Metal detector performance depends heavily on discrimination settings and ground conditions — factors that matter as much as, or more than, the detector's raw sensitivity or price tier.
Discrimination lets a detector ignore certain metals
Discrimination settings let a detector distinguish between different metal types based on their electrical conductivity, allowing junk metal like pull tabs, foil, and nails to be filtered out rather than triggering a signal for every piece of metal encountered. Higher discrimination reduces false signals from junk but also risks filtering out genuinely valuable finds with similar conductivity signatures to junk metal — a real tradeoff, not a setting to simply max out for the "best" results. Many detectorists adjust discrimination based on the specific site and what they're looking for, rather than using one fixed setting for every search.
Ground mineralization affects performance more than most beginners expect
Soil with high mineral content — common in certain regions and soil types — can interfere with a detector's signal and cause false readings or reduced depth performance, sometimes significantly, regardless of how capable the detector itself is. Detectors with ground balance features, allowing manual or automatic adjustment to compensate for a specific location's mineral content, perform meaningfully better in challenging, highly mineralized soil than detectors without this capability — worth prioritizing for anyone detecting in a region known for mineral-rich soil rather than assuming any detector performs consistently across all ground conditions.
Frequency affects sensitivity to different target types and sizes
Lower frequency detectors generally perform better for larger, deeper targets and are less affected by ground mineralization. Higher frequency detectors are generally more sensitive to smaller targets and low-conductivity metals like gold, but with somewhat reduced depth capability. Multi-frequency detectors, which operate across a range of frequencies simultaneously, aim to capture benefits of both, generally at a higher price point than single-frequency detectors.
Coil size trades depth and sensitivity against precision
Larger search coils generally detect targets at greater depth and cover more ground per sweep, but are less precise at pinpointing a target's exact location and can struggle in areas with a lot of nearby junk metal, since a wider coil picks up more targets in a given area at once, making it harder to isolate one signal. Smaller coils offer more precise target location and perform better in trashy, junk-heavy areas or tight spaces, at the cost of some depth and ground coverage speed.
The one thing people forget
Check local laws and obtain permission before detecting on any land, including public parks, beaches, and especially historical or protected sites, which often have specific restrictions or outright prohibitions on metal detecting and artifact removal. This isn't just courtesy — detecting on protected historical or archaeological sites without authorization can carry real legal consequences in many places, regardless of how accessible or unmarked the location might appear.