Audio Notch

[XP-Man]

this is a question regarding audio notch not gound notch.

Trying to get some XP answers.. does audio notch effect depth? or just hides the sound?

 

[squirrel1]

Try this experiment with air testing a dime. Be sure when air testing to keep pushing out the distance until no audible tone exist using dime.

Turn your deus on go to basic one. Sweep clad dime for air test distance. Measure. Note distance. Then notch out from 0 thru 2 points less than what clad dime reads when swept. Then repeat air test distance and measure, note distance.

I notice loss of fringe depth tone when notching close or to the wall I call it.

 

[CZconnoisseur]

I've noticed nickels are notorious for not falling into "nickel range" depending on some soil conditions. Just a few days ago I got a jumpy nickel-ish indication that bounced from mid50s to lower 70s while in 12 khz. Dad checked it with his AT Pro (surprisingly the AT Pro has very close VDI readings to the Deus for most coins while in 12khz!). Turned out to be a 6" deep nickel that was heavily corroded.

Many, many nickels behave like this, and a quick jump to a 12khz "open" program (hardly any notch) will help the audio signal immensely! Every now and then I get an audio signal WITHOUT VDI, and many times these are coins (again, mostly nickels here) that are co-located with trash.

Have had other hunts where the aluminum is insane...in these places I will usually drop to 4khz and notch 00-65 which allows most copper and almost all silver coins. In my opinion though, YES...depth is impacted with liberal amounts of notch and since the Deus doesn't always give dead-on VDIs then any notching CLOSE to the expected VDI value does indeed affect depth.

To answer the second question - IN most cases a notched value will also not have any sound, but occasionally you'll get a blip or chirp or something very close to the "notch edge". Dig these targets! Every time!

 

[squirrel1]

Great post CZ.

 

[Ism]

Notch is not precise, it has a +/- 8 points of error, if I remember right. If you set it too close to the ID range you wan't to hear, it may notch out those very signals.
Good example is the observation Squirrel gave. However, it shouldn't affect depth if given proper consideration.