Proper Use Of Notch & Discrimination Settings

[Critterhunter]

I find it curious that very little talk in relation to these two aspects of the Sovereign is ever discussed. I think it's odd that some people (including me) put so much stock into what the Minelab techs have to say about proper use of the machine when it comes to things like sensitivity or volume settings, yet many people have the attitude that discrimination but more in particular the notch is somehow a giant blunder that those same techs should have never bothered with. If we are to take and believe their expertise and knowledge when it comes to certain other aspects of this machine, I don't think people should have the attitude that they knew so much with those things but totally drew a blank when they added the discrimination and notch. Those aren't two "extras" they threw on the machine just to make the face plate more symmetrical, they are there for a reason.

Sure, most of us prefer to hunt with no discrimination or notch, in particular when old coin hunting, as this lessons the chance that you might not notice a masked coin that at first only sounds off in relation to the pull tab or other junk it has sitting near it. If you were to notch or discriminate out certain unwanted items then you might never hear them in the first place and have the chance to sweep around them to see if there is a coin signal hidden in there. Even a coin at depth or tilted a certain way can by first glance (sweep) sound of somewhere much further down the scale, where it would never be heard should the discriminate or notch be set to reject items in that range.

Most of my detector experience over the last 10 years has been on the QXT Pro. Oh sure, I've gone back and fourth to other machines but I always ended up back to that unit. It was deeper than any of the other various machines I've used on silver and copper, and I really enjoyed the ability to assign high tones to any of the 8 specific zones it had for targets. While that didn't sound like much in the way of resolution, you'd be surprised at how VDI and audio reaction could help you split hairs on various targets, including the difference in everything from zinc pennies copper ones, to clads, and then silver.

Mainly, my preferred method of hunting was to not edit out any of those 8 zones, including the ground signal (hot rocks) or iron. I would instead assign high tones to the particular targets I was interested in. More often than not this was the nickle zone, the zinc penny zone, and then the coin zone that it crammed all the other coins into. Interestingly enough, the "nickle" zone, like that on many other machines out there, could be anything from foil to pull tabs, and as a result I dug way less in the way of nickles because I often avoided that zone. With the GT I've dug more nickles than with any other machine, including my Explorers. It's VDI resolution and telling audio on stuff in that range is excellent. When it says 142 to 146 or so and locks on to one number with good audio you can start digging your nickle.

Mostly with the QXT Pro I trained my ears to do my discrimination. Two tones could only be assigned, a low tone or a high. I would listen for that high pitch tone amongst trash or at depth and found myself a boat load of silver in doing it. That's just an example of why it's never a good idea when old coin hunting to use any form of discrimination. Of course on the beach it's also a good rule never to use any. It's pretty much scoop every target because of the ease of using a sand scoop and also the potential for the next "pull tab" to be a gold ring.

However, I don't care how die hard we all are at digging it all. There comes those places and points in time on land when there is either just way too much trash, or we are simply too tired to do anything but try to cherry pick. Mostly with old coin hunting I don't care how trashy it is, I'm using my ears. But, just the same, there are places where the trash is so severe that using no form of discrimination is more of a hindrance than a help. You simply can't concentrate due to all the never ending random signals that are blasting away at you. Your concentration suffers and you start getting "bumped around" in your head by the onslaught of never ending multiple signals occurring with each and every sweep. That's when it's either do something about it or go crazy trying, and that's why Minelab put notch and discrimination on these machines.

So I thought this would be an interesting topic to kick around. I'm sure I'll hear from the die hards who say even touching either one of those dials is a sin. Fine, good for you, but as good as my tolerance is for "hearing it all", even I can't take it anymore at sites that look like they hosted Woodstock. So let's dive into the pros and cons, who thinks what, and why they do it. I'll start off...

 

[goodmore]

I usually hunt the sand and just dig everything. But there are times I find myself detecting in the dirt. I make sure the toggle is in discrimination. Good-Bye iron. I'm not a Relic man. I don't want to deal with iron at all.
Since the beginning of my detecting days (Young boy) I have only ever dealt with two kinds of trash that I really felt I needed help with. Foil & Pull tabs.
Discrimination knob kills the foil.
Notch kills the pull tabs.
Oh I have been in bottle cap spots. I just dig em. Can slaw? That can be almost any VDI. Usually all over the place. No way to really reject it.

So to me Discrimination means iron and foil and notch means pull tabs. I use them when I have to.

 

[Critterhunter]

The first strategy is the easiest to understand. At locations that are just the worst of the worst some seasoned Sovereign users use what they call "Silver Mode". That's when discrimination is just cranked up to it's highest level. I think I've only used this once or twice, so I'm not exactly sure where it cuts out at. Haven't really tested it, but I would figure it either goes up to about 172 (just below some zincs), or it might end at say 175 (just below most other pennies). Still yet, it might even go as high as say about 178. Anybody care to expound on this? I only know that I've used it a few times and it was useful, allowing me a nice quiet machine while I went through a metal graveyard and was able to find some quick coins while ignoring everything else.

The other forms of discrimination or notch is where things get complicated. Depending on what targets are most common at a site, the setting for one or either can Vairy greatly from site to site. The easiest of these to outline would be the notch program I developed for pull tabs.By doing some statistical graphing using an assortment of round and square tabs found randomly and in an unbiased fashion (not just digging certain numbers) at multiple sites, I was able to compile some averages in that respect to where they fall on the VDI scale.

You can see the "Splitting Hairs On Ring VDI Numbers" thread for more details on this, but suffice it to say that 84% of those tabs ranged from about 152 to 165 on the VDI scale. The less common numbers were 166 to 169, and I think 149 (or perhaps 14 to 151. While using a notch on the beach would be suicide, and directly contrary to what you are trying to do, I look at not using a notch at certain land sites equally just as insane to me.

Further, by careful calibration of the notch most of these tabs can be avoided while well over 75% of the gold rings can still be found. If you find a particular site has more tabs in say the 149 to 151 range than say the 162 to 169 range or vise versa, you can fine tune the notch to adjust for those accordingly. Some times it's interesting for me to be digging tabs in the 166 to 169 range a lot in an area, where as they are almost non-existent below 149 to 156 range, or just the reverse of that is true. When that happens a simple calibration makes life much more comfortable.

When setting the notch you can gauge it's range by probably about 12.5 digits, which happens to be perfect to kill tabs in the 152.5 to 165 range. The width of this notch might vary from one Sovereign to another, so I'd test it on targets to verify. I might add that it's always easier to set it properly by finding the highest number you wish to avoid and then slowly raising the notch until it just kills the audio of that target with precision adjustment. For some reason adjusting on say a 152 target with the lowest end of the notch in the hopes that it is now going to kill up to 165 isn't as precise for me, and I still haven't figured out why. By all rights if the target is 152 and I turn the notch all the way up and then slowly bring it down to 152, I should probably be killing up to 165.5. Often it does, but for whatever reason I've found it more precise and less hassle to raise it to the highest number I want to kill and not lower it to the lowest.

Another interesting thing to note about running a notch on land is that I primarily use it for ring hunting when the amount of tabs present would take me nothing less than a life time. However, I've also found it useful when old coin hunting on occasion when the number one target by the thousand present is tabs. It destroys my concentration when I'm hitting 5 or 6 of those things on every sweep, and that's when a little selective notch setting can kill that mid zone right where 99% of all the junk targets rest. If you are distracted or annoyed on certain days (you know how it is) then you aren't doing anybody good by forcing yourself to listen to the orchestra of tabs that those old coins are laying amongst. Interestingly enough, when using a notch when old coin hunting (which I do much more rarely than when I'm land ring hunting), my nickle count goes through the roof. I attribute this to me noticing and paying attention to all those potential nickle readings when otherwise I might not notice them because of all the hundreds of tabs talking in my ear that day. I figure for that reason alone so long as my nickle count goes up then I've got real potential to also dig a gold ring on those days when I'm purely old coin hunting, not to mention the potential for that ever elusive shield nickle I've been searching for. I swear, those things are my nemesis. Found plenty of coins that old and older, but that stinking nickle still won't show up.

Onto discrimination...Let's say you've got a spot where tons of foil and aluminum bits cover an area due to lawn mowers or other reasons. They often can sing to you in that 70 to 95 VDI range. Again, mostly when old coin hunting I won't use discrimination just like I won't use a notch, but there are days when I have had enough off all those lowest of lowest conductivity numbers. When that happens my usual routine is to raise discrimination over something in the 90's range until it just kills it. More often I use this while ring hunting, because once again the numbers show (see rings thread) that even if I kill things up that high (or should I say "low") with discrimination and run the notch as said, I'm still apt to recover most gold rings in the area purely by the numbers. I like to listen for those 110's, 120's, or 130's numbers to go along with the numbers in the nickle zone when looking for potential rings. Find the ones that sound round, soft, smooth, and give a stable VDI number swept from any direction, and you will have eliminated more trash (by sound and VDI reaction) while having the potential to dig some nice rings.

Still, on other days there seems to be an abundance of junk ranging all the way up to the high 130's. When that happens and life just can't get worse then raising the discrimination is in order. A good strategy I like in this situation is to bring it up to 138 or 139, as most nickles are going to read around 142 to 146. Still, if the trash is really bad in that range on a particular day then creep it up to say 143 because most nickles at least for me read between 144 and 146. Now what you've got is everything below nickles silenced for piece of mind when ring hunting on land in that baddest of places, but it's also a useful tool when trying to find old nickles in a sea of never ending lower conductivity junk. Try it, just like the notch for tabs you'll be shocked at how the nickles seem to breed at dead locations when your attention is focused like a laser on the only thing that pretty much can sound off in the lower range now- nickles.

As you can see, using discrimination and notch in relation to each other can offer some interesting possibilities. You can set the notch to a specific troublesome zone (which might not even be tabs in a particular area...For example, at a sit where a specific 158 to 169 shell or shotgun casing is present), and at the same time you can squeeze the "open window" of that notch by raising discrimination to where it narrows the accepted target zone into a very defined and specific range of numbers. That can be useful for looking for a specific target (such as a lost ring when you have something similar to compare signals to), or just to improve your concentration on desired numbers without being distracted by an abundance of others below and above that zone. Use your imagination here, it get's interesting when you consider the possibilities based on where the notch and discrimination are zoned to.

There are times when notch isn't going to be useful, as the desired number range you want to kill is say everything below let's say 170 on the dial. In a situation like that discrimination alone would be used and raised until it just kills that number. Now you've got 169 (tabs of some type) and everything else below that silenced. You aren't going to find any nickles and probably gold rings on that day, but at least you can hunt with some level of serenity and still have some interesting targets pop up. There are a lot of keepers that read 170 to 172 out there, just below zinc penny, or even at zinc penny. For that matter there is a lot of great finds that range anywhere from 170 to 180. Those "odd" numbers like 177 I just love to dig, because more often than not they are something good so long as the audio is smooth and the ID stable.

Final thought and in a sense a disclaimer. I can't for the life of me remember exactly where discrimination ends turned fully up. I've never really paid that close of attention to it. I just know that when things come down to either giving up on a site forever or at least walking away with my sanity, I've cranked that sucker up and hoped for the best. It seems that just about everything junk wise gets eliminated, and what few junk items remain up near the coin zone are easily discriminated by ear and VDI stability.

Also, while on the subject, keep in mind when using any form of discrimination or notch that good items right at the edge of those settings can break up and sound bad, being slightly broken off by those circuits. For that reason if you suspect something good but are thrown off by the audio, try lowering it a hair (or raising it in some cases concerning the notch) to see if it clears up for you.

One more final thing to kick around. Some machines in the past have featured dual notch controls. What's cool about these is the ability to set the high and low ends of that notch by turning two dials. IE: Raise one to 169, lower the other to say 120. Now they kill everything in between those two numbers. Too wide? Then adjust them down to kill as little as a 5 digit spread. That's a feature I always wanted. What I've been wondering and may start investigating is how the notch width (which is static) on the Sovereign is set. If that window range is calibrated using something like a resistor (better yet a variable resistor!), then it would be possible to increase or decrease the size of that notch by adjusting that component's resistance factor. Anybody ever check into this? It would be so neat to be able to add a small dial say somewhere on the GT's face plate and be able to adjust just how wide the notch is, then use the normal notch to move it to exactly where you want it on the scale like normal.

So I'd like to hear when, why, or even if you never use either functions on your Sovereign. Beyond that, are there any specific non-conventional numbers that you just love to dig for some reason?

 

[synthnut]

Once in the Discrimination mode , the Iron is dead .....I go up a little higher to scrim out foil .....Everything above that I have wide open for Gold and Silver and also for coins ..... I'm not into relic hunting ..... If I were into notching out pull tabs , I would use the notch feature , but I don't so I don't use it .... Notch works great for you with your Pull Tab ratio theory , but I don't follow your theory on that .... Too much that I've seen in that range , not only from what I have found , but others around me .....I would rather dig pull tabs than loose out on a chunk of Gold jewelry .......Jim

 

[gear box]

Well Critter, I'm glad you brought this subject up again. I asked a similar question a few months ago when I was just getting started with the GT and the response was you would loose gold when using notch. But I went against the grain of most and tried it anyway. The first place I used notch was at a fairground's that is loaded with pulltabs. I started using my machine here just like everyone suggested, notch off and disc. off. It just about drove me nut's listening to all the loud, obnoxious noise from pulltabs. I was becoming discouraged digging all the pulltab's. I didn't have a meter then and anything that went up a bit in tone I would dig and they alway's seemed to be a pulltab. I finally notched out the pulltab's and boy what a difference it made for me. The low growl of aluminum foil didn't bother me so I left the disc off. I was able to concentrate on what I was doing and when the high tones showed up I was pleasantly surprised to see wheat's and the occasional silver coming to light . It helped me as a beginner with the GT to learn the machine a little faster and made my time out with it more enjoyable. Then with the addition of a meter everything became much more clearer as to what I was really hearing.So, maybe by using the notch feature it could really be a good way for a new GT owner to figure out his machine a little faster. Conventional wisdom isn't alway's a help to everyone out there. Notch? Yes or at least sometimes. Disc.? Also yes, but not too much.
Good hunting Gary

 

[kered]

Once in the Discrimination mode , the Iron is dead .....I go up a little higher to scrim out foil .....Everything above that I have wide open for Gold and Silver and also for coins ..... I'm not into relic hunting ..... If I were into notching out pull tabs , I would use the notch feature , but I don't so I don't use it .... Notch works great for you with your Pull Tab ratio theory , but I don't follow your theory on that .... Too much that I've seen in that range , not only from what I have found , but others around me .....I would rather dig pull tabs than loose out on a chunk of Gold jewelry .......Jim

My thoughts entirely, you would also be surprised at the amount of gold that is in the Foil range too, thin diamond solitaires etc, just one of those and you detector is paid for.

We once had a quite heated discussion on here about the trash and cherry picking, if everyone took just a little home and dumped it in the trash things would get better, all be it very slowly, you have maybe 300 years of trash, we have thousands of years here in Europe so imagine what some places are like.

Another thing about disc/notch is it slows the machine down considerably, nulling in the case of the minelabs, (i know some targets will come through the null but not the deep goodies)constant nulling with the Sov really winds me up in heavy iron sites to a point I've found i prefer the etrac/explorer using iron mask/quickmask and run an open screen in some places, sounds like a machine gun and you get an ear bashing at times but its fast and very effective, if i could control the iron null on the sov i would run in this mode in some places rather than disc it out,(its not the same as All metal as you still have sound ID) if you can hear it you can also hear whats alongside/underneath/on top of/ or between it.

 

[synthnut]

Kered,
Try 2 tone Ferrous on your E Trac .....No nulling , everything comes thru.....Everything above the 17 line on the Ferrous scale ( iron and such ) is low tone........Everything below the 17 line is high tone .......EASY and FAST !!.....Listen for high tones and then check your numbers .....

Crtter ,
If the notch feature was a 2 knob function , I would use it ....One knob to bring you into a certain range, and a 2nd knob to either narrow or broaden that range ....For example , lets say that I wanted to go into the pull tab range ......I dial one knob to get me into the range .....Then I take the 2nd knob and if I want to take out 2 numbers I can ....If I want to broaden my notch, I could broaden it to 10 numbers ....In other words have the notch adustable in width from 1-10....... This way for example if I'm in an area that has a bunch of number 145/146 pull tabs , I could dial dial that in ....If my tabs were in the 145 to 149 range , I could do that too if that were the case .....The way the notch is now , it's too broad of a range for me ....It's too much discrimination , and as Kered says , you would really be hearing a bunch of nulling going on and you would be waiting a while to hear your threshold .....Some sites are bad enough with all the iron .... It almost sounds like you're in silent search mode ..... What would be nice to see would be something similar like the 2 tone Ferrous mode on hte E Trac .....I don't see it as hard to implement , but then again, I"m no engineer ..... 2 tones that's it ......Take all your targets and divide them up into 2 tones .....Those with a lower Ferrous go to one tone, those with a certain amount of Ferrous and higher , bo to a higher tone !!..... The machine runs wide open , but you are not hearing as many confusing tones as you do in All Metal ....This would be good for relic hunters also ....They would be llistenning to low tones , and us coin/jewlry shooters would be listenning for high tones ...BTW, I don't think that there is a better machine when hearing targets thru the null than the E Trac ....It's amazing to say the least !!.....I stand by my earlier statements tha the E Trac and the Sovereign are the 2 machines to own !!......Jim

 

[Critterhunter]

I usually hunt the sand and just dig everything. But there are times I find myself detecting in the dirt. I make sure the toggle is in discrimination. Good-Bye iron. I'm not a Relic man. I don't want to deal with iron at all.
Since the beginning of my detecting days (Young boy) I have only ever dealt with two kinds of trash that I really felt I needed help with. Foil & Pull tabs.
Discrimination knob kills the foil.
Notch kills the pull tabs.
Oh I have been in bottle cap spots. I just dig em. Can slaw? That can be almost any VDI. Usually all over the place. No way to really reject it.

So to me Discrimination means iron and foil and notch means pull tabs. I use them when I have to.

Very true and to the point. Most of the time when I use either forms of discrimination those are the reasons why. It mainly comes down to just how bad the area is in terms of how much of it I use. Like I said, one very powerful way to really zone in on nickles is to raise the discrimination to the very bottom of where nickles read for you, then adjust the notch so it bottoms out at the highest spot nickles also read. Now you've got a very tight window where anything low that sounds off is probably going to be a nickle, might be a gold ring, and chances are isn't going to be yet another piece of trash. Further discriminate these low tones by looking for ones that are stable in ID, perhaps only changing by a digit or two depending on which way you sweep over them, and of course has nice "round" smooth sounding audio. I'm amazed at how this machine pops old crusty nickles out of spots I've beat to death with other detectors. With discrimination brought up to say about 139 (141 or 143 makes it even more choosey about wanting good nickle signals), and the notch brought down to say 148 or 147 (right at the top of my nickle zone, but different sites vary the nickle numbers some times), you've got a very tight window where for the most part only true good nickle hits are going to sound off. Also, with it said at say 147 then the top of the notch is at 159.5, eliminating most tabs for the most part, but also leaving everything about 160 to sound off. Often some of the good non-conventional targets are at that number and above, and it's rather easy to notice what the left tab numbers are in say the 160 to 169 range. Ignore the common tab numbers in that range for a specific site and dig everything else, even if it's only off by 1 digit than a common tab number.

 

[Critterhunter]

Great thoughts and theories. Keep'em coming! One other potential use for some mild discrimination is when a site has a lot of hot rocks or tiny bits of junk, even if it's not foil, or other things such as a lot of iron that keeps sounding through slightly. When that keeps happening to you and is becoming a distraction pay close attention to what the VDI keeps bumping up to in the low range here and there. Now raise discrimination over one of those problem targets to where it just kills the audio. You'll find it smooths things out much more for you, though you should probably try Iron Mask OFF first to see if that works better for the problem. Let's not forget that Silent Search can also be an effective tool for smoothing out these little chirps when things get tough.

On my Explorers I thought Learn Reject and Learn Accept was going to be the be all and end all to discrimination on a metal detector. I quickly found out that the resolution was much too fine in terms of how the machine saw one target from the other on seemingly identical items. It made trying to pin down and eliminate something like a pesky pull tab much more problematic to me than it is on the GT. I don't want 10 possible spots the same tab can be put in based on it's slight ferrous or non-ferrous variations from one identical tab to another. That's where the possibilities get much to infinite as to which tab goes where on the scale, and trying to develop a tab program to cover all those "dimensional" variations each one could have made things a blurry mess. Still, most other machines on the market had too way low of a resolution in the low and mid scale of target conductivity to offer me much in the way of potential strategy to split hairs on that trash versus rings. The Sovereign's resolution seems just about perfect to me. Not too how or "diverse" to make chasing down unwanted targets like a wild goose chase, yet not too low of resolution to not be able to show me the finer differences in say nickles and the lowest (about 148 or 149) pull tab numbers. Combine all that with the most telling audio on the planet and no wonder it's a legend in finding gold rings. It isn't just about it's depth ability on those rings, it's all the reasons above.

 

[synthnut]

Silent Search seems a little drastic to me .......I like to hear most of what's going on under me , but I will tell you this .....I am really pretty spoiled by useing Iron Mask OFF ...... It cleans my signal up just enough to allow me to hear my targets better and the Sovereign STILL masks pretty darn well on it's own .... Maybe it's the filsters in the Discriminating mode that are just THAT GOOD !!......?????......Jim

 

[Critterhunter]

Drastic situations call for drastic measures. There are rare times when uneven ground (causing uneven coil placement) such as in crop fields or tilled dirt for instance makes the machine a bit noisy with the coil moving up and down and such. There are other situations that cause tiny little but no less distracting noises. In those cases running in Silent Search can really make life worth living again. I like using it when I'm hunting the woods and I'm not apt to here any sounds for a LONG time. In those cases being constantly "hummmmed" to sleep by the never changing threshold gets to wear on you. I then throw it over to silent search until targets start showing up. Besides, it saves on battery life. Even in silent search it's possible to know when you are getting into an area that contains iron, as the machine will slightly sound off here and there. When that happens it's back to threshold mode to work the area.

 

[kered]

One of the reasons i swapped out the F75 was the silence in disc mode, i'm hooked on the threshold as it tells so much, thats why i like the whites DF PI too

 

[synthnut]

I get plenty of Threshold changes where I hunt ....I NEVER get bored of no tone changes ......My area is just he opposite .....Jim

 

[Critterhunter]

Most of mine are noisy too and I prefer a threshold. It's just at certain deep woods locations where I haven't come across areas of human activity yet, and might not for some time. On the other hand, I should toy with running All Metal track (because I travel long distances before hearing something) and then use Silent Search in that mode. That way I would for sure notice any iron I've gone over while scouting out the next spot, where as in discriminate it often takes several hits of iron before something sounds through. Besides, who knows, I might start digging those lone iron signals off in the woods in the hopes of a meteorite I can retire on. Anybody else tried their hand at that? I've been meaning to do that. So long as you are way off in the woods at some remote corner there's a good chance you aren't going to be digging nails and other junk that reads iron like a meteor.

 

[synthnut]

I haven't done a lot of messing around with my Sovereign yet so bear with me when I ask some of these questions ......

If you hunting an area where there are few targets , and you don't want to hear the constant threshold , can you bring your threshold to the point where it just goes away and still hear your targets ....When I hit my Silent Search switch , it lowered the volume of everything but it did not take it completely away .....If turning down the Threshold to make everything go away at this point , will targets be heard ? .....and if they are heard , are they heard as loud as they were before switching to Silent Search ?

 

[synthnut]

Kered ,
I heard that the F75 was a total chaterbox .....It rarely gave you a break !!....??????.....Jim

 

[Critterhunter]

Lower the threshold a tad tiny bit lower than it normaly is so you can just hardly hear it, then flip over to Silent Search. It's a special mode that is meant to make sure any tiny little sound off will break through the silence, which is much different than just turning the threshold down on any machine to where it goes quiet. Silent Search makes sure the tiny soft sound offs will bust through, so don't just turn threshold low enough not to hear in normal threshold mode. There was discussion a while ago about in theory Silent Search boosting deep signals by going into that mode and then bring the threshold back up to where you can just hear it. Nobody got around to testing that theory. Some day I will.

 

[kered]

Jim, The F75 is a chaterbox if you have too much sens or a lot of EMI in the area as its very prone to that, similar to pushing the sov (or any other machine for that matter)over the limit with sens, you get falsing. A good fast, deep, light machine but i didn't like the way it beeps, just a pure electronic beep, no roundness or feeling in the sound if you know what i mean, just a plain dull beep for each number. Very good for what i got it for, fast clad hunting on the dry amongst thousands of nails, but just not my cup of tea/coffee. I know a good few that have changed from the Etrac to the F75 and are delighted(although i can't for the life of me think why, each to his own).

Soz for the offtopic

 

[synthnut]

Critter,
Thanks again for the information ......Bringing the deeper tones up to snuff so to speak , almost sounds like some sort of a compression scheme ........ When recording music , you use a compressor to somewhat squash a signal ...It brings signals to a tighter dynamic range .....Softer tones get louder and louder signals quiet down more ..... A leveler so to speak ....Then when everything is pretty much on the same level, you can turn up the volume to hear everything more clearly ...low and high volume instruments are now at a level hearing field ....Jim

Kered,
I would guess that the guys who switched were coin shooters on dry land that had no beach around them to hunt , and liked the fact that the F75 responded so much faster than the E Trac .... The E Trac with it's micro processors take more time to respond than the F75 which I think has everything going thru a chip and responds much faster than the E Trac ....Since I have a larger variety of places to hunt includeing land a sea, I opted for the E Trac and have not looked back .....Single frequency machines don't cut it in the wet sand ....Jim

 

[Critterhunter]

Kered, if the F75 is doing that to the audio making it sanatized then the F75LTD or T2LTD is out of the question for me. I had been considering adding one of those to my line up based on how deep they will go at least in non-mineralized ground (almost as good as a Minelab from what I hear). As I've said in the Compare the Competition thread, I don't care for machines that only produce a "beep" type response with no meat or traits to it that I can analyze. That's one of the key things I didn't care for on the Explorer, though it wasn't as bad as some machines in that respect.

Jim, just remember if you try Silent Search to first in regular threshold mode lower the threshold a tiny bit more than you probably normally hunt with it, to the point where you can just hardly hear it at all. Then flip over to Silent Search and it should be silent now. The theory is that if you go to Silent Search mode after doing this and then bring the threshold back up again to where you normaly hunt at in terms of volume Silent Search is now acting in some way like an audio boost mode. It will take the softer/fainter/deepest of signals and make them more robust (louder) than they normally would be in regular Threshold mode. I have not tested this theory but same day will.