if you have Mixed Mode active, both the Coin & Jewelry and Relic programs are using the same motion discriminate mode of operation. Thus, the Dual control is only adjusting the Discrimination point for either of these operations and not the SAT speed. The variable SAT speed is a function for use in the All Metal search Prospecting mode.
The MXT, and M6, have been listed as both a 2-filter and a 3-filter functions in different White's literature, and while both approaches result in a slow-motion/quick-response method of operation, the 3-filter type design, as I first experienced a lot with the Compass Scanner series in the late '80s which used a 'Vari-filter' or 3-filter concept, can allow a faster sweep in more challenging iron mineral ground than a traditional 2-filter type of design. I get that type of excellent performance from the MXT.
It used to be that the 4-filter detectors, like the XLT or XL Pro or earlier 5900 & 6000 Di Pro SL models, had the advantage of being able to work at a faster sweep in more mineralized ground than the simple 2-filter designs. While there still can be some challenges in ugly environments, I found the MXT's to work great if I happened to use a more brisk sweep speed. However, I usually reserve a faster sweep approach to site coverage for those times when I am absolutely limited in access time.
As stated below, you can get excellent performance with the MXT using only a slow-to-moderate sweep speed. One that is comfortable. You don't need to crawl, but just take advantage of the MXT's quick-response with a slower sweep, especially if using something like the 5.3 Eclipse search coil, and you will be able to hunt more comfortably. At the same time, you'll hear more good signals in masking trash environments that could be missed if you sweep too quickly.
Monte
