Garrett ACE 400 Review (May 2024)

In this review we’ll look at the Garrett ACE 400 metal detector.
We’ve compared value for money, features, ease of use and detecting ability
to give you our top recommendations.

Garrett ACE 400 Overview

  • Best in Garrett's ACE series
  • 5 pre-set search modes
  • Waterproof search coil

In-Depth Garrett ACE 400 Review

Garrett ACE 400 Metal Detector

  • Best in Garrett's ACE series
  • 5 pre-set search modes
  • Waterproof search coil

Garrett ACE 400 Metal Detector Review

Garrett’s Ace 400 is the top metal detector in the ACE series. It replaced the popular ACE 350 and improved it with extra features.

This is an entry-level machine that’s pushing into the mid-range. If you’re looking to upgrade your beginner model but not ready to spend $1000s, the ACE 400 is worth serious consideration especially as it’s usually available for $300-400.

Features and Benefits of the Garrett ACE 400


Garrett’s range of ACE metal detectors have simple control boxes that all look very similar. If you’ve used an ACE before then it’ll take no time to understand the 400’s controls.

It’s all labelled and the display is clear – although in bright sunlight you’ll be squinting. The main buttons are mode, discrimination, and sensitivity and they work on a plus and minus toggle. There are iron audio and frequency adjust buttons too.

Most of the control box is taken up with the Target ID which shows you what conductivity metal you’ve found and the depth of your target.

It’s simple stuff.


The ACE 400 is a VLF metal detector with a frequency of 10khz. It’s more likely to pick up smaller targets than others in the ACE range.

It has frequency adjust to help soothe the squealing when you’re near power lines or other detectorists.


The ACE 400 has 12 notch discrimination modes and five pre-set search modes which are:

  • Zero disc that hunts out all metal with no discrimination.
  • Jewelry mode for metals commonly made into jewelry,
  • Relic mode which eliminates iron and is more likely to pick up lead and bronze.
  • Coin mode which hones in on common coins metals.
  • Custom mode so you can choose a mixture of the above or your own special recipe. The ACE 400 saves your custom mode so it’s ready to go next time.

Garret has added digital target ID with numerical information to the ACE 400 which is a great move as the 350 didn’t have that level of tech.

Target ID works on a 0-99 scale. Iron registers low whereas coins register high and the vertical graph shows you how deeply the target is buried. You’ll know pretty much what’s down there before you dig.

There’s also a built-in pinpoint function which is always handy.


The search coil is waterproof so you can search on river edges, but the control box is not waterproof.

Beware rain and setting your machine down on wet grass.


When you hit a target the ACE 400 will give one of three tones. What pitch tone you get depends on the conductivity of the metal.

A coin will ring out the high bell while low conductivity will sound out lower. It’s pretty easy to figure out. You can adjust the newly upgraded ‘pulse width modulation’ system to your audio preference.

I mentioned at the start there was an iron audio button on the control box. This is an upgrade on the 350 and allows you to hear certain iron targets depending on your discrimination.

For example, a nail will sound out a few lower tones and a bottle cap will shout out high-low-high. Iron audio means you won’t miss anything important while filtering the trash.

Ground Balance

There is ground balancing but its pre-set and you can’t change it.

This is one of the ways Garrett keeps the price down. It’s also why the ACE range is primarily aimed at beginners.

Experienced detectorists use manual ground balancing function to enhance their search but beginners often struggle with it. Pre-set ground balancing can really help you out in the early days.

Where Is Best To Use The Garrett ACE 400?

This is a great machine for the majority of soils. You can use it on dry sand but it won’t like saltwater, wet sand and highly mineralized soils.

The ACE 400 will squeal and drive you nuts in these conditions. To be fair, all lower price bracket VLF machines do this, it’s not a fault with the ACE 400.

What Will The ACE 400 Find?

Up to eight inches depth on dry sand and ‘normal’ soils you’ll find jewelry, relics, coins, and trash.

You won’t have much luck finding gold nuggets because the pre-set ground balancing won’t cope well in mineralized soil where wild gold is found.

Use the modes to narrow down your specific search, you could always strike lucky with a gold ring.


The ACE 400 comes with an 8.5 x 11 inch DD PROformance search coil. It’s a great starting place with plenty of sensitivity.

If you want to up your game the ACE 400 is interchangeable with other Garret coils such as:

  • Super Sniper 4.5 search coil for focusing on really small areas.
  • 5 x 8 DD coil for small spots
  • 9 x 12 inch PROformance coil to cover more ground

How The ACE 400 Compares to Other Garrett Detectors?

The 400 is the top of Garrett’s ACE range, above the ACE 200 and ACE 300. Its aimed at beginner to mid-level and occasional weekend detectorists.

It’s got enough features to keep you happy including digital target ID, search modes, and iron audio but not so much tech it’s become unaffordable.

Check my detailed comparison of ACE 300 vs ACE 400 here.

Drawbacks include the pre-set ground balance – you’d have to upgrade to an ATX or GTI 2500 for kind of tech, and it’s not submersible unlike the AT Pro which is submersible up to 10ft.

For a thorough comparison of ACE 400 vs AT Pro see here.

The ACE 400 is an upgrade that’s replaced the ACE 350 and it’s done a good job of keeping the best bits but adding the much-needed extras to cope with iron trash.

Bonus: Fisher’s F44 is also a well-priced mid-range metal detector. For a detailed comparison of the ACE 400 vs the F44, check out this post.

Other Important Bits

It’s easy to get bogged down in specifics when you’re looking for the best metal detector, but don’t forget these basic bits of information.

Weight and Length

The ACE has an adjustable stem ranging from 40 inches to 53 inches with cam locks and it weighs only 2.9 lbs. You won’t get ‘swing ache’ from this machine


It’s powered by four AA batteries and there’s a continuous battery-level indicator.


There’s a two-year warranty on the ACE 400.

What Are The Cons of Garrett ACE 400?

This is a great machine for the price and one of the best metal detectors for beginners or those with some experience.

Cons are the pre-set ground balancing – but then this isn’t an issue for a beginner, and iron audio that bumps up the price can drive you insane targeting trash. For that reason, mine is usually off.

The three-part stem is sturdy but when the larger search coil is attached it can feel a little loose at the joins. No biggie – but worth noting.


I’d recommend Garrett’s Ace 400 model for beginners willing to invest a little more cash and anyone wanting to upgrade from a basic machine and doesn’t want to spend $1000s.

You’ll get great results with any ACE but the 400 tops them all when it comes to avoiding iron.

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