Sound Tutorial

[mcjtom]

Is there some basic summary of sound interpretation (Minelab flutty tones processing perhaps) that could help me learn how to interpret what I'm hearing?  For instance, hearing iron burp at the edge of the coil for b-caps, or 'round' vs. not so round sound etc.?

[Chase Goldman]

Such audio ear training aids do exist but mainly for detectors that are audio only such as the Excalibur and GPX.  They are less common for induction balance detectors that have audio and a visual target ID display.

Your best bet to train your ear is to simply use live targets of both common junk and desired treasure either buried in a test garden or scattered on the ground.  If using scattered surface targets, you can add some realism and guesswork to the ear training by attaching the targets to pieces of cardboard (so you can invert the cardboard and not be biased by your visual of the target).  This method also helps you practice pinpointing and coil control techniques by mixing it up and not attaching the target dead center on the cardboard and allows you to dynamically set up potential mixed target masking situations by overlapping the various target boards.  You can further mix it up by using wood blocks or styrofoam/memory foam structures to vary the target height in relation to the coil and in relation to each other to emulate in ground target depth differences.  Let your imagination run wild.

By practicing in this manner you train more than just your ear, you can also practice your swing and coil control technique, pinpointing skills, integrate the target audio with your visual target ID display, and better train your ear/brain "muscle memory" because you are practicing in an environment that most closely replicates your actual field conditions. 

At the end of the day, however, the best traing aid is getting actual field experience gained by accumulating swing hours with your machine under real world detecting situations.

HTH

[mcjtom]

Many thanks for this.  I found this primer on the topic, which reads reasonably: https://nwdetectors.com/blogs/news/how-to-avoid-digging-iron-trash-with-the-minelab-equinox-800

A question(s) on Minelab tones (Vanquish 440 of course, but it's probably not that different in Equinox in limited tones modes).

What does the loudness of the sound when sweeping the coil indicate?  I'm not even sure anymore if there is a loudness involved or it's just on and off square sound amplitude...

What is the logic behind setting the mid/high tones breakpoint at ID 17/18?

[mcjtom]

Kind of vaguely related to the sound questions above: I found a 'target' in dryish ocean white beach sand.  ID 17/18, round, solid signal from all directions.  It was a paint can lid (some 20 cm in diameter, ferrous, perfectly horizontal, a little rusty, but it was some 50 cm (20 in) deep! Good lesson.

[GB_Amateur]

On 12/27/2021 at 11:35 PM, mcjtom said:

What does the loudness of the sound when sweeping the coil indicate?  I'm not even sure anymore if there is a loudness involved or it's just on and off square sound amplitude...

In Park 1 on the ML Equinox, which is what I use 90% of the time, there is a volume dependence on signal strength.  Lower volume amplitude indicates a weaker signal.  That's a good indicator that if it's a coin, it's deeper than an otherwise equal dTID, but louder tone.  The so-called 'Depth Gauge' (actually 'signal strength gauge' is more accurate) on the Eqx is correlated to the volume amplitude but I wouldn't swear that it's a perfect linear relationship.  I use both methods myself.

Regarding other modes, in particular the Gold Mode (Eqx 800 only) is a Voltage Control Oscillator (VCO) like volume response.  The manual says:

On 12/27/2021 at 11:35 PM, mcjtom said:

What is the logic behind setting the mid/high tones breakpoint at ID 17/18?

I didn't watch the video you linked so I don't know why they did that. I like to set some of my breaks in 5 tone mode to correspond to targets I especially want to get audio responses on without having to look at the screen every time.  For example, our modern USA 5 cent coins (aka 'nickels') have a sweetspot of 12-13 on the Eqx in my soils.  I have one tone region top out at 11 and another at 13.  Maybe I get a pure 12-13 tone, but if I get a coin traversing the low border (e.g. 11-12) I will get an mix of medium-low tone and high tone.  If I get a coin traversing the upper border (e.g. 13-14) I'll hear a mix of high and medium-high tones.  The 13-14 is usually a modern pulltab so I typically just move on (unless it's a weak signal).  The 11-12 is often on older piece of pulltab (the beavertail only -- missing its ring).  I don't necessarily ignore those but it does often save time to hear the transition dTID's without having to look at the screen.  Sometimes the 'outside' dTID part of the signal is so subtle that it won't appear on the screen but you can still hear it chirp.  E.g. the screen shows 12 every time but mixed with the high tone is a bit of breakup, indicating (I think) some lower TID mixed in.

(Addendum for clarity:  ) Only the 800 model (not the 600) allows you full freedom to change tone breaks in 5 tone, as I describe above.

[NCtoad]

11 hours ago, mcjtom said:

Kind of vaguely related to the sound questions above: I found a 'target' in dryish ocean white beach sand.  ID 17/18, round, solid signal from all directions.  It was a paint can lid (some 20 cm in diameter, ferrous, perfectly horizontal, a little rusty, but it was some 50 cm (20 in) deep! Good lesson.

This is a difficult situation with the nox ( and probably most other detectors). You get a good sounding signal that should be an average to fairly deep coin, but it ends up being a very deep large object.  Sometimes you can tell this by using the pinpoint function and trying to size up the target, but when a large object is so deep it still may pinpoint similar to the size of a coin that’s not so deep. You can also try raising the coil as you sweep over the target and if it fades out quickly it’s most likely coin sized.  If you’re still getting a decent signal with the coil five or six inches or more above the target it’s most likely a smashed can, or a paint can lid, etc.  However, a very deep smashed can or,  in your case, a paint can lid at twenty inches will fade out quickly just like a coin that’s not so deep.  So it’s hard to tell the difference.  I still occasionally get fooled on smashed, deep, aluminum cans even after 3 and a half years of using the nox.  

[kac]

Learning the nuances on any machine just takes time in the field digging and what you hear. Analog machines are still better for sound but takes a long time and a lot of digging to be competitive with them so your not digging so much trash.

Best way to learn is get out there!