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Why I use Stereo Mixed Mode

Justinian

Full Member
Joined
Nov 8, 2010
Messages
248
Location
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I use the V3i, and I have had several people ask me what program I hunt in. When I explain that I only hunt in Setero Mixed Mode - they want to know more. So here's my long answer.

First – where I hunt, all non-ferrous objects must be dug. Any Positive VDI number is a potential good target. I am not concerned about pull tabs and aluminum bits of trash. I have Celtic and Roman gold to watch for! Plus medieval silver, and gold can come in from VDI -2 to +30.

I only hunt in Stereo Mixed mode, which causes an All-Metal (AM) channel to sound in my left ear and the DISCrimination (DISC) channel in my right ear. I also have the machine set so the audio’s VCO and modulation are on. This means the sound increases in pitch in the AM channel and volume in the DISC channel when an object has a stronger signal (usually due to shallow depth).

Now the machine will work as follows:

1. Iron objects will only sound off in the LEFT ear. Even shallow iron will not sound in the RIGHT ear. SO if I hear a LOUD sound in my LEFT ear ONLY, it is 100% shallow iron. I move on (unless I am looking for iron relics).

2. Good (Non-ferrous) objects will make a sound in the AM channel too – but only a strong signal will cause the DISC channel to respond. So if I hear BOTH AM and DISC sounds – I dig!

Now here’s where these settings kill the Coin and Jewelry program:

3. Any metal (including fine silver and gold) can come back with a negative VDI if the signal is weak (deep) or if the ground conditions are bad. This makes some good objects appear like iron. So if I hear a faint sound on the AM channel (left ear) and nothing on the DISC channel (right ear) – I have to dig a bit to get a better signal. I want to either hear the same sounds as in #1 above, #2 above. Until I get either one of the above, I keep digging.

Additionally – there’s the issue of near misses (where the center of the coil is not directly over the center of the target). You will not get a strong signal on deeper objects. Many of these signals are too weak to even set off the DISC channel at all. This means near misses often never make a sound when you hunt in pure DISC channel audio such as Coin and Jewelry. Read that again. You walk right past them – never knowing how close you are to a good target.

Add to that the fact that some targets will respond better at a faster or slower sweep speed. You really do not know if what is the IDEAL speed to pick up a target. You may be going too slow, or too fast to get a good reading on the DISC channel. But the AM channel has no such problem! It can hear it at any speed.

And finally – the AM channel has NO such thing as recovery delay. None. It hears it all regardless of how close the objects are to each other. Recovery Delay is only a setting for the DISC channel.

So to prevent this loss – the AM channel of the Mixed modes allow you to hear weaker signals even if you are not directly over it. It’s that sensitive. So when you hear a weak signal ONLY on the AM channel (left ear for me) I know I may be hearing a near miss – so I go back and re-sweep that area from two directions to make sure my coil gets right over the top. Then I use the techniques above (1-3) to determine if it’s a target I want to investigate further.

Similarly, the AM channel will respond at ANY sweep speed – so you can then re-sweep over a target that you only heard in the AM ear – and try a little faster or a little slower sweep to try and improve the signal processing in the DISC channel. I tell you - about 1/3 of all my ancient coins I have found were heard ONLY after I re-swept the area at a different speed. Had I not had the AM channel to tell me something was even there - I would have walked right on by.

All this means is that you get many more chances to NOT MISS a good target. This is why those who learn to use the Mixed Modes well will kill other detector users in the field.
 
A great writeup.

I usually hunt in just plain mixed mode. I think I will switch to stero to see how that works.

Thanks for your contributions!
 
When I run in Stereo Mixed Mode I lose pinpoint audio. It returns if I switch to regular mixed mode, all metal or discriminate. Have you experienced this problem? And if so, how did you remedy it?
 
No, never had that problem. Pinpoint works as normal in Stereo or in regular mixed mode.
 
No, never had that problem. Pinpoint works as normal in Stereo or in regular mixed mode.

Hmm, must be something wrong with either my detector or my headphones. I will try another pair and fiddle with settings to see if it just a biological detector interface issue.

Thanks for your response.
 
Pinpoint Audio has an option to have it set to the same as the Search Audio settings. Check that out and see if that is the case.
 
Pinpoint Audio has an option to have it set to the same as the Search Audio settings. Check that out and see if that is the case.

I will give it a look this afternoon. In some testing I did last night, I found that the PP audio was there, but, really faint. Odd that it happens only in Stereo MM. I will look for this PP audio setting.

Thanks!
 
So if I understand you correctly, your are running the stock c & j program and changing the search mode, VCO & modulation?

Is the pinpoint mode matched?
 
When i had the V3i I hunted in mixed mode, stereo just felt strange. Either mixed mode was essential because disc lags before it beeps when going over a target. If you set up the delay right you will hear the disc beep right after the all metal portion beeps.

I miss the V3i, but i just couldnt get it to give me accurate target ID past like 6".
 
Looks like I am going to have to experiment with "Audio Boost". I am guessing that in SMM, the PP audio signal is being split so it is much weaker in each ear. So, I will play around with the various volumes at various AB levels to see what gets me my PP audio where I want it to be.

One would think that if PP is being split into two signals, the signal strength would be roughly half of what it was in a single signal.
 
Wow, glad I knew that, is there a switch for that?

There is a switch, but it doesn't actually switch to full stereo. I think It just mimics what is in right ear. If you turn the switch in the up position, things get really wonky with VCO. Makes it very, very faint.

If I run in Stereo mixed mode with Mixed in left ear, DISC in right ear with the switch down, I hear DISC in both ears. If I flip the switch up, I hear MM in both ears. In both cases, the VCO is very faint.

Now, if I perform the same experiment in regular MM or AM, with the switch down, things work as expected. I hear the same thing in both ears. If I flip the switch up, the AM and VCO gets very faint.

I have been thinking of getting the Whites Wireless. This incompatibility just might speed things up.
 
I don't know how I never saw this post before but it's an excellent post.
Thanks for being so thorough in your explanation.
 
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