What Makes a Good Coil? Here’s How the Right One Can Make All the Difference

What Makes a Good Coil? Here’s How the Right One Can Make All the Difference

When it comes to metal detecting, most people focus on the detector itself — but the coil you’re swinging is just as important. Whether you're chasing tiny nuggets in mineralised ground or covering open flats for deep gold, the right coil can completely change your results.

Not all coils are created equal. Shape, size, and coil type all impact how your detector performs — and understanding the difference can help you get more gold out of every swing.

Mono vs Double-D: What’s the Difference?

Mono Coils
Mono (monoloop) coils use the same winding to send and receive signals. They’re highly sensitive, punch deep, and are excellent in mild to moderately mineralised ground. Many experienced users prefer monos when chasing small gold in clean conditions.

Pros:

  • Maximum depth and sensitivity
  • Quieter in milder ground
  • Great for patch hunting

Cons:

  • Can be unstable in mineralised or salty ground
  • More prone to false signals in variable soils

Double-D (DD) Coils
DD coils use separate windings for transmitting and receiving. They offer more stable performance in mineralised or salty conditions, with a narrower detection line that helps with pinpointing and trash separation.

Pros:

  • Better ground handling in mineralised or salty soils
  • More stable and consistent
  • Ideal for general detecting

Cons:

  • Slightly less depth than a mono of the same size
  • Can miss the smallest gold in super clean ground

Coil Shape: Round vs Elliptical

Round coils generally offer more depth and sensitivity, ideal for pinpointing in open ground.
Elliptical coils provide better coverage and are easier to swing in tight scrub or rocky terrain.

Use this table as a quick guide:

Coil Size & Shape Best For
Small (5"–9") – Round or Elliptical Tiny gold, tight or trashy ground, lightweight setups
Medium (10"–14") – Round or Elliptical General purpose, balance of depth and coverage
Large (15”+) – Mostly Round Deep ground, big gold, open flats
Round Shape Best for depth, sensitivity, and pinpointing
Elliptical Shape Best for ground coverage, manoeuvrability

Our Go-To Brands

We only stock coils we trust — brands that consistently perform in Australian conditions:

  • Minelab – Factory-made, perfectly matched to their machines. Solid reliability and balance.
  • Coiltek – Aussie-made, field-tested, and innovative. The Goldhawk series, built for the GPX 6000, is a crowd favourite.
  • Nuggetfinder – Known for their light weight, excellent depth, and durable design. A top pick for patch hunters.

Choosing the Right Coil – Shape, Size & Job Comparison

Here’s a quick reference guide to help you decide:

Coil Type Shape Best For Pros Watch Out For
Small Coil (5"–9") Round or Elliptical Tiny gold, tight ground, trashy areas Super sensitive, easy pinpointing, lightweight Less depth and slower ground coverage
Medium Coil (10"–14") Round or Elliptical General all-round detecting Good balance of depth and sensitivity Choose shape based on terrain
Large Coil (15”+) Mostly Round Big gold, deep targets, open flat areas Excellent depth and ground coverage Heavier, less sensitive to small bits
Round Shape Round Depth and pinpointing Best depth, symmetrical sweep Harder in thick bush or rocky terrain
Elliptical Shape Elliptical Ground coverage and tight spaces Easier swing in scrub, covers more area Slightly less depth than round of same size

Real-World Example: Goldhawk Coils

The Coiltek Goldhawk series for the GPX 6000 gives you both round and elliptical options, letting you pick what suits your ground:

  • 9" Round – Great sensitivity and depth for small-medium gold

  • 10x5" Elliptical – Perfect for working scrubby gullies and tight terrain

  • 14x9" Elliptical – Ideal for covering ground and punching deeper on bigger gold

 

Final Thoughts

The right coil won’t just help you find more gold — it’ll make detecting smoother, more enjoyable, and more efficient. Whether you're tweaking your setup for tough ground, deep targets, or just want to cover more area, swapping out your coil could be the upgrade you didn’t know you needed.

Not sure which coil is right for you?
Come by the shop, give us a ring, or shoot us a message — we’re always happy to help.

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