Subnautica 2 Feedback Resonator: where to find it and how to upgrade the Sonic Resonator

The Feedback Resonator is one of those items that Subnautica 2 doesn't exactly flag on the map. As a result, plenty of players end up circling the Alien Ruins without ever getting their hands on it. This guide covers the two locations you need to scan, and what you should have on hand before heading to the Modification Station.

Feedback Resonator location

In Subnautica 2, you need to scan two separate fragments to unlock the full recipe. Both locations are found around the Alien Ruins - that's your starting point for both.

The first fragment is located by heading east from the Alien Ruins. Cross the area known as Angel's Ridge, then keep going toward the northeast. Count roughly 1,300 meters from your starting pod: you'll fairly quickly spot an area of distinctive green water pools, that odd little acidic biome the community has nicknamed the "green zone." That's where the first fragment is hiding, deep down. Upgrade your Seaglide before diving - without it, you simply won't reach the right depth.

Tip

Watch out, a giant squid lurks in this area and can attack your vehicle, so leave your Seaglide outside and go scan the Feedback Resonator on foot.

Once you've scanned the first fragment, head back to the Alien Ruins. The second fragment is this time located between east and southeast. As you move in that direction, you'll spot ruins in the distance - and among them, a Cicada wreck with its doors wide open up high. Go inside. The second Feedback Resonator lies directly on the floor inside. Less suspense than the first one, but the area is still dangerous: don't overlook your surroundings.

A comment from the Reddit community sums up the situation nicely:

"The acidic green zone contains several resonator upgrades - once you know where to look, it's a lot less of a pain." - r/Subnautica_2 thread, "Where to find resonator upgrades" discussion

Sonic Resonator upgrade

Once both fragments are scanned, head back to your base. The upgrade takes place at the Modification Station - if you haven't built it yet, now's the time to do so, since it will be essential throughout your progression.

Once you're in front of the Station, open the prototype tool modification menu. That's where the Sonic Resonator upgrade option appears. And watch out for the materials required: this isn't low-tier scavenging. You'll need at least two Conductive Crystals, plus, according to community guides, some enameled glass and strontium. Rare resources, in other words. Plan your farming ahead of time before you dive in, and you'll save yourself an unnecessary trip.

Honestly, the upgrade is worth it. The upgraded Sonic Resonator genuinely changes the way you interact with certain locked areas and certain enemies - it's one of the most useful tool upgrades in early access right now.