Garrett AT Max
Garrett AT Max Settings by Site Type: Park, Field, Beach and Relic
Quick answer
Start the Garrett AT Max around 70 to 80 percent sensitivity, ground balanced on site, with Iron Audio on in trash. Use True All Metal for maximum depth on clean ground, cut sensitivity to 50 to 65 percent on wet salt sand, and run the smaller coil rather than more sensitivity in parks.
The Garrett AT Max is the AT platform with Z-Lynk wireless built in, a higher operating frequency and a backlit display, and it is set up much the same way as an AT Pro. The differences that matter in the field are True All Metal mode, which Garrett describes as detecting all metal types with the greatest possible depth and sensitivity, and the extra liveliness that 13.6 kHz gives on small low conductive targets.
These are starting points to tune in your first ten minutes on site. The honest limit of a single frequency machine in salt water applies here exactly as it does to the AT Pro, and it is stated below rather than glossed over.
Top pick
Garrett AT Max
Z-Lynk wireless with MS-3 headphones included, True All Metal mode and a backlit display for low light, waterproof to 10 feet.
Price was accurate when this page was compiled and changes often.
On this page
What are the starting AT Max settings for each site type?
Sensitivity is quoted as a share of the range. The correct figure is whatever your ground carries without chatter, so raise it until the machine complains and then step back two notches.
A Garrett AT Max runs roughly 70 to 80 percent sensitivity in a trashy park, 80 to 95 percent in clean field soil, and 50 to 65 percent on wet salt sand where a single frequency machine is working against the ground.
| Site | Mode | Sensitivity | Iron Audio | Ground balance | Note |
|---|---|---|---|---|---|
| Mown park, high trash | Coins or Custom | 70 to 80 percent | On | Automatic on site | Fit the 5 by 8 coil before raising sensitivity |
| Old yard, deep coins | Custom, low discrimination | 75 to 85 percent | Spot check | Automatic, recheck hourly | Depth beats separation here |
| Open field, low trash | True All Metal | 80 to 95 percent | Not applicable | Manual for best results | This is where True All Metal earns its keep |
| Dry beach sand | Coins or Custom | 70 to 85 percent | Off | Automatic | Behaves much like mild inland soil |
| Wet salt sand | Standard, reduced | 50 to 65 percent | Off | Manual, repeatedly | Expect falsing and lost depth on salt |
| Surf and shallow salt water | Standard, reduced | 40 to 60 percent | Off | Manual, constantly | Waterproof to 10 feet is not a salt mode |
| Fresh water, lake or river | Coins or Custom | 70 to 85 percent | Off | Automatic | Use the wired submersible headphones, not Z-Lynk |
| Relic site, heavy iron | Zero or Custom | 65 to 80 percent | On | Manual | Let the iron speak and judge by tone |
| Mineralised red clay | Standard or True All Metal | 55 to 70 percent | On | Manual, frequent rechecks | Ground noise limits you before depth does |
Starting points based on the AT Max owner's manual mode descriptions, Garrett's published True All Metal and Iron Audio descriptions, and common field practice. Soil varies by parcel, so tune every figure on site.
When should you use True All Metal on the AT Max?
Garrett describes True All Metal as the mode that detects all metal types with the greatest possible depth and sensitivity, and that is the honest way to think about it: it is the depth mode. Nothing is discriminated away, the audio is unfiltered, and in clean ground it will reach targets that the discriminating modes will not. The price is that you hear everything, including every nail and every hot rock.
Use it on open ground with low trash, on relic sites where you intend to assess targets yourself, and whenever you are chasing a deep signal you already suspect. Do not use it in a park full of bottle caps unless you enjoy digging them. It also demands careful ground balancing, because with no discrimination the ground signal has nowhere to hide.
Can the AT Max handle salt water?
The same honest answer as the rest of the line. Garrett publishes the AT Max as waterproof to 10 feet, which describes water ingress and nothing else. At 13.6 kHz it is a single frequency VLF machine, and salt water is a conductor that competes directly with target signals. On wet salt sand you will cut sensitivity, ground balance manually and often, and still accept falsing and reduced depth.
If the salt beach is your main ground, look at machines built for it: Garrett's own Garrett ACE Apex has a Multi-Salt option among its Multi-Flex choices, the Garrett Vortex VX9 adds simultaneous multi-frequency with a 16 foot submersion rating, and the Minelab Equinox 900 and Nokta The Legend Pro Pack both carry dedicated beach modes. The ratings across the AT line are laid out on the waterproof ratings page.
How should you set up the wireless audio?
Pair the included Garrett MS-3 Z-Lynk Wireless Headphones before you leave the house, not at the site with cold hands. Z-Lynk is Garrett's own low latency link rather than standard Bluetooth, which is what makes pinpointing by ear possible. Set the headphone volume so that a shallow coin is comfortable and a deep whisper is still audible, which usually means lower than people expect.
Carry a wired fallback. The Garrett MS-2 Headphones costs little, cannot run out of charge and lives in the bag for the day a battery dies. If the machine is going under water, the wired Garrett Submersible Headphones set is mandatory, because no wireless link works submerged. Anyone running a Z-Lynk pinpointer such as the Garrett Pro-Pointer AT Z-Lynk gets its audio in the same headphones, which is genuinely useful in wind.
What should you change when the ground gets noisy?
In order: rebalance to the ground, drop sensitivity two notches, slow the sweep, and only then start changing modes. Most people do this backwards and end up with a heavily discriminated machine that is quiet because it is deaf. If the noise is electrical interference rather than soil, the AT Max frequency adjustment is the tool for it, and moving twenty yards from a power line is often faster than any setting.
If noise persists in mineralised ground, the smaller coil is frequently the real fix, for the reasons set out on the coil compatibility chart. For readers still building a kit around the machine, the intermediate setup lists what actually gets used in a season.
Sources
- Garrett AT Max owner's manual, search modes, True All Metal and Iron Audio
- Garrett AT Max listing feature bullets, 13.6 kHz, Z-Lynk and the 10 foot waterproof rating
- Garrett ACE Apex and Vortex VX9 listing specifications for salt capable alternatives
Frequently asked questions
What sensitivity should I run on a Garrett AT Max?
Around 70 to 85 percent in most mild inland soil, lower in mineralised ground or on wet salt sand where 50 to 65 percent is often the stable ceiling. Raise it until the machine chatters, then come back two notches. Running maximum sensitivity in noisy ground costs you finds, because false signals mask the faint responses from genuinely deep targets.
Is True All Metal better than the discriminating modes?
It is deeper, not better. Garrett describes it as offering the greatest possible depth and sensitivity, and it achieves that by not filtering anything, so you hear every nail and hot rock as well. It suits clean open ground and deliberate target assessment on relic sites. In a park full of bottle caps it will simply slow you down. Choose it for the site, not as a default.
Can I use the AT Max wireless headphones underwater?
No. Wireless audio does not transmit through water, so a submerged AT Max needs the wired submersible headphones designed for the AT series. This catches people out at the waterline, because the machine itself is rated to 10 feet and everything seems fine until the coil goes under and the tones stop. Pack the wired set whenever water is part of the plan.
Should Iron Audio stay on all day on the AT Max?
On relic sites, usually yes, because the iron is part of the information. In a park it is better used as a check on suspicious signals, since constant iron grunting is tiring and after a couple of hours people stop listening to it properly. The useful habit is to switch it on when a high tone looks doubtful, particularly in bottle cap country.
Does the AT Max need manual ground balancing?
The automatic procedure is fine for most inland soil and takes seconds. Manual balancing gives finer control and matters in mineralised ground and in True All Metal, where there is no discrimination to hide a poor balance. Rebalance whenever the machine starts chattering, whenever moisture changes and whenever you move to visibly different ground rather than once at the start of the day.
Researched, not professional advice. This page is compiled from published specifications, manuals and owner-review consensus, not hands-on testing. Target ID numbers, depth figures and settings vary with soil chemistry, moisture, target size, depth, orientation and firmware version, so treat every figure here as a starting point and verify it against your own machine's manual and your own ground. As an Amazon Associate we earn from qualifying purchases.