Tips and Tricks for Advanced Metal Detecting with the Garrett ACE 400

Having used the Garrett ACE 400 metal detector for a few years now alongside my ACE Apex, I have gained a better understanding of the metal detector that is considered a beginner to intermediate-level machine.  I have uncovered some incredible relics and coins other metal detectors have missed and gained a deep understanding of how to get the best results while out detecting with the ACE 400.

The Garrett ACE 400 sits at the top of the list for me when it comes to affordable metal detectors that can be used well after the user has left the beginner level. Some metal detecting enthusiasts will convince themselves they must spend a lot of money on a metal detector to get results. That is simply not the case. With the right skills and knowledge, the ACE 400 will be a detector that can be used for many years to come. 

In this article, I hope to help current users of the ACE 400 get more results when out detecting. We will go over the options for searchcoils, settings, and other tricks to help detectorists gain a better appreciation and understanding of their Garrett ACE 400 so they can come away with better results and help to increase appreciation for one of the top affordable metal detectors on the market. 

Searchcoils Available for the Garrett ACE 400

A must for any metal detector is the option to work with different search coil sizes. Most of the metal detectors I consider beginner-level only have the option of one standard coil. They aren’t adaptable to changing needs of a detecting location. With the ACE 400, there are multiple searchcoil options depending on the needs of the detectorist. Having an assortment of coil sizes is useful for maximum gain when detecting farm fields, old homesites, parks, or beaches.

Below is a list of the coils Garrett manufactures for the ACE 400, their sizes, and when they may be of use. There are other coil manufacturers on the market, but for the purpose of understanding how coil size can make a difference, I will keep the search coil list specifically to the ones Garrett produces. The coils listed below are compatible with the Garrett ACE 200/300//400 metal detectors. Make sure when purchasing a new searchcoil that it is compatible with the detector you are using. 

Coil Name	Size	Uses
Super Sniper	4.5-inch	Handy for use on trashy sites where desirable targets are mixed with iron-rich targets that can mask ‘good’ targets
Viper DD (my personal favorite)	6” x 11”	Great all-around coil for coin shooting and relic hunting. Good for narrow sites such as forests as well.
Reaper DD	14” x 11”	Great for all target sizes, but increased depth for medium to larger items. Useful for field hunts where increased coverage is needed in open locations.

Garrett PROformance ACE Series Coils (DD or Concentric)

Coil Name	Size	Uses
PROformance DD	5” x 8”	Great all-purpose coil for gold, relic, and coin recovery.
PROformance DD	8.5” x 11”	All-purpose but handier in locations that are not overly trashy – handy for mineralized soils
PROformance Concentric	6.5” x 9”	Good for trashier sites
PROformance Concentric	7” x 10”	Handy for small to medium target recovery in trashy locations – better for us in lower mineralized surfaces
PROformance Concentric	9” x 12”	Useful for low mineralization surfaces – covers larger area

At this point, you may be wondering what the difference between concentric and double-D (DD) coils is. If you look at a DD search coil you will notice what looks like two ‘D’ shapes overlapping each other back-to-back with a blade-like opening in the center. The center of the DD coils is where the electromagnetic field (EMF), or sweet spot,  is concentrated and is where the pinpointing feature will narrow the location down to. 

With concentric coils, the EMF is the size of the coil and narrows as it goes further into the ground. Some refer to the shape of the EMF with concentric coils as a cone or ‘V’ shape. You will need to overlap your swings more with a concentric coil, but they can be a bit more precise compared to the DD coils when it comes to pinpointing a target. 

Be aware when you change your coil on the ACE 400 you will need to reset your machine to factory settings by holding down the power button until you hear the double-beep. This simple step is a must to make sure your detector functions properly with the coil and is necessary each time you change your search coil. 

The best advice I can give when it comes to coil preference is to try different coils to see which works best for your machine and hunting conditions. Ground mineralization and conditions of the site, such as an abundance of nails and other iron or trash objects, are key factors to consider when choosing a coil. Personally, I mostly hunt wooded sites and old homesteads I use the Viper coil for most of the day. It’s small enough to get good coverage in the woods and also works wonders on old homesites littered with trashy targets. For fields, I use a larger coil to gain more coverage.

Garrett ACE 400 Settings to Increase Finds

Knowing the best settings for your ACE 400 can help drastically increase desired target location in any setting. A beginner user will likely run their detector with one standard setting each time they are out detecting. An advanced detectorist will know when to adjust functions for prime recovery and accuracy. 

The ACE 400 comes programmed with five pre-set search modes which include:

• Zero Disc
• Jewelry
• Custom
• Relics
• Coins

Detectorists who search for both coins and relics find the Zero Discrimination most useful. This option is the one I tend to run most often other than Custom. A detecting site that once held a home will likely have an abundance of targets in all ranges. When I get to a trashy site where time is limited, I tend to discriminate out the targets below 35. This will limit the amount of iron interference, but you may miss small gold items. Setting your ACE 400 up with some level of iron discrimination also helps the Iron Audio feature to work properly as well. 

Iron Audio in conjunction with discriminating out, or quieting, low iron targets is incredibly useful. I don’t know how many times I’ve hit a desirable tone and dug it only to discover it was an old rusty bottle cap. It happens to the best of detectorists. That’s where the Iron Audio feature is useful on the ACE 400. With your detector set up to notch out some tones, you can turn on the Iron Audio feature whenever you get a target that may be questionable and Iron Audio will produce a grunting sound alerting you that the target is likely not what the tone or VDI is showing. Master this technique and you will save time in the field digging undesirable bottle caps. 

Be warned that the Iron Audio is not your best indicator at all times that a target is undesirable. A coin could be situated next to a nail and the grunt will occur as well as a consistent high tone. Dig it. Better to take a minute to double-check than to miss an old piece of currency that is resting with an old rusty relic or nail. 

If I am at a location to locate a lost item, then I will set my Custom mode to notch out all targets I am not trying to locate. If I know I am searching for a lost silver ring, I will notch out up to about 65 to save me time from digging countless holes in my search. This way, I won’t miss the target which may be situated amongst targets that could mask the one I am searching for. I will also incorporate the Iron Audio with this search mode to make sure I’m not digging those pesky pull tabs we detectorists know too well. 

I rarely use the Coins mode, but if you are a coin shooter or park hunter this would be a good preset to use. You will silence the targets that are relics or trash and only pick up on the high tones you are searching for. Same with the Relics mode, I will use this preset when I have hit a site many times and I want to see if there are relics I missed while running the Zero Disc mode. 

The next setting to consider is sensitivity. Do not think that cranking that sensitivity up will do you any justice. Turn your ACE 400 on and dial the sensitivity up all the way to see what results you get. It will be noisy and you will spend a lot of time digging small targets that are likely not as desirable as you thought they may be. Or you will go mad with the amount of chatter the 400 is putting out. 

I rarely run my ACE 400 higher than five or six notches on the Sensitivity. I am a relic hunter, and if I do increase sensitivity then it usually will occur in large open farm fields where targets are scarce or at sites I’ve hunted multiple times and are fairly free of trash targets. If you run into interference from electric lines or other detectors in the area, tuning your sensitivity can help quiet your machine a bit for maximum performance. 

You also have the option to change the frequency your ACE 400 is operating on as well. The 400 operates at 10kHz but has the option to adjust the frequency slightly to eliminate interference. This is useful at group hunts where multiple machines are running. You can cycle through the options F1-F4 to find the best frequency for the conditions you are detecting in. 

Metal Detecting Tips for Better Results from Your ACE 400

There are quite a few tips that can be useful despite the metal detector you are using. Each of them is handy to know and understand to increase your finds.

• Remember that metal detectors are searching for coin-sized items. If you are getting a mid to high tone use the wiggle method and lift your coil off the ground slowly while doing so. If you are still hearing a tone when your coil is being raised, you are likely hitting on a target that is much larger than a coin. 
• Keep your coil parallel to the ground and keep a slow and consistent swing speed while overlapping your coil sweeps as you go. 
• When you reset your detector after installing a new coil, remember to reset your sensitivity and other settings. 
• Do not always rely on the VDI number. I tend to dig based on the tone I receive. I like to dig the mid and high tones when at a site. 
• Don’t be afraid to dig the repeatable low tones in search of gold. 
• Change your sensitivity when you change locations from trashy to wide-open fields. 
• Carry extra batteries for your ACE 400.
• Don’t be afraid to detect in shallow streams and rivers. The brain, or yellow box, of the ACE 400 is NOT waterproof but the coil is. Adjust the settings to eliminate chatter.
• Listen to your machine. If it’s noisy, it is working overtime and your settings need to be adjusted. 
• Have fun and don’t be afraid to reach out to fellow detectorists for advice. 

In conclusion, the Garrett ACE 400 will only be as advanced as you want it to be. I have uncovered post-War of 1812 buttons, old coins, and other incredible finds by learning what my ACE is communicating. You will need to spend at least one hundred hours with any detector to fully understand it and become the advanced detectorist you strive to be. There are countless videos available that can help increase your skills. Advanced detectorists such as Garrett Field Team member Gypsy Jewels of Zero Discrimination on YouTube is a great place to turn to for tips to increase your understanding and skills with the ACE 400. 

The Garrett ACE 400 is a reputable machine trusted by many advanced detectorists. Many in the hobby know the ACE 400 is a master at finding silver. Do not be afraid to experiment with settings to find what works best for you. The advice listed above is merely a guide to help you become a better advanced detectorist. With a little practice and the right tools, you will be well on your way to uncovering the lost history hidden beneath our feet that the basic metal detecting enthusiasts miss. Happy hunting. 

Coins, Tokens, Buttons, Pins, and Relics
found with the Garrett ACE 400