Garrett AT Max, Manual

14 Garrett Metal Detectors

AT Max

™ 

15

All Metal Mode Audio Characteristics

While in the ALL METAL Mode, the 

AT Max

 will respond to the 

entire range of conductive and magnetic properties encountered, 
including ground responses. The user is continuously hearing what 
the searchcoil is "seeing" in the ground. Therefore, it is essential to 
be properly ground balanced while operating in the ALL METAL 
Mode. Naturally occurring minerals in the soil must be canceled 
out during the ground balance procedure in order to detect only 
the signals from metal objects.
  The ALL METAL Mode provides target information, including 
a Target ID pixel on the upper scale, Digital Target ID, and depth 
reading. The 

AT Max

 thus allows the operator to remain in the ALL 

METAL Mode at all times, in contrast to some detectors which 
require the operator to switch to a Discrimination mode to obtain 
Target ID. Be aware that some deeper targets (faint audible signals) 
may exceed the reach of Target ID.
  Because the ALL METAL Mode permits no discrimination, the 
detector will give an audible signal to indicate every piece of 
metal it scans over. Target responses will normally be heard as a 
proportional Medium Tone. However, the 

AT Max

 is a unique All 

Metal detector in that its Iron Discrimination and Iron Audio™ 
features can be used to hear if detected targets are ferrous, as 
indicated by a low tone. Iron Discrimination levels can only be 
adjusted in the ALL METAL Mode if the Iron Audio feature is on;  

note, these changes will not be retained when the detector is 
switched off. 

(See Iron Audio section, pages 28–31.)

  Gold prospectors and many relic hunters rely primarily on 
their ears to discern good target signals. These desired signals 
are presented as clean, repeatable responses that override the 
background audio.

Discrimination Mode Audio Characteristics

The 

AT Max

 includes three Discrimination Modes: Custom, Coins, 

and Zero. These modes are used to eliminate trash metal items 
(e.g. foil, pull-tabs, nails) from detection and provide more Tone 
ID information that the ALL METAL Mode. Discrimination filters 
are introduced in these three modes, which can make them less 
sensitive to small and deep targets than the ALL METAL MODE.
  In its Discrimination Modes, the 

AT Max

's Tone Roll Audio 

provides the user with more target information to help identify 
targets, particularly flat iron objects such as bottle caps and 
washers, especially with Iron Audio switched on. Tone Roll Audio 
provides a variance of target tones as the searchcoil approaches 
and passes over the target. These varying tones of audio provide 
better overall target information and identification.