My thoughts on the Minelab Manticore

[AccurateCalls]

Purpose:
I just wanted to share my thoughts on the Minelab Manticore after 1 season of use, and how it fits into my detector lineup w/ XP Deus 2 and Equinox 800. If anybody has any questions, I'd be happy to answer them best I can.

Equipment:
Manticore, 11", latest update.

Results:
Manticore excels at EMI mitigation.
Slightly deeper means better odds at toning.
Soft keys are great.
Highly alertive / busy personality.

 

[Cherry Picker]

Purpose:
I just wanted to share my thoughts on the Minelab Manticore after 1 season of use, and how it fits into my detector lineup w/ XP Deus 2 and Equinox 800. If anybody has any questions, I'd be happy to answer them best I can.

Equipment:
Manticore, 11", latest update.

Results:
Manticore excels at EMI mitigation.
Slightly deeper means better odds at toning.
Soft keys are great.
Highly alertive / busy personality.

Thanks for the video.

While I agree with your perception that there is no best detector, the rest sounds like a commercial for the Minelab Manticore. I hear a lot of conflicting information, but then it is your opinion.

 

[sube]

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Purpose:
I just wanted to share my thoughts on the Minelab Manticore after 1 season of use, and how it fits into my detector lineup w/ XP Deus 2 and Equinox 800. If anybody has any questions, I'd be happy to answer them best I can.

Equipment:
Manticore, 11", latest update. Xp deus 2 9 inch coil

Results:
Manticore excels at EMI mitigation.
Xp deus 2 9 inch coil no problem or go somewhere else

Slightly deeper means better odds at toning.
xp deus 2 use a bigger coil use higher sensitivity

Soft keys are great.
Set your detector up before going or learn it well.

Highly alertive / busy personality.
Use a bigger coil or crank sensitivity up .

Weight XP deus 2 no contest fact

I could say the same about the Legend also but don't have one . Just learn the one you have they all have work arounds there all great compared to old detectors of the past . Top machines are still the ctx e-trac dfx v3i there all good .
But being a old codger the deus is still the lightest flagship detector FACT of course just my opinion . sube

 

[Diga]

Thank you for the video Loren.

I have some concerns on your methodology and conclusions:

Regarding EMI:

An induction balance metal detector doesn't know the difference between an EMI signal and a signal coming from the ground (be it the ground itself or a metal object). However, EMI typically produces signals that are weaker than the ground and targets, which is why reducing the gain, eliminates most EMI, while reducing depth. EMI also typically reads in the ferrous range, up to around the zinc range. That is why programs for cherry picking high conductors, gives the illusion of EMI mitigation.

What I'm getting at, is that in order for EMI noise reduction to work (and I use the term "work" very loosely), it must be accompanied by a detrimental effect in performance, in one way or another. For example, I can think of 2 ways in which an algorithm could reduce EMI, and they are both directly related to how we normally, and manually, reduce EMI:

1) The algorithm causes the detector to run in a pseudo SMF mode. More specifically, the algorithm causes the SMF to weigh much more heavily to a single frequency, thus reducing EMI noise. Although the detector would still technically be running in an SMF mode, some benefit of SMF would be lost. I suspect that the lost benefit would be a reduction in TID accuracy at depth.

2) The algorithm reduces a hidden, base level gain. This of course would reduce maximum depth, but would likely not be noticeable unless "before and after" comparisons were done on fringe targets. For example, in high EMI, find a target deep enough that Manti is just hitting hit. Then, do a long press noise cancel. IF, and only IF, the EMI is significantly reduced, then go over that target again. If the algorithm uses this method of noise reduction, then the Manti will no longer hit that target.

With all that said, there is no reason why the engineers from any other detector company can't create their own algorithm to use one or both of those methods. I suspect they don't because of the performance loss, but maybe they should anyway.

I was also going to include a critique of your depth conclusions, and more specifically, how 50% more power to the coil, results in little to no useable depth gain on coin sized objects. I was also going to address that unless I missed it, you didn't mention the 2D screen, and how it relates to nonferrous target identification. Which IMO, is less accurate than TID, because the TID gives a definitive number, whereas the 2D ID plotter is much more vague.
I'll put the depth and 2D screen critique in separate posts to keep things more tidy. I'll post them as I get more time to do so.

Being a fellow "science" guy, I'm certain you appreciate a different perspective on your conclusions

 

[Diga]

Regarding the Manticore's 50% more power to the coil:

According to a renowned metal detector engineer, a 50% increase in the magnetic field strength, results in a mere 7% increase in depth. And that would be under "perfect" conditions. As such, actual noticeable "in the wild" depth increases on coin sized objects would be marginal, especially considering that when the magnetic field's strength is increased, the ground signal is "lit up" at a rate much higher than a coin sized object. You simply get to the point that increasing the field strength, only results in drowning out the target, due to the exponential increase in the ground signal noise. That practical field strength "limit" was reached before the Manticore. Thing is, it is the ground itself, which limits depth on a detector, and not the brand of detector. Also, another negative effect of a 50% field strength increase, is a 50% loss in battery run time. That explains why the Manti has a much lower run time than competing detectors.

A better way to increase depth, would be to use a very low frequency, and a very low recovery speed, with gain adjusted accordingly of course. The Manti has a Deep HC mode that uses a very low frequency. The Legend also has that in its M3 SMF mode (most people don't know this), and so does the D2. Incidentally, Nokta is apparently going to release a "boost mode" update to the Legend. I find it very unlikely that it will be an increase in Tx output. I suspect that it will be an ultra low weighted SMF mode (even lower than its M3 SMF mode).

Above and beyond all that, simply stating that the Manti seems to go deeper than the D2, Legend, or whatever detector, is not evidence. A head to head comparison would have to be done on numerous targets, with hunters that know how to get the best depth out of each detector tested.

 

[itsaring!]

Interesting test you may try. Bury a stainless spoon bowl end only. Then run a test with both detectors on somewhat close to each other. Say 8'? Was testing out in the wild and the Deus ll couldn't hear a stainless spoon a Manticore could hear. Manticore appeared to hit it 4" deeper. We are going to take the exact same spoon dug to another area and see if you can replicate results. Just thought it would be interesting for someone else to try inland. Stainless can be tricky. And it's in the gold range. In other words maybe miss a large gold coin if you detect close to someone?

 

[Diga]

Regarding the Manti's 2D screen.

I submit that on nonferrous targets (which most of our hunting is for), that the 2D screen provides less accurate target identification than the TID and/or tones.

Let's take a dime in the ground for example:

The short wiggle over the coin should get, a specific number on the TID, or perhaps 2 adjacent numbers. On the 2D screen you would get a dot or an oval in the general vicinity of the high conductor range. The TID is more specific than the 2D screen.
I think the main benefit of the 2D screen, is the ability to show the iron content, regardless of the discrimination. That is an excellent aid to help identify true iron falsing. However, the Legend also does that with Ferrocheck, and the D2 does that with its X/Y screen.
In regard to the 2D screen being a benefit for selective iron digging, well, I find that to be quite a stretch. Reason being, if a hunter wants iron artifacts, then they typically dig all iron signals.

I don't know about the D2 when it comes to selective iron control, but on the Legend, the different levels of iron can be notched in or out for selective iron hunting. The Legend's bottle cap reject will also accept or reject certain iron based on the setting used. Ditto for its iron bias control, like any other detector that has an iron bias control.

 

[itsaring!]

Regarding the Manti's 2D screen.

I submit that on nonferrous targets (which most of our hunting is for), that the 2D screen provides less accurate target identification than the TID and/or tones.

Let's take a dime in the ground for example:

The short wiggle over the coin should get, a specific number on the TID, or perhaps 2 adjacent numbers. On the 2D screen you would get a dot or an oval in the general vicinity of the high conductor range. The TID is more specific than the 2D screen.
I think the main benefit of the 2D screen, is the ability to show the iron content, regardless of the discrimination. That is an excellent aid to help identify true iron falsing. However, the Legend also does that with Ferrocheck, and the D2 does that with its X/Y screen.
In regard to the 2D screen being a benefit for selective iron digging, well, I find that to be quite a stretch. Reason being, if a hunter wants iron artifacts, then they typically dig all iron signals.

I don't know about the D2 when it comes to selective iron control, but on the Legend, the different levels of iron can be notched in or out for selective iron hunting. The Legend's bottle cap reject will also accept or reject certain iron based on the setting used. Ditto for its iron bias control, like any other detector that has an iron bias control.

I've tried the Deus ll X/y screen and going by the 2D Manticore screen hunting salt beaches. I can tell you IMO your ears work way better than the X/Y or 2D screens ever could. Unless it is real shallow you get some weird art on the screens and would move on. I don't detect inland at all. So can't comment about anything there. I can tell you the beach hunters who said they liked the Deus ll X/Y screen on the beach in the beginning quit using it there.

 

[Diga]

I've tried the Deus ll X/y screen and going by the 2D Manticore screen hunting salt beaches. I can tell you IMO your ears work way better than the X/Y or 2D screens ever could. Unless it is real shallow you get some weird art on the screens and would move on. I don't detect inland at all. So can't comment about anything there. I can tell you the beach hunters who said they liked the Deus ll X/Y screen on the beach in the beginning quit using it there.

When I see live digs with the D2 or Manti, they either don't even use the X/Y screen, or hardly comment on the Manti's 2D screen when it comes to nonferrous targets. From what I've seen, the Manti users still go by tone and/or TID, and for the most part, ignore the 2D screen, unless they are trying to identify iron falsing. They'll often say, "Here's a good or bad tone, or here's a good or bad TID", but say nothing about the 2D screen. Probably because the 2D screen is giving them less accurate information than TID and/or tones

 

[Cherry Picker]

I've never had the pleasure to swing the Manticore, but the D2 gets compared a lot to it, and I did have the D2. Because of this, I have watched many videos comparing the two and I see more references to the D2 going a tad bit deeper than the Manticore. That is because they say the tones have more to say. We all know that beyond roughly 7" the XY and the 2D screens have little use. From that point it is tones.

In the end, most say there is little to no difference in depth performance in the top 4 detectors. That is also what I see on live videos.

 

[AccurateCalls]

An induction balance metal detector doesn't know the difference between an EMI signal and a signal coming from the ground (be it the ground itself or a metal object).

I get what you are saying here, but this isn't strictly true. EMI can have properties that can sometimes distinguish it from a ground signal. EMI can have a regular, periodic nature that a ground signal does not. E.g. a device like a powermain generating EMI at 50-60hz + harmonics. An Adaptive algorithm can 'zero in' on this periodic signal, approximate it, and then subtract it.

Idealized / oversimplified Example: We have a detector running at f1= 15 khz, and an EMI source at f2= 60 khz. The detector sees these two signals as the superposition of each corresponding sinewave, so f3 = sin(2*pi*15000)+sin(2*pi*60000). Since the detector knows it is generating f1, it can look at the received signal f3 and subtract f1 from it to determine f2. If the resulting f2 is perfectly accurate, then it will have had no reduction on performance, despite successfully canceling the noise.

However, as you noted, there will always be a performance loss because EMI is almost never a pure sine wave as in the idealized example. So these 'adaptive algorithms' are trying to approximate a function such that f3-f1 produces as little error as possible. Faster processors have definitely allowed for better adaptive algorithms that more rapidly respond to and reduce that error function to a minimum. These more responsive algorithms also tend to be more computationally expensive.

1) The algorithm causes the detector to run in a pseudo SMF mode. More specifically, the algorithm causes the SMF to weigh much more heavily to a single frequency, thus reducing EMI noise.

This is plausible, but I don't think we will ever know unless Minelab tells use. I still think most of the Manticores EMI mitigation comes from the inherent SNR boost from more transmit power.

2) The algorithm reduces a hidden, base level gain.

This I find entirely implausible. I couldn't imagine Minelab implementing such an unsophisticated and problematic approach to EMI reduction. Just imagine if this hidden value got stuck really low because EMI cancelation was last performed in a different, noisier environment.

According to a renowned metal detector engineer, a 50% increase in the magnetic field strength, results in a mere 7% increase in depth. And that would be under "perfect" conditions. As such, actual noticeable "in the wild" depth increases on coin sized objects would be marginal,

I find this statement to be in alignment with what I said in the video. The increased size of the magnetic field is marginal and the Manticore has a very modest increase in probability to produce a tone at the very edge of detection compared to a detector with a smaller magnetic field.

The 'limit of detection' isn't a hard line / sudden transition from a signal to nothing. There is a point at which the detector stops hitting the target on 100% of swings and then eventually deep enough that trends to 0% of swings. While both the D2 and Manticore will tone on these deep targets, the Manticore has slightly better odds from the increased transmit power. If you are walking over a deep target and maybe you only get 1 or 2 swings to produce a tone before you move on, the greater the odds of toning on that target, the more likely you will notice it to begin with.

Above and beyond all that, simply stating that the Manti seems to go deeper than the D2, Legend, or whatever detector, is not evidence.

I thought it was clear I was presenting my opinion on the detector and not evidence of anything. However, it's well supported by science that more power means a larger magnetic field that will have greater sensitivity at depth. How this plays out in reality is up for debate, but it is not up for debate that the Manticores magnetic field extends some amount deeper.

In other words maybe miss a large gold coin if you detect close to someone?

I found tons of weird behaviors among the Manticore and other detectors when they were in close proximity. I honestly couldn't make heads or tails of it and which detector was impacting the other more. This seems especially true when either one or both of the Manticore / Deus 2 is in Deep HC mode. Add in a few different brand pinpointers to the mix and all sorts of wacky stuff was happening. I have done some group metal detecting lessons and found it incredibly problematic.

I submit that on nonferrous targets (which most of our hunting is for), that the 2D screen provides less accurate target identification than the TID and/or tones.

Whether the 2D is less accurate or more isn't the point to me. The point to me is that the 2D screen contains different information that a single TID alone cannot contain. The 2D screen is basically a scatter plot of a whole histogram of TIDs w/ corresponding ferrous content. It contains information about how the TID varies over an entire sweep. A tight dot means little TID variance, and a larger smear means more TID variance. I personally find the more information the better, but it depends on your personal style.

 

[Rattlehead]

We set up the Manticore and D2 similarly (ATHC vs Deep HC), both with 11" coils and compared them on deep coins in the wild. My conclusion was the same as yours. Both detectors could hit the deep targets, but the Manticore seemed to have a slight edge in producing a more attention grabbing tone as the targets were swept.

 

[AccurateCalls]

When I see live digs with the D2 or Manti, they either don't even use the X/Y screen, or hardly comment on the Manti's 2D screen when it comes to nonferrous targets. From what I've seen, the Manti users still go by tone and/or TID, and for the most part, ignore the 2D screen, unless they are trying to identify iron falsing. They'll often say, "Here's a good or bad tone, or here's a good or bad TID", but say nothing about the 2D screen. Probably because the 2D screen is giving them less accurate information than TID and/or tones

I've tried the Deus ll X/y screen and going by the 2D Manticore screen hunting salt beaches. I can tell you IMO your ears work way better than the X/Y or 2D screens ever could. Unless it is real shallow you get some weird art on the screens and would move on. I don't detect inland at all. So can't comment about anything there. I can tell you the beach hunters who said they liked the Deus ll X/Y screen on the beach in the beginning quit using it there.

I was excited for the X/Y screen, but found it didn't bring any new information to the table that audio didn't provide and stopped using it.

I do find the 2D screen on the Manticore brings extra information to the table. For example, if we compare the tone produced by a TID of 70 that is exactly on the center line, compared to a tone produced by a TID of 70 that is just above the center line. The two tones produced by these objects are identical, but the 2D screen reveals one target might have a greater magnetic susceptibility since it is further from the center line.

 

[AccurateCalls]

We set up the Manticore and D2 similarly (ATHC vs Deep HC), both with 11" coils and compared them on deep coins in the wild. My conclusion was the same as yours. Both detectors could hit the deep targets, but the Manticore seemed to have a slight edge in producing a more attention grabbing tone as the targets were swept.

Yup, I think many people when they hear more depth, they think "Oh that means this detector hits something that the other cannot", when in reality there is no hard cutoff line at depth, but rather signals fade in magnitude until the magnitude of the ground signal overtakes them.

 

[Diga]

AC,

Thanks for replying to my points.

Regarding EMI:

If the EMI source was narrowband, then yes, EMI mitigation is easily accomplished. Problem is, with the various EMI sources, frequencies, harmonics, etc, EMI is rarely narrowband; for all intents and purposed, EMI is random. If it were narrowband, then any EMI noise reduction, on any detector would work wonders. It wouldn't have to be a Manticore to do that noise reduction .

Yes, the possibility of a pseudo "SMF mode" for the Manti to accomplish its noise reduction, is the most likely possibility. The other possibility I gave about the sensitivity drop, is another possibility, albeit I agree that it's unlikely.

Regarding the 2D screen:

I see it as a different way to identify targets, but not necessarily "better". Like the example I gave, the 2D screen provides less information than TID and/or tones. Can you give a specific example in which the 2D screen changes your dig / no dig decision, in a way that TID and/or tones could not?

 

[Diga]

We set up the Manticore and D2 similarly (ATHC vs Deep HC), both with 11" coils and compared them on deep coins in the wild. My conclusion was the same as yours. Both detectors could hit the deep targets, but the Manticore seemed to have a slight edge in producing a more attention grabbing tone as the targets were swept.

Whenever I see such comparisons, I also see words like "seemed" and "slight". Enough so, that the actual difference is probably well within the margin of error, or a simple change in the frequency, recovery speed, etc.

 

[AccurateCalls]

Problem is, with the various EMI sources, frequencies, harmonics, etc, EMI is rarely narrowband; for all intents and purposed, EMI is random.

If you read one paragraph further, I actually agree with you.

EMI is almost never a pure sine wave as in the idealized example.

Nonetheless these techniques can still be applied, with some error (this causes the reduction in performance you mention). That is why I say the goal is to minimize this error function.

Can you give a specific example in which the 2D screen changes your dig / no dig decision, in a way that TID and/or tones could not?

Yes, see the example I described in the reply above and for a more specific example, Here in Finland we have these things called 'klippes' which are square coins cut from sheets of metal. They tend to produce a 2D screen plotting that is slightly off the center line (without knowing more about how FE/FE2 iron bias works, it's hard to say why these coins do this). This coinlike signal that appears just below the centerline is a tell-tale sign of one of these highly desirable klippes. This difference / information is not encoded in audio anywhere.

It seems FE2 (how far below the centerline line) says something above how 'plate-like' / 'sheet-like' the object is and this seems to align with the square sheet like nature of 'klippes'.

 

[Rattlehead]

Whenever I see such comparisons, I also see words like "seemed" and "slight". Enough so, that the actual difference is probably well within the margin of error, or a simple change in the frequency, recovery speed, etc.

There isn't always a simple black and white answer. Sometimes we speak on what we *think* is happening based on results, hence the words seemed and slight. No, it doesn't make it a fact, but when multiple people are seeing similar results, that info is worth consideration.

 

[Diga]

Yes, see the example I described in the reply above and for a more specific example, Here in Finland we have these things called 'klippes' which are square coins cut from sheets of metal. They tend to produce a 2D screen plotting that is slightly off the center line (without knowing more about how FE/FE2 iron bias works, it's hard to say why these coins do this). This coinlike signal that appears just below the centerline is a tell-tale sign of one of these highly desirable klippes. This difference / information is not encoded in audio anywhere.

It seems FE2 (how far below the centerline line) says something above how 'plate-like' / 'sheet-like' the object is and this seems to align with the square sheet like nature of 'klippes'.

Like any other target, do those klippes produce a different trace or ID depending on their depth and orientation? Also, since the 2D screen is plotting the TID(s) of the klippes, then can you do the same klippes identification with the TIDs? Aside from that, that is a very unusual and obscure example, that most would never encounter.

In regard to your last paragraph, are you suggesting that an ID plotter is somehow showing the shape of the target?

 

[AccurateCalls]

Also, since the 2D screen is plotting the TID(s) of the klippes, then can you do the same klippes identification with the TIDs?

TID alone contains less information than TID + displacement from center line. This displacement from the center line can only be heard when it crosses the ferrous limits and therefore produces a ferrous tone.

In regard to your last paragraph, are you suggesting that an ID plotter is somehow showing the shape of the target?

No, the 2D screen is a histogram of TIDs plotted against their FE/FE2 iron bias values. Its a visual indication of how these values change over a sweep. However, shape does impact how the object interacts with the magnetic field to some extent over a sweep, some of this can be indicated in this 2D screen, but actual shape cannot be inferred.