Garrett ACE series
Garrett ACE 400 Settings by Site Type, Including Iron Audio
Quick answer
Set the Garrett ACE 400 by ground rather than by menu: raise sensitivity to the point of chatter and back off two steps, keep discrimination minimal, leave Iron Audio switched on so ferrous targets stay audible, and shift the adjustable frequency rather than dropping sensitivity when the noise is electrical.
The ACE 400 gives you four published controls that matter in the field: sensitivity, discrimination, the adjustable frequency, and Iron Audio. That is a short list by modern standards, and it is an advantage. Fewer settings means fewer ways to be quietly wrong for an entire season without knowing it.
What follows is a starting point per site type. It is not a preset sheet, because presets are a fiction when soil mineralisation varies within a single field. Change one thing at a time and give each change a full session.
Top pick
Garrett ACE 400
Iron Audio plus a higher published operating frequency than the 300 makes this the ACE to own if your ground is full of nails.
Price was accurate when this page was compiled and changes often.
What order should you set the controls in?
Sensitivity, then frequency, then Iron Audio, then discrimination. Sensitivity establishes what the ground will carry. Frequency deals with electrical noise that sensitivity should never be used to cure. Iron Audio goes on and stays on. Discrimination comes last and should be the smallest number you can live with.
The most common self-inflicted wound on an ACE is cutting sensitivity to silence noise that was electrical in origin. If the machine chatters with the coil raised and still in the air, away from the ground, the problem is interference and the adjustable frequency is the fix. If it only chatters on the ground, the problem is mineralisation and sensitivity is the fix.
What settings suit each site type?
Sensitivity is expressed relative to the chatter ceiling you find on arrival, because that ceiling belongs to the ground and not to the detector.
The iron-heavy old house site is the one place where the ACE 400 earns its premium over the 300, because Iron Audio turns silent rejected ferrous targets back into information.
| Site type | Sensitivity | Discrimination | Iron Audio | Sweep and coil |
|---|---|---|---|---|
| Mown town park | Two steps below chatter | Small iron only | On | Stock coil, slow, half-width overlap |
| Old house site, heavy iron | Moderate, iron forces it down | Minimal or none | On, and listen to it | Slowest sweep, smallest coil you own |
| Open pasture, permission | Ceiling for the ground | Minimal | On | Stock coil, long lanes with the furrows |
| Ploughed field | Ceiling for the ground | None | On | Work along furrows, regrid after rain |
| Dry beach above the tide line | High | Small iron only | On | Grid the towel line, not the whole beach |
| Wet salt sand | Low, roughly half of inland | Small iron only | On | Short sweeps; a single-frequency machine is out of its depth here |
| Freshwater bank and stream | High | Small iron only | On | Coil may be wet, control box must not be |
| School field, sports ground | High | Small iron only | On | Expect heavy foil and tab trash |
Starting points expressed relative to your own noise ceiling, not manufacturer settings. The ACE 400 owner's manual is the authority on what each control does on your firmware.
How do you work an iron-infested site without going mad?
Halve the sweep speed, halve the coil width, and double the overlap. Iron masks non-ferrous targets by dominating the coil's field, and the only cures are physical: less ground under the coil at any one moment, and more passes. Iron Audio then tells you which of the surviving signals have ferrous company.
Accept the arithmetic. A site like this yields perhaps a fifth of the targets per hour that clean pasture does, and most of what you dig will be rubbish. That is why it is still there to be found. Budget your time honestly with the dig time budget before you commit a day to it, and read the ACE 300 settings page if you are running the cheaper machine on the same ground.
What kit supports this way of working?
Slow sweeps and heavy trash mean more holes per hour, which makes recovery gear the limiting factor rather than the detector.
Garrett ACE 400
$357.99Iron Audio and a 0 to 99 target ID at $357.99.
Best for: iron-heavy sites and small low-conductive targets
Check price on Amazon
Garrett Pro-Pointer AT
$109.99Submersible to twenty feet with a fast retune that tunes out mineralised ground in the hole.
Best for: anyone digging in trash
Check price on Amazon
Garrett Camo Digger's Pouch
$19.99Keeps the trash you are now digging separate from the finds you came for.
Best for: a first pouch
Check price on AmazonHow we chose
We did not test these machines in person and we publish no find claims. Picks are researched from manufacturer specifications and owner manuals, published listing features, waterproof ratings and warranty terms, and the recurring themes in verified owner reviews. We favour the established detector brands because coils, shafts and control boxes have to stay available years after a model is discontinued, and we place every pick in the tier where its price and capability honestly belong.
Sources
- Garrett ACE 400 owner's manual
- Garrett ACE 400 published feature listing, including Iron Audio and adjustable frequency
- Garrett ACE series specification sheet
Frequently asked questions
Should Iron Audio stay on all the time?
For at least your first season, yes. It costs you nothing but noise, and it tells you what the discrimination circuit is silently discarding. Once you know your sites well you may switch it off on clean pasture where iron is rare and the grunting is simply tiring. On an old house site or a farmyard it should never be off.
What discrimination should I run on an ACE 400 in a park?
Reject small iron and nothing else. Parks are full of foil, tabs and screw caps, and every one of those sits in or near the band where gold jewellery also reads. Rejecting that band guarantees you never find a ring. Dig the mid range, keep a trash pouch, and let the volume of rubbish be the price of the occasional good find.
Can the ACE 400 handle a saltwater beach?
Above the tide line, yes. On wet salt sand it is out of its element, because a single-frequency machine reads conductive salt water as ground noise and you have to give away sensitivity to quieten it. Garrett's own multi-frequency answer in this family is the ACE Apex with its Multi-Salt setting. No adjustment to an ACE 400 substitutes for that.
Does the adjustable frequency change depth?
Not meaningfully. Garrett describes the control as a way to minimise interference from electrical sources or from other detectors in crowded areas, and that is the job it does. The depth benefit is indirect: if shifting frequency lets you run two or three steps more sensitivity than you otherwise could, you gain depth from the sensitivity, not from the frequency itself.
How do I stop losing permissions?
Cut small plugs, replace the turf so the seam disappears, and carry out every piece of metal you dig including the rubbish. Ask before you bring anybody with you. Tell the owner what you found, even when it is nothing. Most lost permissions are lost over holes and gates, not over finds, and a reputation for tidy ground outlasts any single site.
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.