Could someone explain threshold: AT Max

[Gannon]

Okay so Ive read the manual several times, and I know adjust it to conditions, EMI etc. But my main question is am I loosing anything by keeping it on 00 or no threshold?

I don't like to really hear a HMMMMMM in my headphones constantly so I keep it on zero mainly.

So are there advantages to to using a neg Thresh? if so when?

Thanks!

 

[John-Edmonton]

ADJUSTABLE THRESHOLD
Allows the user to manually adjust the audio threshold
(constant background sound) to better hear targets.

So, searching for tiny nuggets or real deep targets, the user must hear very faint signals. So, you add some threshold, and you can hear the soft signals, you could miss just counting on hearing a random signal. You can also use the threshold feature in reverse, where the detector is very unstable. You start adding negative numbers to calm it down.

The threshold feature only works in true all metal mode on either the AT MAX or AT Gold.

 

[vlad]

If you run a lot of gain, somethings can cause it to be erratic; mineral or electromagnetic interference for example. If the threshold is erratic instead of stable, the sensitivity is too high. Back off on until the threshold is stable. Or you can really crank it and run the threshold negative to the point you cannot hear the erratic noise. Its a tradeoff, you can experiment with (disc mode.) Running it silent in the
stat mode can cause you to miss the fact that the unit is less sensitive due to drift, or the ground changing (and needing a new ground balance.)

 

[JimmyCT]

It seems to me the Max is much more sensitive to ground minerals. " machine is sparky" Going negative for me calms the machine down and quiets the erratic behavior. To me I don't believe I am loosing anything but the erratic behavior. I feel I hear the good targets even better with a negative threshold between -3 and 00. The only thing I wouldn't do is go any deeper than -3. Of course I need to experiment even more with this. However I performed a test on a 7" silver quarter and noticed as I reached -7 -8 -9 on the negative threshold, the audio response to the coin started changing. (see below)

For me, when I am in a lot of iron I generally do not go deeper than -3 in threshold. In cleaner ground, I'll keep it AT or NEAR 00. Hope this helps - Jim




I then returned to the 8 bars of sensitivity and then adjusted the threshold.
As I scanned back and forth over the silver quarter I kept on reducing the threshold until I reached the max of -9.
This is what I learned: from -1 to -6 in threshold, no indication of audible change.
However when I reached -7 -8 – 9 I can hear the audio changing. Basically, the more negative the number the audio softens and is not as clear and sharp like -1 through -6.


http://www.findmall.com/read.php?79,2396800,2396800#msg-2396800

Okay so Ive read the manual several times, and I know adjust it to conditions, EMI etc. But my main question is am I loosing anything by keeping it on 00 or no threshold?

I don't like to really hear a HMMMMMM in my headphones constantly so I keep it on zero mainly.

So are there advantages to to using a neg Thresh? if so when?

Thanks!

 

[MikeLab]

If you are hearing snap, crackle, and pop, you might not hear a good target in the middle of all that, so by turning the threshold lower you want to find the point where the good targets come through all the garbage so they are easier to hear. This can mean going down into the negative numbers. If you go too low you won't hear the good targets, so try to find the sweet spot. I've seen this mostly in wet sand. You don't have to be on the beach to experience this--many grass areas have a sand base or sand mixed in the soil so wet lawn can give somewhat the same effect as wet sand. John is right, the threshold is mainly for All Metal mode because the DISC modes filter out a lot of the crud.

 

[Southwind]

I miss the good old days of the normal threshold. Today it seems to have a threshold you must be in AM (all metal) which I hate. Far too much trash in my sites to run in AM but I love to hear that ever so slight hum of the threshold. Ever the smallest change, positive or minus, could be heard.