As sube suggested, "3" is indeed the "optimal" recovery speed setting, for the Equinox 800, from the perspective that -- from an engineering standpoint -- it's where the machine is running at its "most tuned" state (per an engineer involved with the Equinox design). As I understand it, what is affected, when adjusting recovery speed, is the length of the audio report. SO -- if you choose a higher recovery speed setting, the result is to shorten, or "clip" the audio reports, and as such, you can therefore perhaps HEAR more "separation" between tones emanating from closely adjacent targets. Thus, if you are in dense trash, and there are multiple targets lying in close proximity, these targets may be reported by the machine more "clearly" or "separately," at a higher recovery speed setting. This can make it SOUND like the machine is processing things "faster," but it's actually just an adjustment to the audio reports themselves, not the actual "speed" with which the electronics of the machine -- the "architecture" of the unit -- are functioning.
The way I understand the concepts, I think an analogy could be made to illustrate what "recovery speed" does, by using an example from music. In music, a musical style where the singing/playing of notes is performed with each note being "abrupt," or "short in duration," and thus clearly separated from the notes to either side of it, is called "staccato." The opposite style, called "legato," is where instead of short, choppy notes as would be sung/played in a "staccato" piece of music, the notes are more elongated and "smooth," without clear breaks between the individual notes. Things kind of "blend together" in a legato piece of music, as opposed to having clear, brief breaks between the notes, in a "staccato" piece.
These two ideas -- staccato and legato -- are, as I understand it, essentially what recovery speed does. A setting of 1 on the Equinox, is the most "legato" setting, whereas a setting of 8 is the most "staccato" setting. Thus -- choosing a higher recovery speed, where the tones are "clipped," can at times allow you to hear the individual tones (targets) as more clearly "separate," and thus possibly permitting a better chance of you recognizing that there are two adjacent targets beneath the coil, as opposed to when the two tones are "smeared together" into one, as my happen at lower recovery speeds...
Steve
