Nexus Sensitivity Settings 'Less Is More'

I believe sensitivity is one of those subjects in metal detecting that can be misunderstood easily, people tend to see it in a black & white way, more sensitivity = more depth & less sensitivity = less depth. In some aspects this could be the case but in others, not so much. I like to look at the elements involved, the way I see it is, the higher the sensitivity the more potential for ground interference. When this happens that interference or 'noise' could actually contribute to the deeper targets being missed because there's a chance you won't be alerted to them. It's irrelevant on digital machines, I don't look upon these as deep seeking units, but for Nexus the 'noise' could effect those 'really deep' signals. I'm talking about coin sized objects in excess of 14' - 17' inches. Now don't misunderstand me here, you'll be surprised just how hard both the V2 & V3 hit on these types of signals, especially with the 13' DD coil, I'm just explaining the process to help bolster my point about sensitivity. 

It needs to be understood that targets at that depth are not going to be blowing your ears out, they have a tendency to gently phase in with a fluid rise in the threshold followed by a sweeping audio. If you do hit on a target at those kinds of depths, once you isolate it and continue to swing over it you'll find on most occasions the signal gets stronger. I've noticed this a lot in the past when using all my Nexus machines including the Credo DDM it's like the machine locks on harder the more you swing over it.

To stand the best chance of hearing these targets we need to limit the ground interference as much as possible, obviously ground balance contributes towards this. One of the best analogies I can give you is on the subject of Tinnitus, having started drum playing so young I had chronic Tinnitus come on when I was about 16. Just to explain what this is, it's a constant ringing in the ear or ears, it's the worst at night when things are really quiet. One trick that I use to do to help elevate the annoyance 'when we had analog TV's, was turn on the television to a channel that had white noise on it and leave it on this channel at a low volume, this would help mask the ringing and help me fall asleep.

Did this magically make my tinnitus disappear? no it didn't, the ringing was still there I just couldn't hear it because of the audible noise. So if you then move this example over into the sensitivity discussion it's obvious that excess noise could act as the 'white noise' that obscures the deep targets. On both the MP V2 and the Credo DDM they go deep with zero sensitivity, running the machines this way allows you to hear everything, it also enables you to help judge the depth of the targets you dig because nothing is being manipulated due to added sensitivity. In general both the ground and detecting experience is a lot quieter and controlled.

So When Do We Use Sensitivity?

When I first got my MP V2 there was that instant, want to crank the sensitivity up as far as it could go - I was going to get super deep stuff doing this .. right?. Wrong, it was utter chaos, the machine literally turned nuclear, using the 13' DD coil I was hitting on microscopic bits of non ferrous items which quickly became a complete pain in the butt. I learnt very quickly that higher sensitivity might hit hard on deep stuff but it's going to hit bloody hard on everything, big, small, shallow and deep. After getting burnt early on I decided to use both my Credo and V2 on zero sensitivity for at least the first 3 - 4 months. Doing this gave me ample time to really understand both machines, after this period I decided to nudge the sensitivity up a notch or two BUT... only when I was using my smaller coils, I found the smaller the coil the more you could dial the machine in with a higher sensitivity setting. 

Because I'd gotten use to the machines operation and what all types of signals sounded like, the problems that occurred previous when using a higher sensitivity weren't a problem because I knew what to listen for. I understood the differences between the signals and how the machines responded, it soon became apparent with the sensitivity nudged up a fraction, the signals seemed to hit a lot harder, also it was a little trickier to gauge the depth. I was hitting on coins at 10' inches plus and the audio sounded like they were just a few inches down, following on from this, I understood that there were certain situations and environments where I could get away with cranking the sensitivity up with no problem. This was on sites that were pretty benign of mineralisation and land where targets were more spread out, on sites with a lot of iron contamination the machines had a tendency to run better at the sensitivity on zero. On these types of sites we are going for unmasking and separation, depth isn't a priority. Lastly wet ground wasn't conducive with a high sensitivity setting.

Why Isn't There An Adjustable Sensitivity Setting On The MP V3?

The MP V3 has a fixed sensitivity to make it more user friendly and it's one less element on the machine to cause confusion. Because many out there looked upon the sensitivity dial on Nexus machines in the same way as the sensitivity setting on the digital machines, people were misusing it. It works completely different, making the detector a lot more sensitive to the ground as opposed to making smaller or deeper targets just sound louder. The baseline sensitivity setting on the V3 is more than enough to match and exceed the depth capabilities of the V2. It's working on the basis that less is more meaning that you will hear the super deep stuff because the potential 'noise' that an adjustable sensitivity dial can produce when misused has been removed from the equation. 

When people initially saw that the V3 didn't have adjustable sensitivity there was discussion about the potential loss of depth, I'd like to make it clear that no depth has been sacrificed, if anything it has enhanced it. Remember the more stable the machine runs the smoother the threshold thus enabling you to hear everything, but let's remember here, if there aren't any deep targets to be had then you aren't going to find them - common sense .. right? wrong, people still ask me why I'm not digging 50 cm coins and relics .. the mind truly boggles. no machine out there will magic up targets in the ground that just aren't there. One things for sure though, if there are deep signals then I know I'm going to hit on them.

In regards to all the above and park hunters in the states, in these environments zero sensitivity would be the best option because you're not exactly going to be hitting on super deep 50cm targets in the parks. Using both the 10' DD and 11.5' SS coils, you're still going to punch beyond any other machine out there with the same coil size with the V2 at zero sensitivity or running the V3. What I've written about in this blog is directed to the guys out there hunting ancient sites where targets could be found at extreme depths.