronger of a signal is required to "break" through it. So if your threshold is set higher, that fish scale @ 6" might not produce a return signal strong enough, nor would the dime @ 10" or the quarter @ 14".
Another analogy might be something like this. If you're in your living room with the TV on, and your wife is in the kitchen talking to you, you might have a hard time hearing her (not always a bad thing :laughing7:

). But if you turn the TV volume down, or if she came closer, you might easily hear her. The TV volume is like the threshold tone competing with your wife's voice the same as a distant or small target return signal competes with the threshold volume.
Make sense?

Treasure_Hunter · Apr 2, 2014

Correct you should be able to hear threshold, but should not be loud at all, I make mine like a small irritating mosquito near my ear.

loud will mask out the deep, faint targets..

American by birth, Patriot by choice.

I would rather die standing on my two feet defending our Constitution than live a lifetime on my knees......

sask hunter · Apr 2, 2014

Great explanations guys

D.A.D.D.-Dads against daughters dating

ClodChopper · Apr 2, 2014

Makes perfect sense. Actually, understanding it in the terms you expressed, puts the reasoning for some of the factory presets into better prospective. I was using the target volume setting like a master volume. If I understand you correctly, I should turn the target volume up, and set the threshold to the lowest, but audible setting. I should be able to hear smaller targets deeper.

Longhair · Apr 2, 2014

Correct!

ClodChopper · Apr 2, 2014

Well, with this new prospective, I see a purchase on the horizon. The RPG headphones that came with the unit are comfortable, but allow a lot of external noise through. Looks like it's time for a better set.

Treasure_Hunter · Apr 2, 2014

ClodChopper said:
Well, with this new prospective, I see a purchase on the horizon. The RPG headphones that came with the unit are comfortable, but allow a lot of external noise through. Looks like it's time for a better set.

Kinda like owning a $2500 sound system and pair of $100 speakers. You hear the music but your still missing a lot.

American by birth, Patriot by choice.

I would rather die standing on my two feet defending our Constitution than live a lifetime on my knees......

ClodChopper · Apr 2, 2014

I'm looking at the Grey Ghost, they seem nice. Killer B makes some stuff that seems comparable for a few dollars less. Both have similar features, both are 150ohms. We'll see...

Longhair · Apr 2, 2014

Look at Sun Ray Pro Gold phones too. They are usually available for about the same price ($125-135).

Jeremy76 · Apr 2, 2014

Good info here. I appreciate the explanation as well.

Treasure_Hunter · Apr 2, 2014

I use the new Grey Ghost Amphibians they are really good and comfortable too..

American by birth, Patriot by choice.

I would rather die standing on my two feet defending our Constitution than live a lifetime on my knees......

ClodChopper · Apr 3, 2014

It looks like the Grey Ghost and Sun Rays, have a shape that may fit me better. I'm 6'4, my head is freakishly large and I wear glasses. The taller ear cup on those brands, will probably fit me better. Was looking to stay in $100-$120 range, but Grey Ghost makes a set with a replaceable cord, for a bit more. I like that feature.

ghosthunter55 · Apr 3, 2014

You can't go wrong with the Grey Ghosts.....

Coldshuz · Apr 3, 2014

Does the AT Pro have some special/unique headphone jack? I googled and looked at about 5 links for the Grey Ghost Amphibians headphones and all seemed to say they were for the Garret AT Pro.