Interesting Observations About Using The D2 Audio Filter On An Actual Hunt

[Lodge Scent]

I decided to give the Audio Filter a try at one of my worn-out colonial era cellar hole sites. XP says that Audio Filter “cleans up the audio, sounds smoother, less instability, especially at depth.” I was using Sensitive Full Tones, Reactivity at 1 and Audio Filter at 5. My hope was that some iffy signals at the edge of detection would get cleaned up enough for me to decide to dig.

First diggable target was a fairly deep small cuff button. It was right in the middle of the cart path, and I know many coils have gone over it in the past. I should have set the Audio Filter back to 0 before I dug to see if it made a difference. But to be honest I thought it was going to be deep crusty bent nail. Next I dug 2 broken tombacs. Broken tombacs tend to give very poor audio responses, especially at depth. Next I dug a rather large button that was caked in rusty dirt. This surprised me also as I know many coils have been over that target in the past and somehow missed this large button. Then I dug another broken tombac. On this one I set the Audio filter back to 0 before I dug, and the signal definitely degraded to the point where I would not have dug it. I haven’t dug 6 nonferrous targets in one hunt from this site in years. 

Now obviously, setting the Audio Filter to 5 at an iron choked location will result in enormous amounts of falsing, but away from the heavy iron I think it has potential to help convince you to dig those questionable deep or weak nonferrous targets that you may have ignored in the past. In a real sense, the Audio Filter actually will get you some extra depth.

I’m definitely going to play some more the Audio Filter. The fact that I dug those 3 broken tombacs leads me to believe that the Audio Filter cleaned up those normally very iffy signals just enough for me to want to dig. I’ll be really happy if I can get it to clean up the signal at the edge of detection of a very early silver coin like a Pine Tree shilling. 😊

Lodge

[JCR]

Good on you. It really does pay dividends to experiment and learn the fine points of your machine.

[F350Platinum]

Hey Lodge, 

Gotta love those Tombacs! 👍 Oldest of the old. 

I have used audio filter at 5 for a very long time now for beach, I first discovered that it made some aluminum have a different sound. It's been beneficial. 

Looking at my relic program, I see it at 0, so I might put it at 5. 🤔 I don't run into much aluminum but it does sound like a good target.

[gopher]

I never really experiment with settings I don't really know what they do, suppose I'll never learn if I don't try

Audio filter, audio offset are two off the top of my head I've never changed

 

Got feet of snow right now, still be a couple months till I can detect, maybe March I can detect some snowbanks that melted back

[Lodge Scent]

6 hours ago, gopher said:

I never really experiment with settings I don't really know what they do, suppose I'll never learn if I don't try

Audio filter, audio offset are two off the top of my head I've never changed

 

Got feet of snow right now, still be a couple months till I can detect, maybe March I can detect some snowbanks that melted back

Gopher I admit to being in inveterate settings tweaker. It's just something I like to do....especially when over a target. Bummer about having "feet" of snow on the ground. Hopefully you get a decent thaw soon.

[Geologyhound]

Did you also find you were digging more old iron (square nails, etc.) at depth?

[Lodge Scent]

On 2/15/2025 at 8:49 AM, Geologyhound said:

Did you also find you were digging more old iron (square nails, etc.) at depth?

A bit more, but not a significant difference. A turn of the coil usually gave the iron away. I am willing to dig a bit more iron at these "worn out" sites. I am chasing very iffy signals to begin with. The Audio Filter will clean up the signal enough to get your attention, but they are still often iffy with using the audio filter. Just not as iffy. 

I used Audio Filter at 5 yesterday at probably my most worn out site. This is a very small (less than 1/4 acre) early colonial era home site. I managed to sniff out a few small deep buttons and a couple of broken tombacs. When I set the AF back to zero, I could see why these targets were ignored in the past. From what I have seen when using the Audio Filter, if I get a mid tone, no matter how crappy the signal is, it is a nonferrous object......usually a button, small lead or pewter bit. The high tones take more effort to sort out due to the iron falsing.