I'm just starting to get to know the XT-70. Is it true that with a digital detector like this, an audible threshold does not give better depth possibility, like it does on an analog machine? In other words, you won't get a slight rise in the threshold on targets too deep to get a good ID on? Is that why people are experimenting with the Prospecting Mode lately, to get more depth and a VCO controlled function to hunt with?
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Threshold on a Digital Machine like the XT-70?
- Thread starter Canewrap
- Start date
Like most detectors, the threshold setting is critical in maximizing the potential of the X-Terra. I think of the threshold as being an audible reference point, with the responsibility of letting you know if your detector's audio is set to the optimum level. If you set it too low, those small (or deep) targets might not "generate" enough of a signal to reach the point of being audible. On the other hand, if you set it too high, small (or deep) targets might not "generate" enough of a signal to overcome the sound being provided by the Threshold. A threshold tone is just what it says, a threshold. It is that precise tone, depending on your ability to hear a particular sound, that allows you to hear any change to that tone. If you are hunting in a Pattern mode, the threshold will blank out when you pass the coil over a rejected target. As well, the tone will increase when you pass the coil over an accepted target. My recommendation is to set your threshold at a point that it is just barely audible. Again, different folk's hearing may require different levels. And, your setting will also depend on whether or not you are using headphones, the quality of those headphones, or the "outside noise" at a particular site.
So to answer your question, I am convinced that a properly adjusted Threshold will make a difference in the "depth" that you can find targets. Due more to the ability to hear changes in that threshold as opposed to doing anything magic that increases the depth. I know when I found that silver 3-cent piece a couple months back, and my brother was unable to "confirm it" with his X-70 set with a "higher than required" threshold, we lowered his threshold down to a "barely audible tone" and he was able to hear it, no problem.
I do belive that under certain circumstances, more depth can be achieved with the Prospecting mode, than the Coin / Treasure mode. I attribute this to the fact that the Prospecting mode is a "true all metal mode" with iron mask capability. Whereas ALL of the Coin / Treasure modes incorporate a certain level of discrimination. And as we have learned over the years, most detectors sacrifice a certain amount of "depth potential" when discrimination is introduced. And usually, the more discrimination that is used, the more depth you sacrifice. I typically hunt in all metal, with mulltiple tones. I feel that using these settings, along with a proper ground balance, I am maximizing the potential of the C/T mode on my X-70. I also know that, the "All Metal Mode" is actually a zero discrimination mode, opposed to truly "all metal". Several of us have made posts along these lines, in the past. If you would like more information concerning these modes or setting the threshold, you can do a "search" on this forum and acquire quite a few posts. If you still have questions, let us know. JMHO HH Randy
So to answer your question, I am convinced that a properly adjusted Threshold will make a difference in the "depth" that you can find targets. Due more to the ability to hear changes in that threshold as opposed to doing anything magic that increases the depth. I know when I found that silver 3-cent piece a couple months back, and my brother was unable to "confirm it" with his X-70 set with a "higher than required" threshold, we lowered his threshold down to a "barely audible tone" and he was able to hear it, no problem.
I do belive that under certain circumstances, more depth can be achieved with the Prospecting mode, than the Coin / Treasure mode. I attribute this to the fact that the Prospecting mode is a "true all metal mode" with iron mask capability. Whereas ALL of the Coin / Treasure modes incorporate a certain level of discrimination. And as we have learned over the years, most detectors sacrifice a certain amount of "depth potential" when discrimination is introduced. And usually, the more discrimination that is used, the more depth you sacrifice. I typically hunt in all metal, with mulltiple tones. I feel that using these settings, along with a proper ground balance, I am maximizing the potential of the C/T mode on my X-70. I also know that, the "All Metal Mode" is actually a zero discrimination mode, opposed to truly "all metal". Several of us have made posts along these lines, in the past. If you would like more information concerning these modes or setting the threshold, you can do a "search" on this forum and acquire quite a few posts. If you still have questions, let us know. JMHO HH Randy
Randy, while I greatly appreciate your thoroughness, I was asking if there is a difference in the threshold between an Analog machine (like a Whites) and a digital detector (like the Xterra70). It would seem that with a digital machine, a signal that's just strong enough to break threshold should beep because digital is usually, either on or off. Although, in your explanation it does sound like the threshold does have a slight rise over deep targets, that doesn't necessarily give off a beep. You see, with the Whites I've been using for a while you can turn the threshold up, just past where its audible and listen for that slight rise that repeats. Maybe I'm splitting hairs here, but in my experience, its usually good for an extra inch or so in detecting depth. Hope that does a better job of explaining what I was asking. I know you must get basic type questions a lot, but I'm not looking for an explanation of threshold.
BarnacleBill
New member
Digital detectors are not like digital cellular telephones where low signal strength begins to create a BER(Bit Error Rate) that becomes so severe that the signal drops out. And by the way I hate digital cellular telephones for a wide variety of reasons. In a metal detector there are certain portions of the signal chain that are still analog, so they are really hybrids.
What the mixture of the analog versus digital portions of the signal chain are, is entirely up to the design engineers and they're not going to tell anybody. That's all very proprietary to each company, with each having their own marketing claims. So how much of the X-Terra processing is digital? Well that depends on how you characterize "digital". It could be 50% or 80%, because you have to take into account how much work is being done by software. It would take a great deal of reverse engineering by some very knowledgeable individuals to figure that out.
The X70 has a stepped threshold control that can be used to try to eek out more depth as Digger says, but it can also be used in the negative direction to lessen reaction to weak signals like small surface trash. So in that respect, being stepped you have repeatability and can turn it negative knowing exactly where it's set every time. Trying to turn an analog knob design negative and know where it's at is not an easy task.
It appears that in the Coin & Treasure mode, that the threshold is filtered, and this most likely is digital as it is very quiet and doesn't appear to rise much because the tones take over as soon as you hit a target. Now I have never run the X70 in a single tone with threshold on, as that just doesn't fit my style. Maybe in single tone there is a rise in the threshold, I've just never tried it. But that brings up an interesting issue. At the limit of depth of detection many ID detectors don't ID well at all, and therefore you're left with using the Threshold in All Metal mode to chase those deepies. The X-Terras tend to ID pretty well almost to the limit of their detection range. This of course is in average conditions where the ground matrix is not pulling the ID's on all detectors down into the iron range. Therefore depending on the Threshold is not as critical as in the olden days.
But in the Prospecting mode, it appears one is hearing very much more of the ground noise, and a much less stable signal than in C&T. So if you want to walk on the wild side and get every last inch of performance out of the X70, the Prospecting Mode will do it. That is if you have to have the patience, sometimes I do, and sometimes I don't. The X70 is a Chameleon, in about 5 seconds it can change from a very stable turn on and go coin shooter into a "If I dig one more piece of lead bird shot from 5 inches deep I'm going to scream!" detector.
You don't have to run the detector with a Threshold, it can be set to zero, which is where I have mine set most of the time, as I like it quiet. And I don't believe I'm missing much as far as weak targets, having experimented a little with & without Threshold audible. But those are my preferences, and the detector is easily adjusted to suit the end user and their moods.
HH
BarnacleBill
What the mixture of the analog versus digital portions of the signal chain are, is entirely up to the design engineers and they're not going to tell anybody. That's all very proprietary to each company, with each having their own marketing claims. So how much of the X-Terra processing is digital? Well that depends on how you characterize "digital". It could be 50% or 80%, because you have to take into account how much work is being done by software. It would take a great deal of reverse engineering by some very knowledgeable individuals to figure that out.
The X70 has a stepped threshold control that can be used to try to eek out more depth as Digger says, but it can also be used in the negative direction to lessen reaction to weak signals like small surface trash. So in that respect, being stepped you have repeatability and can turn it negative knowing exactly where it's set every time. Trying to turn an analog knob design negative and know where it's at is not an easy task.
It appears that in the Coin & Treasure mode, that the threshold is filtered, and this most likely is digital as it is very quiet and doesn't appear to rise much because the tones take over as soon as you hit a target. Now I have never run the X70 in a single tone with threshold on, as that just doesn't fit my style. Maybe in single tone there is a rise in the threshold, I've just never tried it. But that brings up an interesting issue. At the limit of depth of detection many ID detectors don't ID well at all, and therefore you're left with using the Threshold in All Metal mode to chase those deepies. The X-Terras tend to ID pretty well almost to the limit of their detection range. This of course is in average conditions where the ground matrix is not pulling the ID's on all detectors down into the iron range. Therefore depending on the Threshold is not as critical as in the olden days.
But in the Prospecting mode, it appears one is hearing very much more of the ground noise, and a much less stable signal than in C&T. So if you want to walk on the wild side and get every last inch of performance out of the X70, the Prospecting Mode will do it. That is if you have to have the patience, sometimes I do, and sometimes I don't. The X70 is a Chameleon, in about 5 seconds it can change from a very stable turn on and go coin shooter into a "If I dig one more piece of lead bird shot from 5 inches deep I'm going to scream!" detector.
You don't have to run the detector with a Threshold, it can be set to zero, which is where I have mine set most of the time, as I like it quiet. And I don't believe I'm missing much as far as weak targets, having experimented a little with & without Threshold audible. But those are my preferences, and the detector is easily adjusted to suit the end user and their moods.
HH
BarnacleBill
Mick in Dubbo
New member
Loved the comments about the bird shot Bill!
Mick Evans.
Mick Evans.
Maybe it's me but I don't really hear any difference on deep or small targets with the rise in the threshold. I mean it seems to me that the threshold and the beep tone are separate. Almost like the threshold drops out when you get a good target not so much as hearing a rise in the threshold. So I run the threshold on the 70 up to where I just hear it then back it down one notch. This is around #+2 for me. What say you?
I'm not talking about blanking from a disced out target. I'm talking about a rise in the threshold on tiny or deep targets. When you found your 9 inch dime you said it was a whisper. Did you hear a slight rise in your threshold or just a faint beep? I hear a faint beep. I don't hear a rise in the threshold. Could just be my hearing? But I have pretty good ears. Well at least they are pretty big!
Yeah, this is what I'm talking about. It seems that the threshold doesn't rise with deep targets and I thought I read somewhere that it doesn't react the same as an Analog machine does. I don't have any real deep, small targets buried in my test garden to find out if this is true or not. That's why I asked this question. Is there no one that's familiar with Analog machines, that knows what I'm talking about?
Sorry I misinterpreted your question......
In my opinion, the 230Hz Threshold tone of the X-70 is totally separate from the target tones, in the C/T mode. As khouse indicated, the Threshold tone seems to be replaced by the target tone, when a target is swept over. It is difficult to hear it fade out. But I am convinced I can hear a subtle abruptness in the 230Hz Threshold tone, as it returns.
In the C/T mode, the target audio tone (130Hz, 450Hz, 700Hz or 950Hz) is certainly a different pitch than the Thershold tone. There might be a specific target that would generate a tone in the multiple tone mode that was so close in frequency to the 230Hz of the Threshold tone that it might sound the same. But as one who hunts in all metal, multiple tone mode, I haven't heard one yet. But then again, if it sounds the same, would we hear it?
In the Prospecting mode, the Threshold tone remains, but changes in pitch and volume, dependent on the target.
The Whites detectors that I have currently have include the XLPro, XLT and MXT. On the single tone XLPro, the target tone seems to be an "extension" of the threshold tone. As I pass the coil over an accepted target, the threshold tone increases in volume. Same pitch as the Threshold tone. Just a difference in volume.
When I run the MXT in C/J mode, the single tone produced by the Threshold is the same pitch as the target tone. And just as with the XLPro, a target passing under the coil intensifies the "threshold tone" into a target tone. However, when I switch to the dual tone Relic mode, targets produce an audio response at a different frequency than the Threshold tone. Lower for targets below the rejection setting, and higher for accepted targets. And, it sounds to me as if the target tone and the threshold tone are both audible at that time. In other words, I don't think the threshold tone "goes away" on the MXT. In the CJ mode, the tone intensifies, indicating a target. In the Relic mode, the target tone "over-rides" the threshold tone.
When I run the XLT in the single tone mode, the results duplicate the single tone XLPro and the C/J mode of the MXT. However, when I switch the XLT to the multiple tone mode, targets react similarly to the Relic mode of the MXT in that both the Threshold tone and the target tone are audible simultaneously.
Based on these assessments, it would seem that running the Threshold tone at a "barely audible" level is more important on the White's single tone detectors than it might be on White's units capable of running multiple tones or the X-70.
This makes me wonder why Minelab instructs us to set the X-70 threshold to a "preferred" level. The reason they give is because small or deep targets might produce changes in the threshold tone that are so small, you won't notice a change in the sound. I understand that theory, if it were a single tone detector, the target tone was the same frequency as the threshold tone, and the threshold didn't fade out when a target tone is introduced. But in the case of the X-70, it seems to be none of the above. The target tones are a different frequency than the threshold tone. And, the threshold tone seems to "disappear" when a target is scanned. Like I said, it is tough to hear it fade out. But it sure sounds "sharp" when the target tone goes away.
I'll have to do some more checking on the tone "fade". And also as to why the manual was written with such explicit instructions on setting the Threshold. I'll keep you posted.
JMHO HH Randy
In my opinion, the 230Hz Threshold tone of the X-70 is totally separate from the target tones, in the C/T mode. As khouse indicated, the Threshold tone seems to be replaced by the target tone, when a target is swept over. It is difficult to hear it fade out. But I am convinced I can hear a subtle abruptness in the 230Hz Threshold tone, as it returns.
In the C/T mode, the target audio tone (130Hz, 450Hz, 700Hz or 950Hz) is certainly a different pitch than the Thershold tone. There might be a specific target that would generate a tone in the multiple tone mode that was so close in frequency to the 230Hz of the Threshold tone that it might sound the same. But as one who hunts in all metal, multiple tone mode, I haven't heard one yet. But then again, if it sounds the same, would we hear it?
In the Prospecting mode, the Threshold tone remains, but changes in pitch and volume, dependent on the target.
The Whites detectors that I have currently have include the XLPro, XLT and MXT. On the single tone XLPro, the target tone seems to be an "extension" of the threshold tone. As I pass the coil over an accepted target, the threshold tone increases in volume. Same pitch as the Threshold tone. Just a difference in volume.
When I run the MXT in C/J mode, the single tone produced by the Threshold is the same pitch as the target tone. And just as with the XLPro, a target passing under the coil intensifies the "threshold tone" into a target tone. However, when I switch to the dual tone Relic mode, targets produce an audio response at a different frequency than the Threshold tone. Lower for targets below the rejection setting, and higher for accepted targets. And, it sounds to me as if the target tone and the threshold tone are both audible at that time. In other words, I don't think the threshold tone "goes away" on the MXT. In the CJ mode, the tone intensifies, indicating a target. In the Relic mode, the target tone "over-rides" the threshold tone.
When I run the XLT in the single tone mode, the results duplicate the single tone XLPro and the C/J mode of the MXT. However, when I switch the XLT to the multiple tone mode, targets react similarly to the Relic mode of the MXT in that both the Threshold tone and the target tone are audible simultaneously.
Based on these assessments, it would seem that running the Threshold tone at a "barely audible" level is more important on the White's single tone detectors than it might be on White's units capable of running multiple tones or the X-70.
This makes me wonder why Minelab instructs us to set the X-70 threshold to a "preferred" level. The reason they give is because small or deep targets might produce changes in the threshold tone that are so small, you won't notice a change in the sound. I understand that theory, if it were a single tone detector, the target tone was the same frequency as the threshold tone, and the threshold didn't fade out when a target tone is introduced. But in the case of the X-70, it seems to be none of the above. The target tones are a different frequency than the threshold tone. And, the threshold tone seems to "disappear" when a target is scanned. Like I said, it is tough to hear it fade out. But it sure sounds "sharp" when the target tone goes away. I'll have to do some more checking on the tone "fade". And also as to why the manual was written with such explicit instructions on setting the Threshold. I'll keep you posted.
JMHO HH Randy
How far back in analog are you talking about? The old TR's I would think are about as analog as it gets.
I haven't used the MXT but have used the 6000 DI Pro, in my opinion, these or other current units are not affected to the extent as the older TR's by marginal changes in threshold. I am not saying a loss in depth is not possible with these newer ones but not as much as the older ones.
Threshold however is a very useful feature as it will alert the user to the presence of any metals present or changes in ground conditions.
HH
I haven't used the MXT but have used the 6000 DI Pro, in my opinion, these or other current units are not affected to the extent as the older TR's by marginal changes in threshold. I am not saying a loss in depth is not possible with these newer ones but not as much as the older ones.
Threshold however is a very useful feature as it will alert the user to the presence of any metals present or changes in ground conditions.
HH
That's why I run the threshold just at the level of silent search. I don't think the threshold itself rises at all on any target in the discriminating modes. In fact I think it goes away for an instant. I think it's just the animal. It's still the best machine I have used.