Silent search Vs Threshold tone?

[TN Mike]

I started this thread in "Eriks Audio", and nobody seemed interested in the discussion. Thought I'd give it a try hear.


Just wondering what you all think about the two in comparison. Was thinking about buying a new detector and was wondering if a little light could be shed on which is the best. I currently have MXT and am just starting to focus on the "whispers". Upon trying to discern the "whispers" I noticed times when the threshold would null out rather than rise as some people suggest it would do. Thought I was doing something wrong, but my guess is, is that the hum will null if the detector is set to discriminate the sort of metal in the ground. And would make a slight audio tone if it cant recognize the object (discriminate it). Seems to me having a threshold is all around better for ground balance as well as finding deeper targets. You can hear the ground breaking up your hum VS having to stare at a screens read out.

Just wondering if I'm understanding the concept of threshold correctly? Seems to me that its the only way to.

 

[ExpIInut]

Just what do you call a whisper? How do you set up your threshold tone? How high do you run your gain? - just curious.

 

[TN Mike]

From what I understand, the "whispers" are very deep targets just out of the mxt's range of identification. The detector when when set to the maximum achievable depth (as high a sensitivity as you can run without excessive chatter), and just a barely audible threshold, very deep targets will cause the threshold to null or slightly rise depending on your discrimination settings. Then you switch to all metal mode and center the target under the coil to try and get the detector to ID the target (from my understanding you should also turn your disc all the way down while doing this).

Settings = High sens (as high as you can get it, +3 if you can), slightly audible (with head phones) threshold. Center target in all metal/pinpoint, and turn disc off and try and id the target.

Just seems like a threshold used in this way gives me more confidence in the detector. I dunno maybe silent search detectors are better due to the silence (picking out faint signals)?

I'm still sorta new to doing this, so for those who understand this better, I'd love to hear your input. I'm hoping to build a small headphone amp to see if it will help me out any.

 

[Dustyroundup]

Howdy,
I recently started doing the bench tests, from the EDGE book , that cover this topic." to hear the effets of Mixed Mode audio firsthand"

When the target signal is too weak to provide a VDI number, the mxt is still providing an indication of its prescence.
And , the way I take it, if it cant provide a VDI#, then it doesnt really know if its ferrous or non ferrous, and will respond as such.
sort of all- metal i guess.
and I think it depends on which mode you are in , on how it responds, i.e. a break in the threshold or a raise in threshold
This is all new to me, and I'm going to have to do quite a bit of these tests to get it down.
But hey! its winter in Montana,, what else is there to do?

Good Luck ,
Dusty

 

[RounderRick]

From what I've learned like Dusty said if it's to deep for the detector to give a vdi then it don't know if its ferrous or non ferrous the rise in the threshold just indicates it's a deep target and it's up to you to investigate it.
If the threshold nulls that means the target is within vdi range but that target is below your disc setting but you should still see a vdi for that target because the disc on the mxt don't affect the vdi indicator just the tones.
The mxt edge book is a great investment for ones learning the mxt it make learning so much faster because it covers pretty much anything you need to know about the mxt including the whispers with tips and tons of information.

 

[BarberBill]

A just audible threshold sound is desirable to that you can hear a slight rise in tone when over a deep and/or small target. On the MXT the threshold will definitely null out when the coil is over metal that is being discriminated out. On my settings that would usually be iron when I'm coin shooting. Some don't care for a threshold hum, but I prefer it as long as it's set very low, in the background.
BB

 

[JohninNC]

I agree with BarberBill on the threshold hum. I hunt with a slightly audible threshold hum. If there is no hum then it is possible that the threshold is set either slightly below the threshold hum cutoff or a bit more than slightly below the threshold hum cutoff in which case a whisper or small increase in the threshold may not reach the point of making it audible. For that reason alone you should always hunt with a slightly audible threshold hum. You definitely want to hear everything you can. The only exception is a relatively new tot lot. Nothing will be very deep so you can hunt in silent mode with confidence you are not missing anything good. HH John

 

[ExpIInut]

From what I understand, the "whispers" are very deep targets just out of the mxt's range of identification. The detector when when set to the maximum achievable depth (as high a sensitivity as you can run without excessive chatter), and just a barely audible threshold, very deep targets will cause the threshold to null or slightly rise depending on your discrimination settings. Then you switch to all metal mode and center the target under the coil to try and get the detector to ID the target (from my understanding you should also turn your disc all the way down while doing this).

Settings = High sens (as high as you can get it, +3 if you can), slightly audible (with head phones) threshold. Center target in all metal/pinpoint, and turn disc off and try and id the target.

Just seems like a threshold used in this way gives me more confidence in the detector. I dunno maybe silent search detectors are better due to the silence (picking out faint signals)?

I'm still sorta new to doing this, so for those who understand this better, I'd love to hear your input. I'm hoping to build a small headphone amp to see if it will help me out any.

Right! now I'm with you - I hunt in all metal with the threshold tone set to just audible with the trigger switch in the Centre position - I then flick it forward to search - I am doing some very old pasture and every now and then I get a signal that shows nothing on the screen and is not like an ordinary audible signal but what's called the Mixed tone - it is quite distinguishable and once heard is never forgotten - on more than one occasion I have had to remove 8 to 10 inches of soil to get a positive signal - in fact this ground has thrown up a few of these signals that I've given up on due to time constraints (I'd rather dig 15 small holes than 1 large one) - I've just invested in a Garrett Pro Pointer and as it happens am going back to this field tomorrow - as regards my settings - 10 x 12 SEF coil - Relic mode - auto ground - ZERO discrim - gain flat out and ignore the chatter - a mixed tone will stand out believe me.

 

[TN Mike]

So I guess my question is, what do you guys think about silent search vs the ability to listen to the threshold. I guess I don't know enough about detectors to know the difference between the two technically. For example, with a mxt you can hear a small but audible gain in the threshold, as a result you know something is there. But, with silent search style detectors how do you know the the detector isn't holding the signal back so to speak. Or lacking in depth in this regard.

This is something I guess I'm having trouble with

Thanks you all for your input.

 

[ExpIInut]

There is no simple answer - but to put your mind at rest I hunt with an MXT and like to hear everything - my partner uses a Laser / Tesoro Rapier and always in silent mode - at the end of the day on most sites our finds rate are the same.

 

[Larry (IL)]

You understand fine Mike, that is the advantage of having a slight audible threshold as apposed to silent search. A deep/small target might slightly rise the threshold, (if audible) but the signal might not be strong enough to break through the silent search threshold to give you a "beep". The differences are small and there really is not a significant difference in the two modes IMHO, but a slight audible threshold is preferred by advanced hunters.

 

[TN Mike]

You understand fine Mike, that is the advantage of having a slight audible threshold as apposed to silent search. A deep/small target might slightly rise the threshold, (if audible) but the signal might not be strong enough to break through the silent search threshold to give you a "beep". The differences are small and there really is not a significant difference in the two modes IMHO, but a slight audible threshold is preferred by advanced hunters.

Thanks for your answer.

 

[Jeff-TN]

Threshold!!!!!! I have found alot of nice, deep, relics and coins just by the rise of the threshold,

Jeff

 

[TN Mike]

Ya there's just something about a threshold that makes me feel more confident about what the detector is seeing. I guess its one of those things where the more you feel you are getting back from the detector the more confident you feel..if that makes sense. The silence I think would just make me go off in dream land lol.

 

[srf2112]

Ya there's just something about a threshold that makes me feel more confident about what the detector is seeing. I guess its one of those things where the more you feel you are getting back from the detector the more confident you feel..if that makes sense. The silence I think would just make me go off in dream land lol.

I think you hit it on the head TN Mike. As Larry and others have stated, once you learn how to effectively use the threshold to locate the deepest targets it WILL give you that little bit of added depth overall as opposed to a silent search machine but I think the real advantage it gives you is confidence as you said. This craft is unique in that it is just as much mental as mechanical and having piece of mind and confidence in your equipment is everything. When you are constantly reassured that you're machine is working properly ( and on ! ) you can relax, get in a rythm and focus on the little details and that's how great finds are made. Without that you'll not only be lost and missing targets but you'll lose all the enjoyment. This is what the threshold does for me so I'm a firm believer in it...JMHO