If I now a site has very few targets and that they might be deep, I prefer to hunt in All Metal with a T2, Omega or Gamma.
If hunting in a motion Discriminate mode, and if I am mainly after coins, and if the coins are usually going to be relatively shallow and in abundance, such as at a tot-lot or playground or around picnic areas, etc., then I like to use a multi-tone approach. That would be 4 on the T2 and d4 on the Omega or Gamma.
If I am searching a site where I anticipate targets being deeper, and by that I mean 'mid-depths-to-deep" regarding coins and such, then I like to use either a 1+ or 2+ on the T2 (usually 2+ because I accept Iron most of the time), or the d2 Audio Tone with the Omega or Gamma. Why do I like this choice? Because, as I stated, I usually hunt with all metal acceptance and the '2' selection lets me audibly classify most Ferrous Vs Non-Ferrous targets.
Better still, when I am looking for the deeper targets the '1' and '2' Audi Tone selections will provide me with better overall depth and signal responsiveness, allowing me a better chance of hearing the weaker, deeper, fainter signals than if using a processed 3 or 4 tone ID setting.
Is that close to what you were wondering about?
Monte