01
Which one to pick
Each pick follows from the facts in the table below. Each button opens a listing for that model, and a bundle says what it adds.
Pick the ACE 300 if…
You can do without Iron Audio and headphones in the box, and want the lighter of the two, at 2.8 lb.
The listing title adds unnamed accessories and calls the coil waterproof. Garrett's pages give no water rating.
Pick the ACE 400 if…
You want the DD coil, the higher 10 kHz and headphones included in Garrett's box.
Sold as a bundle: the listing names a carry bag with the detector.
02
What sets them apart
The coil is the main split: concentric on the 300, Double-D on the 400. Garrett also raises the frequency, from 8 kHz to 10 kHz. On both, Garrett lists the frequency as adjustable.
The 400 adds Iron Audio. In Garrett's words, it lets you hear discriminated iron that is normally silenced, such as bottle caps or washers. The 300 has no Iron Audio. For headphones, our table, taken from Garrett's ACE chart, reads "Headphones included" for the 400 and "None included" for the 300.
Much else is shared. Both are single-frequency detectors with five search modes plus pinpoint, 8 levels of sensitivity and a target ID from 0 to 99. Both run on 4 x AA (included) and carry 3 years, limited parts and labor. The weights differ by a tenth of a pound, 2.8 lb against 2.9 lb.
Neither Garrett's product pages nor its ACE table give a water rating for either model. Keep both on dry ground. Garrett gives no battery life in hours for either one.
| Spec | DetectorACE 300 | BundleACE 400 |
|---|---|---|
| Frequencies | 8 kHz | 10 kHz |
| Weight | 2.8 lb1.27 kg | 2.9 lb1.32 kg |
| Coil | 7 x 10-inchPROformance, elliptical, concentric | 8.5 x 11-inchPROformance, elliptical, DD |
| Display | LCD | Not published |
| Technology | Single frequency | Single frequency |
| Waterproofing | Not published | Not published |
| Battery | 4 x AA (included) | 4 x AA (included) |
| Battery life | Not published | Not published |
| Search modes | 5 plus pinpoint search modes | 5 plus pinpoint search modes |
| Target ID | 0 to 99 | 0 to 99 |
| Warranty | 3 years, limited parts and labor | 3 years, limited parts and labor |
View on Amazon ACE 300 (opens in a new tab)Affiliate link | View on Amazon ACE 400 (opens in a new tab)Affiliate link |
Facts from Garrett's page for each model, read Oct. 16, 2026.
03
Questions
Answered from the makers' pages, read Oct. 16, 2026.
Four things. The 400 adds a DD coil, a higher frequency, Iron Audio and headphones in the box. The 300 keeps a concentric coil and weighs 0.1 lb less.
Garrett states no water rating for the ACE 400 or the ACE 300, so we treat both as dry-ground detectors.
Only the 400. Garrett's ACE chart marks headphones included for the 400 and not for the 300.
04