Audio Gain

[Cody]

The gain control is illustrated and explained on page 52 and figure 5.16 and 5.17. It is about a clear a mud to most folks but here is what they are trying to show. Look at my attached illustration. The red line indicates where Audio Gain is set. If set to 10 then we have a very steep red line. The blue lines represent what we would hear for weak and medium detected target signal strength. If set to 5 the red line has a more gradual slope so the blue lines are further apart on the signal strength line. The signal strength can change more with less increase in amplified signal loudness.

What this tells us is if we have Audio Gain set to 10 then just about any signal is going to blow our ears off. That is where tiny shallow bits of trash drive us up the walls. Ten is good in nice clear ground but is a real bear to deal with in heavy trash. With good headphones I have no problem with 4 to 6 in just about any situation. There is a nice clear high sound for deep coins that is noticeable softer than a shallow target. This is another way to tell depth. The strength of the audio in conjunction with the depth indicator makes it very easy to tell how deep a target and using the ID of the electronics we have a very good idea if it is a deep keeper.

 

[Cody]

Sorry about not getting the illustration up the first time. If the illustration makes and sense, I hope it does, we see that if audio gain is set to 10, the steep slope on the left then a very small change, the blue lines for changes in detected signal strength, there is a large increase in detected signal amplitude. This tells us that we cannot tell deep targets from shallow ones very well. The illustration on the right has a less steep slope in red but the detected signals can have to change considerably to get the same audio signal amplitude of the detected signal. This makes is easy to tell if we have a deep signal or a shallow one.

This illustrates the problem with an audio boost type of circuits where all signals sound the same. The idea is to not miss weak faint deep targets by unfortunately we blow the shallow signals way too loud.

I don't care for audio boost so don't use DEEP ON as that makes the problem even worse. Deep will kick up the faint deep targets and also the shallow tiny pieces of trash metal. If DEEP is on and Audio Gain is at 10 and we are in heavy trash we are going have a heck of a lot of sound to deal with. If limits is maximum so we have very hit pitches to deal with then it gets a little too much. I have always been against the idea of setting a detector like that in most conditions, for myself, simply because see not reason to blow my ears off with useless sounds. Again, in clean ground we may want to do set the detector that way but it comes down to what floats one's boat.

 

[GraveDiggerMax-VaBch-Va]

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