The Nokta / Makro Impact, Kruzer and Anfibio models do offer other search modes that provide more than only a 3-Tone audio. They are more expensive and more featured models. Personally, I never used or enjoyed anything but a 2-Tone and 3-Tone Discriminate mode. My Nokta CoRe and Relic and Makro Racer 2 all feature a 3-Tone mode, and additionally they have a 2-Tone mode. They also have a Beach mode that can be adjusted for 1-Tone [size=small](no ferrous range accepted)[/size] or 2-Tone. The Relic and Racer 2 also have a slower-sweep and deeper-detecting 'Deep' mode which is also 2-Tone when ferrous is accepted. So ALL the Disc. modes on the CoRe, Racer, Relic and Racer 2 are adjustable for 1-Tone or 2-Tones with the exception of the 3-Tone mode which uses a 'processed' audio.
ALL of the 2-Tone Disc. modes can provide better 'depth-of-detection' than the 3-Tone mode on those models, and Why? Because the best use for a multi-tone audio, such as the processed 3-Tone, is when searching trashier sites, and for most typical 'Hobbyists' they are going to be hunting parks and playgrounds and picnic areas and all sorts of places, mostly associated with an urban environment, where they are going to be dealing with trash. Generally more modern trash, such as pull-tabs and pry-tabs, bottle caps, screw caps, discarded foil and other common unwanted junk. Also to note is that most of the commonly hit urban places have coins that are located relatively shallow, and with the trashier places, that masking effect will prevent achieving any useful depth anyway.
I use my CoRe and Relic and Racer 2 with their settings 'saved' to start-up in 3-Tone mode because, generally, I'll grab them to search very littered places. The racer 2 w/7" Concentric coil is in my urban Coin Hunting Team but I can use it for 'scouting' unknown areas as well. My CoRe keeps the small 'OOR' DD mounted and my Relic the small 5" DD is attached because they are my most-used units for hunting terribly-littered ghost towns, homesteads, RR depot and siding sites, stage stops, old encampment and fort sites, etc., where I especially have to work in dense nail and other ferrous debris. I can't get any depth due to the very dense amount of junk, so the 3-Tone often works well to help isolate some potential keepers mixed in with the ferrous trash.
But out on the fringes of the older sites where it is more open and there are fewer iron targets, or where the primary iron encountered is nails or cut wire, the 2-Tone mode handles the junk well and passes along a better, clearer audio response on non-ferrous targets than does the 3-Tone mode with the processed audio. I can also take advantage of the 2-Tone mode's improved depth-of-detection. The same holds true for mode selection when hunting a large city park or grassy school ground, or private yard, parking strip or other easements. That's the mode that also works better for other wide-open places such as a plowed field, pastureland, in the woods or on a beach, be it salt-water or fresh-water.
So, a processed audio 3-Tone mode makes the better pick for trashier sites, especially modern uses like near a picnic area and such, and is associated with hunting an urban Park like setting. Thus, the Simplex[sup][size=medium]+[/size][/sup] offers a 3-Tone audio Park mode. But if you want to get better depth-of-detection in a more open and sparse-target environment, such as an open field or out in the middle of a park or school ground, or hit an inland or coastal beach, you can benefit from a 2-Tone audio in a deeper-seeking mode. The other models I referred to offer that in a 2-Tone or Beach or 'Deep' mode choice, and the keep-it-simple Simplex[sup][size=medium]+[/size][/sup] provides that in either the Field or Beach mode choices.
We know that as the coil-to-target distance increases the amount of receive signal is going to be weaker, and we see that in the loss of better visual Target ID at depth with almost all detectors, even though we can still hear an audible report for the deeper targets. Well, that loss of receive signal strength doesn't only make it difficult to try and process a proper, functional Target ID, but it also makes it much more difficult to produce a 'proper' processed audio tone on a multi-tone [size=small](3 or more tones)[/size] Disc. mode. So, again, for hunting places to achieve a workable good audio on mid-depth to deeper targets, a 1-Tone or 2-Tone non-processed audio function is, by far, the better option.
The Simplex[sup][size=medium]+[/size][/sup] removes the excess selections that might be on some higher-end models and keeps things very simple and very practical. Park for a typically shallower-target hunt in 3-Tone, or Field or Beach modes for those who are dealing with less trash, more open areas, and want to achieve improved depth, all using a very workable 1-Tone or 2-Tone Audio response.
If someone likes to have more Audio Tone Mode choices, they just need to spend a little more $$$ to get a higher-end, more-featured model. For me and my needs, I enjoy my Nokta / Makro models that are more basic and to-the-point so that I spend more Time out hunting and finding stuff. Less tinkering.
Monte.