Deepest program for XP deus 2

[Ism]

For raw depth I find Relic or Goldfield will hit the hardest in clean ground, but Fredneck, I will try the D2 Mono at 17 kHz next time out.

For the D1 and most likely D2 in mono, 4khz is best for raw depth on high conductors like copper or silver coin sized targets
If you want to find deep non-ferrous low conductors like gold, platinum, nickel, or lead, then 12-18KHz is best.
12KHz is a good compromise for both high and low non-ferrous conductors.