XP Deus Program Settings, Features and Modes Explained, page 9
IRON VOLUME: Function and Usage
Levels: 0 to 5 (Page 12 in User's Manual)
Iron Volume (or Iron Level) allows you to control audio volume of the low-pitched tone which you assign to iron targets. If you do not want to hear too much of low-pitched grunting of iron nails and other ferrous junk, set the Iron Volume at 0 just to hear responses of higher tones.
However, if you employ least Conventional Discrimination (not Tonal Discrimination), with the Iron Volume set at 0, you will hear a lot of iron falsing ("clipped" or inconsistent high-pitched audio responses) and would not be able to determine whether a target is iron or not unless your ears would have already been trained to do so (it takes at least one metal detecting season).
The Deus is a 'tone' detector, therefore, its features and settings are designed to help a user identify "questionable" signals by their sound characteristics. Success depends on how well a combination of Iron Volume, Reactivity (described on next page) and Silencer (page 12 of this article) is optimized to make coins that are positioned near, above and under iron objects "sound off" with clear signals.
If the Iron Volume is set on high levels, 4 or 5, the sound of iron may be too loud and "overshadow" short high-pitched responses to tiny coins or coins partially masked by iron. If the Iron Volume is set on 0, you would not hear low-pitched responses to VALUABLE targets that are buried deep - at the limit of the Deus' detecting range. Such responses may be broken or chopped a little and have light iron buzz to them. This is why, if you search for non-ferrous targets, you should set the Iron Volume at 2 or 3.
Medieval Coins and Artifacts Found with XP Deus at "Searched-Out" Site
It is NOT recommended to use the Iron Volume set at 0 during searching for "hot" coin spots at sites of former settlements because any "nail cluster" - a potential underground "repository" of masked coins, can be easily passed up if not audio indicated. Same goes for field reconnaissance - searching for settlement spots in vast farm fields. Some sound of iron should always be in the background during such recon searches.
The Iron Volume feature will be useless if you utilize All Metal mode (all metals are accepted) of Conventional Discrimination or set the first tonal zone's upper breakpoint (Threshold 1) within a range 0-2.
TONE Feature (in Program #10 of v3.0 and subsequent versions)
NOTE: A factory pre-set program #10 - GOLD FIELD, available only in the v3.0 and subsequent versions, utilizes a Tone function which allows to set the fundamental frequency of the audio pitch signal.
The Tone function allows an operator to adjust an audio frequency (pitch) of the iron tone in a range from 150 to 603 Hz according to the operator's liking or to the requirements of the "Gold Field" search program (page 12 of the v3.0 user manual).