Hi GroundScanner
The sounds you are hearing in MMP are normal. The left phone in your case is the all metal channel picking up all metal in the ground, it will be a vco sound. If you have vco unchecked in all metal it will sound like a lightsaber depending how you have it set. Sounds in all metal are adjustable. The right phone is your discriminate side and will sound off a tone for all vdi you have accepted in Discrimimnation. These tones also are adjustable to however you like them.
Audio > Tone > VCO Threshold = can change sound of all metal side, left phone
Audio > Stereo Mixed > VCO = checked will sound like vco, unchecked will sound like lightsaber in left phone depending on your setting
Audio > Tone > VDI Tones > Custom > Edit = you can set any tone for any vdi or turn off a tone for any vdi, right phone
I use Expert Menu to do all these settings. Great thing about the V3i is that you can change so many settings to your liking.
In MMP go into Audio > Tone > VDI Tones > Custom > Edit and you will see by scrolling all vdis and tones and they are all adjustable by using the scrolling arrows on the v3i dashboard. Hope this is helpful. Good Luck !!