Metal Detector Coils: Sizes, Types & Best Picks (2026)

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The fastest way to waste money on a metal detector is to bolt on the wrong search coil—especially because the depth a manufacturer quotes in an air test almost never survives real soil. Coil choice changes everything: separation in trash, coverage on open ground, sensitivity to small targets, and overall swing weight.

Most compatibility mistakes come from the assumption that any coil fits any detector. They don't. The Minelab Equinox accepts only OEM EQX coils and Minelab-approved Coiltek NOX coils, while Garrett splits its lineup into three mutually incompatible coil families: ACE, AT, and Apex/Vortex. Buy the wrong one and it won't even plug in.

This guide breaks down coil size, coil configuration, and the model-by-model compatibility traps for Minelab Equinox, Garrett ACE/AT, Nokta Legend, and Minelab Vanquish. It also covers the Equinox coil-ear failure that hits far more users than any marketing page mentions.

It's for detectorists who already own one of these machines and want a specific, terrain-matched upgrade—not a generic explanation of how coils work.

Coil size	Best use	Main trade-off
4–6"	High-trash parks, tight spots, small targets	Less coverage; shorter detection range on large objects
8–11"	All-round coin, jewelry, and relic hunting	Balanced but not specialized
12–15"+	Open fields, beaches, large deep targets	Heavier; reduced sensitivity to small targets

How Metal Detector Coils Work

A search coil is a transmit winding and a receive winding in one housing. The transmit winding generates an electromagnetic field; when a conductive or magnetic target enters the field, it disturbs the return signal, and the detector interprets phase shift, amplitude, and stability to assign a target ID. The way that signal becomes a number is covered in depth in Metal Detector Discrimination & Target ID Explained.

Frequency behavior matters because it determines whether a coil is universal or model-specific. On simultaneous multi-frequency machines—Minelab Equinox Multi-IQ, Nokta Legend, Vanquish Multi-IQ—the coil is frequency-agnostic: the control box sets the frequencies, not the coil. On single-frequency units such as the Garrett ACE 300 at 8 kHz, ACE 400 at 10 kHz, or AT Pro at 15 kHz, the control box determines frequency. This distinction is why the exact same EQX 11 coil works on an Equinox 600 and an X-Terra Pro without any retune.

Coil Configurations Explained

Configuration	How it works	Strengths	Typical use
Double-D (DD)	Two D-shaped overlapping windings	Stable in mineralized ground, better target separation, less EMI	Modern standard; nearly all Equinox, AT, and Legend coils
Concentric	Nested circular transmit and receive windings	Slightly deeper on coins in mild soil, precise pinpointing	Entry-level and legacy ACE-style detectors; rare on flagships
Mono	Single winding used on pulse induction machines	Deep on large gold nuggets, largely immune to mineralization	PI gold prospecting
Elliptical	DD in an elongated footprint	Narrow separation with longer coverage	Trashy sites, shallow water, tight quarters

Concentric coils still have old-school defenders who argue a same-size concentric goes deeper on coin-sized targets in mild ground. The modern consensus favors DD because it holds stable target IDs in mineralized soil and separates iron-adjacent targets far better. That's why Minelab, Nokta, and the Garrett AT series all ship DD coils on their current flagships.

Coil Sizes and the Depth Myth

Size breaks into three practical bands. Small coils from 4" to 6" separate dense iron and let you work scrubby or rocky ground where a big coil won't fit. Medium coils from 8" to 11" balance coverage, depth, and sensitivity and are the right starting point for most hunting. Large coils from 12" to 18" cover more ground per swing and reach deeper on large objects, but they lose sensitivity to small targets and make pinpointing less precise.

The biggest myth to reject is that a bigger coil automatically finds coins deeper. Field testing consistently shows that large coils do not produce meaningful extra depth on coin-sized targets in real soil. A 15" or 18" coil helps reach deep, large objects and lets you cover a field faster; it does not turn a 6" dime signal into a 14" dime signal. At the same time, smaller coils often improve recovery of small targets sitting next to iron because their narrower detection field separates adjacent objects.

Air-test numbers inflate all of this. Manufacturer depth claims shrink significantly in mineralized ground—up to 50% in severe iron or black sand. If the target dirt is hot, real-world depth will fall far short of the spec-sheet figure.

Brand-by-Brand Compatibility & Best Picks

Search coils are tuned to the electronics and frequency of one detector family. The Equinox uses only OEM EQX and Minelab-approved Coiltek NOX coils—no NEL, Detech, or CORS alternative exists because of Minelab's chipped coil design. The XP Deus and Deus II use fully wireless coils with onboard electronics and have no aftermarket options. Garrett's ACE Apex and Vortex lines use different connectors from older ACE and AT models, so coils don't cross over. Always confirm the connector type before buying.

Minelab Equinox: EQX and Coiltek NOX

Before choosing an Equinox coil, understand the platform's biggest structural weakness. The plastic coil ears are the most common failure point, and over-tightening the coil bolt is the primary cause cited by Minelab repair technicians. Thin ear walls and worn shaft washers make matters worse. Set the bolt finger-tight plus roughly a quarter turn, replace worn washers, and consider a 3D-printed stiffener before the ears snap. Minelab thickened the ear walls on later 700/900-series production, and the repair network generally honors warranty replacements for this issue.

Top all-round baseline: Minelab EQX 11 Double-D Smart Coil

Specs: 11" round Double-D; fits Equinox 600, 700, 800, 900 and X-Terra Pro/Elite; submersible to 3 m on 600/800 and 5 m on 700/900.
Positioning: mid; the stock coil on every Equinox, and the best balanced do-everything coil in the system.
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Pros: best blend of depth, coverage, and sensitivity; included with new machines; fully waterproof.
Cons: not specialized for trash or open-field coverage; vulnerable plastic ears.
Verdict: If you need a replacement or a first spare for general hunting, this is still the safest all-rounder.
Perfect for: general park, field, and dry-sand beach hunting.

Best trash and iron pick: Minelab EQX 06 6" Double-D Smart Coil

Specs: 6" round Double-D; weighs 300 g with skidplate; fits Equinox 600, 700, 800, 900 and X-Terra Pro/Elite; waterproof to detector rating.
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Pros: excellent separation in iron-infested sites; punches above its size; light enough for all-day use.
Cons: less ground coverage; not the right tool for open fields.
Verdict: The go-to small coil for old parks, cellar holes, and trash-heavy lots.
Perfect for: high-trash parks, old homesteads, tight terrain.

Best overall Equinox upgrade: Coiltek 10x5 NOX Elliptical DD

Specs: 10"x5" elliptical Double-D; weighs 426 g; fits Equinox 600, 700, 800, 900 and X-Terra Pro/Elite; Minelab-approved plug-and-play; submersible to 3 m on 600/800 and 16.4 ft on 700/900/X-Terra Pro; 2-year warranty.
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Pros: superior separation and pinpointing; roughly 1" deeper than the EQX 06; the only aftermarket coil brand Minelab sanctions for Equinox.
Cons: costs more than the OEM 6"; not designed for wide-open coverage.
Verdict: Frequently called the best single Equinox upgrade period. If you hunt trash or shallow water, this is the pick.
Perfect for: trashy ground, riverbanks, shallow water, target separation next to iron.

Deep open-field pick: Minelab EQX 15 15"x12" Double-D Smart Coil

Specs: 15"x12" elliptical Double-D; weighs 660 g with skidplate; fits Equinox 600, 700, 800, 900 and X-Terra Pro; submersible to 10 ft on 600/800 and 16 ft on 700/900.
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Pros: deepest OEM Equinox coil; roughly 2" more depth than the 11" in good ground; covers more ground per swing.
Cons: extra weight; coil-ear breakage more common after heavy beach use; reduced small-target sensitivity.
Verdict: For low-trash pasture, beaches, and deep large targets—not for coin-shooting a park.
Perfect for: open fields, low-trash beaches, depth hunting large objects.

For maximum coverage on Equinox, Coiltek also offers 15" and 18" NOX round coils. The 18" covers 60% more area per swing than the stock 11" and is rated 30% deeper than the EQX 15 on medium and large objects—but it's a niche depth specialist, too heavy for everyday hunting.

Garrett ACE and AT: stock and aftermarket

Garrett has three mutually incompatible coil families. ACE 200/250/300/350/400 coils interchange with each other, but they do not fit the ACE Apex, which uses a Multi-Flex connector. Vortex coils use yet another proprietary waterproof connector. The 5"x8" and 6"x11" Viper also exist in separate ACE, AT, Apex, and Vortex versions—buy the exact variant marked for your detector family.

Budget all-rounder: Garrett 8.5"x11" DD PROformance (ACE Series)

Specs: 8.5"x11" semi-elliptical Double-D; about 15.2 oz; fits ACE 200, 250, 300, 350, 400; fully waterproof coil; 3-year Garrett warranty; made in the USA.
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Pros: strong general-purpose coverage; stock on the ACE 400; all ACE coils interchange regardless of frequency.
Cons: does not fit ACE Apex; control box on ACE machines is not submersible, only the coil.
Verdict: The stock coil is all most coin-shooters need on an ACE detector.
Perfect for: beginner ACE users on parks and dry land.

Best trash pickup for ACE and AT: Garrett 5"x8" DD PROformance

Specs: 5"x8" semi-elliptical Double-D; 11.2 oz; ACE version fits ACE 200/250/300/350/400; separate AT version for AT Pro/Gold/Max; waterproof.
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Pros: stays stable in trash and mineralized ground; works well on salt beaches; fits tight spaces.
Cons: less ground coverage; must purchase the correct ACE or AT variant.
Verdict: Many detectorists keep this on as their main coil, and Garrett support itself recommends it for trashy sites.
Perfect for: parks, trashy lots, salt-sand beach hunting.

Best AT-series iron upgrade: Garrett 6"x11" DD Viper

Specs: 6"x11" Double-D; about 1 lb; AT version fits AT Pro, AT Gold, AT Max; fully waterproof/submersible; 3-year warranty.
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Pros: goes as deep or deeper than the stock 8.5"x11" with less EMI and better separation in iron.
Cons: not compatible with Apex or Vortex; heavier than a small coil.
Verdict: The best AT-series upgrade for relic and iron-heavy ground.
Perfect for: relic sites, iron-infested fields, AT Pro/Max owners.

Aftermarket depth option: Detech 13" Ultimate DD (Garrett AT)

Specs: 13" Double-D; waterproof; coil cover included; fits Garrett AT Pro, AT Gold, AT Max.
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Pros: more stable operation, better ground balance, and more accurate target ID than the standard DD; one of the few third-party AT options.
Cons: makes lighter detectors nose-heavy; the extra depth is only about 1.5–2" and may not justify the cost for beginners.
Verdict: Only worth it if you hunt open ground and want every last inch on an AT machine.
Perfect for: AT users on open land with low trash.

Nokta Legend: LG24 and LG30

Nokta Legend coils are not cross-compatible with Simplex detectors, and older Simplex+ SP-series coils don't fit the newer Simplex Lite/BT/Ultra SX-series because the operating frequency changed from 12 kHz to 15 kHz. On the Legend itself, the LG-series coils are the upgrade path.

Best all-round Legend coil: Nokta LG30 12"x9" DD

Specs: 12"x9" semi-elliptical Double-D; weighs 499 g; fits Nokta The Legend and Legend 2; waterproof/submersible; includes coil cover and hardware; stock on Legend Pro Pack.
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Pros: lighter than the stock 11" LG28; slightly better separation plus more coverage.
Cons: only fits Legend family; not a Simplex coil.
Verdict: The best single general-purpose Legend coil for fields and beaches.
Perfect for: Legend owners hunting parks, fields, and dry beach.

Best trash and beach-jewelry Legend coil: Nokta LG24 9.5"x6" DD

Specs: 9.5"x6" elliptical Double-D; weighs 385 g; fits Nokta The Legend and Legend 2; waterproof; includes coil cover and hardware.
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Pros: nearly identical weight to the 6" LG15; great in trash and tight spaces; excellent for all-day swinging.
Cons: less coverage than the LG30.
Verdict: The top Legend coil when separation matters more than coverage.
Perfect for: trashy parks, tight terrain, beach jewelry hunting.

Minelab Vanquish: V12 and the V-series

Vanquish owners need to know there are two separate coil families. The legacy Vanquish 340, 440, 540, and 540 Pro-Pack use the V8, V10, and V12 coils. The X-Terra Pro/Elite and Vanquish V60 use the V*X-series (V8X, V10X, V12X). They are not interchangeable.

Best Vanquish beach coil: Minelab V12 12"x9" DD

Specs: 12"x9" elliptical Double-D; fits Vanquish 340, 440, 540, 540 Pro-Pack; coil waterproof though the Vanquish control box is not submersible; stock on Vanquish 540.
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Pros: best beach depth in the V-series; solid medium coverage.
Cons: only the coil is waterproof; control pod remains water-resistant, not submersible.
Verdict: The deepest V-series option for beach work; V10 is the best all-rounder, V8 for trash.
Perfect for: Vanquish owners hunting dry and wet sand.

The XP Deus and Deus II are a separate case. Their coils, remote, and headphones are fully wireless, and every XP coil contains its own electronics. There are no aftermarket coils for the platform, so the choice is limited to XP's own 9", 11", 13x11", and HF elliptical coils. That restriction is part of the design, and it's covered in the XP Deus Review.

Which Coil Should You Choose?

The beginner consensus across forums is clear: learn the stock coil first. Most detectorists need only two or three coils total—add a small coil for trash and a large coil for open depth, then stop.

Hunting scenario	Recommended coil
Trashy park, old home site, iron-infested ground	5"x8" on ACE/AT, 6" on Equinox, Coiltek 10x5 NOX, or Nokta LG24
General coin, jewelry, and relic hunting	Stock 11" DD on Equinox, 8.5"x11" on ACE, LG30 on Legend
Open field, pasture, low-trash beach	13–15" DD on AT or Equinox, V12 on Vanquish
Tight spaces, shallow water, separation	Small elliptical DD such as 10x5 NOX or LG24
Gold prospecting	PI mono coil or high-frequency DD, depending on machine

If gold jewelry is the target, coil recovery speed and separation matter more than depth. Pairing a small coil with a submersible machine is the setup that actually pays off on wet sand, as covered in Best Metal Detectors for Jewelry Hunting.

Frequently Asked Questions

Q: What coil upgrade should I buy first?

Don't buy one yet. Learn the stock coil until you can identify targets by audio and handle ground balance confidently. After that, the most useful upgrade for most people is a small DD coil for trash separation, followed by a large coil if you regularly hunt open fields.

Q: Do larger coils find coins deeper?

No. Larger coils help on large or deep targets and cover more ground per swing, but they do not produce meaningful extra depth on coin-sized objects in real soil. They also lose sensitivity to small targets and make pinpointing less precise.

Q: Can I put a Coiltek, Detech, or NEL coil on my Minelab Equinox?

Only Coiltek NOX coils are Minelab-approved for Equinox. Because of Minelab's chipped coil design, there are no NEL, Detech, or CORS coils for the Equinox platform. Detech makes coils for Garrett ACE and AT platforms, but compatibility ends there.

Q: Are Garrett ACE coils compatible with the ACE Apex?

No. The ACE Apex uses a Multi-Flex connector, and Vortex uses a different waterproof connector. ACE 200/250/300/350/400 coils interchange among themselves, but they do not fit the Apex or Vortex. Always match the exact coil variant to your detector family.

Q: How do I prevent coil ear breakage on my Equinox?

Set the coil bolt finger-tight plus about a quarter turn—over-tightening is the main cause. Replace worn shaft washers and use a 3D-printed stiffener as insurance. Later-production Equinox models have thicker ears, and Minelab generally covers genuine fracture under warranty.

Q: What is the difference between DD and concentric coils?

A DD uses two D-shaped overlapping windings and excels in mineralized ground, separation, and EMI immunity. A concentric uses nested circular windings and can go slightly deeper on coins in mild soil with precise pinpointing, but it struggles in mineralization. Current flagships almost all ship DD coils.

Conclusion

Coil choice is less about "bigger is better" and more about matching the coil footprint to the dirt you actually hunt. For most detectorists, the smart setup is a stock all-round DD plus one small DD for trash-heavy sites. Skip huge coils unless you specifically chase large, deep targets on open ground.

The two non-negotiable facts are compatibility and mechanical care. The Equinox is a closed coil system with only one sanctioned aftermarket brand, while Garrett's ACE, AT, Apex, and Vortex coils are not interchangeable despite looking similar. On any Equinox, torque discipline and cheap coil-ear stiffeners prevent the most common field failure. For more on maintaining the rest of the machine, see Metal Detector Repair: Common Issues & When to Fix vs Replace. If you want to understand how coil signals become target IDs before you commit to a purchase, Metal Detector Discrimination & Target ID Explained adds the other half of the skill.

If you hunt an Equinox in trash or shallow water, the Coiltek 10x5 NOX is the single upgrade most likely to save you dig time. → Check the current price on Amazon

Metal Detector Coils Guide: Sizes, Types & Best Picks (2026)