Subnautica 2 Guide: How to Get the Feedback Resonator

Getting locked out of crucial alien technology because a parasitic plant keeps dodging your tools is enough to make anyone quit the expedition.

If you have finally reached the Alien Ruins roughly 1,800 meters east of your starting point, you probably found the massive Angel Comb sitting underneath the broken power plant. You need to clear this flower to unlock the Axum Vision adaptation and read the alien language. The problem is that the Bloom Cankers infecting this specific plant are armored. If you get close with your standard Sonic Resonator, they snap shut and block your blasts. To fix this, you have to upgrade your gear to the Feedback Resonator, which fires sonic projectiles from a distance.

Prepping for the Deep Ruins

You cannot just swim out and grab these fragments. They sit deep inside the Root Canyon biome.

Before you make the trip, you need to fully upgrade your Tadpole depth modules so your vehicle does not crush under the pressure. You also need to secure the Bioscanner upgrade from the Iso blackbox to properly analyze the alien tech.

Also check out: Subnautica 2 Guide: How to Unlock All Biomods and Find the Bioscanner

Finding the Blueprint Fragments

The two fragments you need are scattered in the dangerous zones surrounding the Alien Ruins. I highly recommend using the main Angel Comb structure as your central landmark instead of trying to navigate 2,000 meters from your Lifepod.

Fragment 1: The Metal Farms

Start at the Alien Ruins Angel Comb and face northeast. Follow the massive purple roots running along the sand until you spot a bright green and yellow glow in the distance. This area is known as the Metal Farms.

Before you drive your Tadpole straight into the glowing pools, park it a safe distance away. There is a giant squid leviathan patrolling the waters near the surface. If you drive right in, that creature will turn your sub into scrap metal and send you straight back to the Lifepod. Swim the rest of the way by hand. The first Feedback Resonator fragment is sitting on the ground right near the edge of the yellow pool.

Fragment 2: The Cicada Wreck

For the second piece, return to the Angel Comb and head east. You are looking for a plateau holding a massive crashed ship called the Cicada Wreck. This is the Therapy Room section of the ship, and it sits right on the edge of the Root Canyon biome near the Singh blackbox signal.

Look for the open doorway facing south and swim inside. Look immediately to your left near a charred, broken door. The final Feedback Resonator fragment is resting on the floor.

Crafting the Resonator Upgrade

Once your PDA logs the full blueprint, you have to head back to your main base. You cannot craft this in a standard Fabricator. The Feedback Resonator is a direct tool replacement that requires a Modification Station.

The shopping list for this upgrade forces you to gather some incredibly specific mid to late game materials.

Clearing the Infection

Now that you have a ranged sonic weapon, you can finally deal with the shielded cankers.

Head back to the massive Angel Comb at the Alien Ruins. Stay back at a safe distance so the blue pustules do not snap shut. Charge up your Feedback Resonator and fire sonic projectiles at every single node along the tendril branches. One branch dips into a ravine below the base, and the other leads right back toward those Metal Farms. Once you destroy the final canker, the pink bulb will open, allowing you to secure the Axum Vision DNA mutation.

Still struggling to survive on Proteus? Check out my complete Subnautica 2 Guide Hub for base building tips, resource maps, and more.