Metal Detector Settings: How to Choose Notch Width and Rejection

Start With a Narrow Notch

Begin with discrimination low enough to hear iron, then use notch rejection only for a narrow and familiar trash range. This preserves targets that overlap with pull tabs, foil, bottle caps, and small aluminum scraps.

Notch width is the span of Target ID values you choose to accept or reject. On a detector with a 0–99 ID scale, a narrow notch might cover IDs 27 through 30. On a detector that uses visual segments, one segment is the smallest practical starting point.

Rejection is the decision to mute that selected range. The difference between the controls matters:

• A narrow notch rejects one tightly defined ID range.
• A wide notch rejects several nearby target types at once.
• High discrimination creates a broad cutoff, often rejecting every lower-conductive target below a chosen point.

A wide notch around common pull-tab IDs can also reject nickels, gold rings, small pendants, and aluminum tokens. That may be acceptable during a modern clad coin hunt, but it works against jewelry hunting.

Target IDs Move in Real Ground

Target ID charts are useful references, but buried targets do not always read as one neat number. Depth, target angle, corrosion, nearby iron, soil mineralization, and coil sweep direction can all move an ID.

A copper penny lying flat can produce a cleaner signal than the same penny standing on edge beside a rusty nail. A deep coin may also read lower than a shallow coin of the same type.

Before rejecting an ID range, use a short sampling routine:

1. Sweep the target from at least two directions.
2. Watch whether the ID stays within a tight range.
3. Listen for a repeatable audio response.
4. Dig several examples before treating that range as a nuisance target.

A signal that jumps across 10 or more ID points is not a good basis for a tight notch. The target response is already being affected by the ground, nearby metal, or target shape.

Useful starting limits

• One repeatable ID segment: A good starting point for a trash notch.
• 3 to 5 ID points on a 0–99 scale: A narrow rejection range for a well-known nuisance target.
• More than 8 to 10 ID points: Usually too broad for general detecting where jewelry, tokens, or older coins matter.
• No notch at all: A strong starting setting for unfamiliar ground, relic sites, and gold jewelry hunting.

What You Give Up When You Reject More

A quieter detector can feel more efficient in a trashy park, but quiet settings also remove useful information. A rejected pull tab does not disappear from the ground. It can still affect the response from a nearby coin, ring, or relic.

In dense trash, a rejected pull tab beside a coin may distort the coin’s ID enough that a coin-only program misses it. Broad rejection also makes it harder to learn what is actually in the site.

Keeping more of the target range open helps reveal patterns such as:

• A layer of modern pull tabs around picnic tables
• Deep square tabs mixed with older aluminum objects
• Iron and brass concentrations near a former structure
• Tokens or relics that overlap with modern trash IDs

For general detecting, moderate discrimination with broad acceptance above iron is usually the better starting point. It creates more audio, but it keeps more targets available for investigation.

Match the Notch to the Hunt

Choose settings based on the target class you are willing to lose. A coin-only hunt at a maintained sports field calls for a different setup than a search around an old home site.

For a coin hunt, dig enough examples to identify the dominant junk before rejecting it. For jewelry hunting, keep the middle-conductivity range open and use repeatability, audio quality, and depth to decide which signals deserve recovery.

Build a Rejection Pattern in the Field

A notch pattern should come from the ground in front of you, not from a chart alone.

1. Start with notch off or reject only the smallest available segment.
2. Ground-balance the detector and set sensitivity for stable operation.
3. Dig 10 to 15 representative trash signals from the busiest part of the site.
4. Note the repeating ID range, tone, and target type.
5. Reject only the tightest range that repeatedly produces the same nuisance target.
6. Hunt a short section and dig several borderline signals near the rejected range.
7. Reopen the notch if desirable targets appear close to the rejected IDs.

Stop widening the notch when the IDs become inconsistent or when recovered targets begin to include items you would have wanted to keep. A rejected pull-tab range is rarely made up of pull tabs alone.

A small notebook or note card in the field pouch can help keep patterns straight. Record:

• Site type and soil condition
• Coil used
• Sensitivity setting
• Ground-balance method
• Rejected ID range
• Targets recovered near that rejected range

If you change the coil, search frequency, or ground-balance approach, build the notch again. A pattern that worked in one site condition may not behave the same way after a major setup change.

Keep the coil cover free of packed soil and sand as well. Debris under the cover adds separation between the coil and target and makes weak or unstable signals harder to interpret.

Know Your Detector’s Notch Controls

The detector’s control layout determines how precise a custom notch can be. Read the manual’s discrimination and notch chart before building a pattern.

Look for these controls and limits:

• Target ID scale: Some detectors use a 0–99 scale, while others group targets into broad segments.
• Notch resolution: Several independent ID blocks allow finer control than one large middle segment.
• Accept and reject controls: Some detectors let you toggle individual segments; others use a movable notch window.
• Search-mode behavior: Notch settings can differ among park, field, beach, and all-metal modes.
• Profile storage: Saved programs can help when returning to the same type of location.
• Factory reset process: A reset provides a clean baseline after a custom program becomes confusing.

A detector with broad segments calls for extra restraint. Rejecting one large middle segment can remove too many target types for general-purpose hunting.

Use Audio and Coil Control When Notch Is the Wrong Tool

Skip broad notch rejection when target variety matters more than a quiet hunt. Older properties, fairgrounds, cellar holes, ghost towns, and mixed-use sites can produce coins, jewelry, relics, and tokens across overlapping conductivity ranges.

If your detector offers tone breaks or iron audio, those controls can be more useful than muting a whole range. A different tone lets you hear a questionable target and decide whether to investigate it. A rejected notch removes that decision before the signal reaches your ears.

Notch also does not solve poor target separation in dense trash. When adjacent targets are blending together, use a different approach:

• Switch to a smaller coil when available.
• Slow the sweep speed.
• Keep the coil level and close to the ground.
• Use shorter sweeps around a suspicious signal.
• Overlap passes from more than one direction.
• Investigate repeatable non-ferrous chirps near iron.

These methods help isolate neighboring targets. Adding another rejected ID band does not.

Mistakes That Hide Good Finds

Avoid building a custom notch from one target. A crushed can tab or bent bottle cap can produce a misleading ID and create a reject range based on a single unusual object.

Do not copy another detectorist’s ID numbers directly. Two machines with 0–99 screens can assign different values to the same target, and a different coil or search mode can change the response again.

Do not use broad rejection to deal with iron contamination. Iron affects nearby targets through masking and blending, not simply through its own ID. Slow down and investigate repeatable non-ferrous responses instead.

Finally, do not leave a coin-hunting notch active when switching to jewelry or relic hunting. A setting built to silence pull tabs can also silence the small gold items, tokens, and low-to-mid conductive relics you intended to find.

Bottom Line

Use one notch segment or roughly 3 to 5 Target ID points at a time, and apply it only after repeated digging shows that the range is dominated by junk.

Keep broad acceptance for jewelry, relics, old coins, and unfamiliar sites. Use a narrow trash notch for focused modern coin hunting or cleanup work where the same nuisance target repeatedly fills the ground.

The useful setting is not the quietest one. It is the one that removes a known nuisance target while leaving the rest of the target spectrum open.

FAQ

How wide should a notch be on a 0–99 metal detector scale?

Start with 3 to 5 ID points. Expand the range only when repeated recovered targets show the same unwanted material across a wider and stable band.

Should I notch out pull tabs?

Notch out pull tabs only when modern clad coins are the sole target. Pull tabs overlap heavily with gold rings, small jewelry, nickels, and aluminum tokens, so jewelry hunters should keep that range accepted.

Is notch discrimination better than high discrimination?

Notch discrimination is more selective because it rejects a chosen band while leaving lower and higher IDs available. High discrimination acts as a broader cutoff and removes every target below the selected point.

Why do targets read differently from different directions?

Target angle, depth, nearby metal, mineralization, and corrosion can change the electromagnetic response. A signal that repeats cleanly from several directions deserves more attention than a number that appears once.

Should I use notch settings at an old home site?

Avoid broad notch settings at an old home site. Old coins, buttons, brass fragments, tokens, and relics can produce varied IDs, and many good targets sit close to iron or modern trash.