Deus 2 which is faster recovery, 5 Tones vs FULL TONES

[Cherry Picker]

Let me clarify my original post. I was not making any statement that FULL TONES had a slower recovery speed than 5 TONES, but a question as to if it could possible. Somehow we got off on processor speed and such, but I was just curious as I've seen many Youtube videos where not only the author, but you can hear that using less filtering resulted in a faster, and crisper tone. Not just their pinion, but I could hear it as well.

I was just trying to explain why I feel it could be a possibility. My time spent working with processors and audio processing has me wondering.

 

[Diga]

You can think of recovery speed as being comparable to shutter speed on a camera (not a perfect analogy but close). The longer the shutter is open the more light is gathered, but things also get more blurry.

Also detectors take advantage of the fact ground signals change slowly over time where as a coin for example creates a more sudden change. So you can amplify or reduce a signal based on how quickly the signal is changing. Recovery speed also likely changes the rate of acceleration / amplification of signals. Which is why lower recovery speed produces a longer tone than a higher recovery speeda shorter tone on the same target. E.g. you can amplify based on the derivative of a signals change with respect to time.

That's how I understand it as well. However, I can see such changes as having maybe a 1" depth differential, but min to max recovery speed results in several inches of depth difference. It kind of seems like when the recovery speed is reduced, the transmit power is reduced and/or the sensitivity is reduced.

 

[AccurateCalls]

That's how I understand it as well. However, I can see such changes as having maybe a 1" depth differential, but min to max recovery speed results in several inches of depth difference. It kind of seems like when the recovery speed is reduced, the transmit power is reduced and/or the sensitivity is reduced.

The transmit power definitely doesn't change. On detectors sensitivity refers to amplification, but there are different types and ways of amplifying a signal. Sensitivity can be thought of as broad amplification across the whole signal. Whereas recovery speed is acceleration / derivative dependent amplification.

That's also why increasing recovery speed reduces ground noise in mineralized soils and improves effective depth, those ground signals change slowly / have a smaller derivative than a coinlike signal and thus fall below the acceleration dependent amplification threshold.

That is what the terminology 'reactivity' refers to. Amplification that reacts to sudden changes in signal.

 

[Diga]

I understand what you're saying AC.

In general, the recovery speed changes the sample rate interval. It's easy to understand how that results in significant separation performance. However, I'm still finding it difficult to understand how the sample rate interval has such a large degree of depth difference.

I guess I'll just have to try understanding a little "deeper"


BTW- When changing the recovery speed, is it just the sample interval that changes, or does the sample saturation time change as well?

 

[AccurateCalls]

I understand what you're saying AC.

In general, the recovery speed changes the sample rate interval. It's easy to understand how that results in significant separation performance. However, I'm still finding it difficult to understand how the sample rate interval has such a large degree of depth difference.

I guess I'll just have to try understanding a little "deeper"


BTW- When changing the recovery speed, is it just the sample interval that changes, or does the sample saturation time change as well?

Changing recovery speed likely changes several settings 'under the hood' and they are all tied together under one option called recovery speed to make it user friendly. At the end of they day we can only speculate as to how Minelab/XP proprietary software works exactly.


Taking a weak signal from a deep target and amplifying it based on the rate of change of the magnitude of the signal, combined with additively more data points allows for deeper detection (also more noise and false signals and emi etc).

 

[Cherry Picker]

Why do I get the feeling I'm conversing with a pseudonym LOL.

I'm just wanting to know if there is any difference in recovery speed between using FULL TONES & 5 TONES on the D2. if there is no difference then the answer would be no. If you don't know, just say so.

 

[Beachhunt1]

if there is any difference in recovery speed between using FULL TONES & 5 TONES on the D2.

What type of no would you like?

 

[Cherry Picker]

What type of no would you like?

No, would have been sufficient. A simple no, not some teched-up explanation that is subject to personal opinion. I can do that.


In general, producing a single tone in a metal detector audio circuit is faster than producing a multi-frequency tone.

Metal detectors typically operate by emitting an electromagnetic field and then detecting changes in that field caused by nearby metallic objects. When a metallic object is detected, the metal detector circuit generates an audio tone to indicate the presence of metal.

For a single-tone output, the circuit can generate a steady frequency signal corresponding to the desired tone using a simple oscillator circuit. The generation of a single-frequency tone involves bfewer computations and signal manipulations, allowing for a faster response time.

On the other hand, generating a multi-frequency tone in a metal detector audio circuit requires more complex signal processing. This typically involves generating multiple simultaneous frequencies or using frequency modulation techniques to produce a tone with a varying frequency spectrum. The additional signal processing steps required to generate multiple frequencies can introduce some delay in the audio generation process, resulting in a slower response time compared to a single-tone output.

The reason I ask.

So, yes or no, or I don't know is acceptable. LOL.

 

[AccurateCalls]

No, would have been sufficient. A simple no, not some teched-up explanation that is subject to personal opinion. I can do that.


In general, producing a single tone in a metal detector audio circuit is faster than producing a multi-frequency tone.

Metal detectors typically operate by emitting an electromagnetic field and then detecting changes in that field caused by nearby metallic objects. When a metallic object is detected, the metal detector circuit generates an audio tone to indicate the presence of metal.

For a single-tone output, the circuit can generate a steady frequency signal corresponding to the desired tone using a simple oscillator circuit. The generation of a single-frequency tone involves bfewer computations and signal manipulations, allowing for a faster response time.

On the other hand, generating a multi-frequency tone in a metal detector audio circuit requires more complex signal processing. This typically involves generating multiple simultaneous frequencies or using frequency modulation techniques to produce a tone with a varying frequency spectrum. The additional signal processing steps required to generate multiple frequencies can introduce some delay in the audio generation process, resulting in a slower response time compared to a single-tone output.

The reason I ask.

So, yes or no, or I don't know is acceptable. LOL.

No is definitely the answer.

There is no meaningful difference in terms of processing latency to output full tones or 5 tones.

I'd actually argue a detectors raw signal is closer to a full tone scheme (albeit real life phase shift changes are subtle so the tonal range must be expanded to be easier to hear tone differences for a human ear) and that 5-tone scheme actually requires additional processing on the raw signal to output (clamping / tone fitting). But again, it has no affect on performance.

Its specious reasoning to suggest that more tones require more processing since a raw, unprocessed signal is literally full tones. But again, without knowing specifically how it was coded we can only speculate on which process is computationally more expensive. A programmer's design decisions could make either outcome possible.

 

[Cherry Picker]

Its specious reasoning to suggest that more tones require more processing since a raw, unprocessed signal is literally full tones. But again, without knowing specifically how it was coded we can only speculate on which process is computationally more expensive. A programmer's design decisions could make either outcome possible.

Suspicious? By default, a tone generator produces a single tone and not a full spectrum tone.

I guess some testing would be my best option.

 

[AccurateCalls]

Suspicious? By default, a tone generator produces a single tone and not a full spectrum tone.

I guess some testing would be my best option.

Specious not suspicious.

 

[jmaclen]

I am not an audio or software engineer.

I am an older guy that has been detecting for a long time.

The first VLF detector that shocked me with its recovery speed and unmasking was Deus 1. I had to change my thinking about VLF detectors after owning one. It simply did not completely behave the way that other VLFs did that came before it.

When the Equinox 600 and 800 were released, I had to change my thinking again and I also had to really transform my detecting skills as far as how currently produced simultaneous multi frequency detectors behave. They do not operate like the earlier produced simultaneous multi frequency detectors made in the late 1990s and the early 2000s.

Number of tones being used versus one, number of frequencies being used like single frequency gets more "power" than dividing the power between multiple simultaneous frequencies, discrimination circuits........these no longer matter nearly as much as they did in the past when filtering had to be considered based on processing capabilities.

So, from experience, I have not noticed a discernible difference in target separation and unmasking between Deus ll 5 tones and full tones. The same goes for the Equinox models and the Nokta Legend. Some testing like TNSS suggested might make the answer more definitive.

I am not even sure if the actual frequency/frequency weighting, low versus higher has all that much effect on target separation and unmasking anymore.

I am more concerned about wireless audio lag than I am about how well these newer intermediate and professional level simultaneous multi frequency VLF detectors can separate and unmask targets.

 

[Cherry Picker]

Specious not suspicious.

Sorry AC, my eyes just ain't what they used to be.

I did get out and do some testing just a bit ago. My results were not worth recording. You are correct that both FULL TONES & 5 TONES didn't seem to make any difference on recovery speed, with the exception that FULL TONES had the tendency to do more clipping of the tone than 5 TONES. Of course, this would be expected as FULL TONES carries more frequencies so a slow swing speed did make a difference in FULL TONES clipping at the start and end of the tone. Both tones, I felt had the same good response as far as alerting the user to a potential target.

So, my question is answered. Personally, I liked the 5 TONES while randomly swinging, but the FULL TONES had more information once I isolated the target. Both seemed to have the same VDI. The targets I tested were at a minimum of 10" in the wild at my natural test bed park. That said, I still have got to give props to that 20 year old FBS. It didn't leave much for even the newest tech.

 

[AccurateCalls]

Sorry AC, my eyes just ain't what they used to be.

I did get out and do some testing just a bit ago. My results were not worth recording. You are correct that both FULL TONES & 5 TONES didn't seem to make any difference on recovery speed, with the exception that FULL TONES had the tendency to do more clipping of the tone than 5 TONES. Of course, this would be expected as FULL TONES carries more frequencies so a slow swing speed did make a difference in FULL TONES clipping at the start and end of the tone. Both tones, I felt had the same good response as far as alerting the user to a potential target.

So, my question is answered. Personally, I liked the 5 TONES while randomly swinging, but the FULL TONES had more information once I isolated the target. Both seemed to have the same VDI. The targets I tested were at a minimum of 10" in the wild at my natural test bed park. That said, I still have got to give props to that 20 year old FBS. It didn't leave much for even the newest tech.

Haha no problem at all. My dyslexic brain swaps words around all the time, actually had to check I didn't type suspicious.

I think in terms of tones it just comes down to preference / how much info you want to deal with.

 

[Cherry Picker]

Haha no problem at all. My dyslexic brain swaps words around all the time, actually had to check I didn't type suspicious.

I think in terms of tones it just comes down to preference / how much info you want to deal with.

Agreed 100%. I could be happy with either tone. As I said, I found the 5 TONES a little more pleasing during my normal swinging, but FULL TONES was more revealing once I had a target to investigate. The iron grunts for one were more distinguishable for example.

Still working on a game plan for those pesky hairpins. They often tone as a high conductor and read a VDI in the 70s to 90s. Of course, a quick turn usually reveals the iron grunt and low 06-08 VDI, but still, a few can fool the D2 right up to using the pinpointer.