Quick answer
Get the Sonic Resonator first, then scan two Feedback Resonator fragments in the glowing green abyssal pool / Metal Farms route northeast of the Alien Ruins Research Base. PC Gamer places that run roughly 870m at bearing 75 from the Research Base and around 450m deep, so bring the Tadpole Depth Module, Repair Tool, healing, and a real exit plan. Current recipe data lists Sonic Resonator x1, Enameled Glass x2, Conduit Crystal x2, and Strontium x2 at the Modification Station. You need the upgrade for ranged Bloom Canker clearing on the Axum Vision Angel Comb route.
Field notes for the deep scan run
This route punishes casual prep
The distance, depth, and return path matter more than the fragment count. If Tadpole depth, repairs, or healing are not ready, the two scans can become a messy rescue trip.
Stage the recipe before scanning
Enameled Glass, Conduit Crystal, and Strontium are all expensive enough to deserve a checklist. Gather them before the scan run if you want the upgrade built the same session.
Build it for Axum Vision, not just collection
Feedback Resonator is most useful when it immediately feeds the later Angel Comb route. Treat it as a key for ranged Bloom Canker clearing.
Feedback Resonator route plan
Start with the Sonic Resonator
Feedback Resonator modifies the Sonic Resonator. If the base tool is not built yet, this route is premature. Use the Sonic Resonator for ore, Bloom Biofilm, and Conduit Crystal prep before you spend time hunting the upgrade.
Treat the scan as a 450m job
PC Gamer puts the two fragment scans in the glowing green pool and Metal Farms area northeast of the Alien Ruins Research Base, around the upper edge of Tadpole Depth Module comfort. If the vehicle depth warning is still part of your life, wait.
Scan two fragments, then leave cleanly
Subnautica 2 Guide also lists two scans for the blueprint, with known fragments around wreck, mine, and Karakorum Metal Farms routes. Mark what you find. This is a bad area to keep wandering after the blueprint unlocks.
Craft it at the Modification Station
Current data agrees on Sonic Resonator x1, Enameled Glass x2, Conduit Crystal x2, and Strontium x2. PC Gamer also notes that the Modification Station blueprint can be found inside the Alien Ruins Research Base if you still need the station.
Use range on Bloom Cankers
Subnautica 2 Guide describes the tool as firing a blast projectile with longer range, and PC Gamer ties that directly to viral flowers that close when you approach. Do not force a close swim. Back up and shoot.
Use it immediately for Axum Vision
Axum Vision depends on clearing Bloom Cankers around three Bloom Nodes and the central Angel Comb. Once the upgrade is built, the next useful route is not random mining. It is the Angel Comb chain that unlocks Karakorum Power Plant consoles.
Route card
Tool
Sonic
Base tool first, ranged upgrade second.
Depth
450m
Green pool and Metal Farms route needs depth planning.
Use
Axum
Clears Bloom Cankers for the Axum Vision route.
Before you leave base
| Check | Why it matters |
|---|---|
| Sonic Resonator | Required as the base tool, and still useful for ore, biofilm, and Conduit Crystal harvesting. |
| Tadpole Depth Module | The route reaches depths where a basic vehicle plan will feel thin. |
| Repair Tool and healing | The green-pool area is hostile enough that one bad bite can turn a scan trip into a salvage trip. |
| Two fragment scans | Unlocks the blueprint before the expensive craft matters. |
| 2 Enameled Glass | Fabricator material using Glass and Creature Enamel. |
| 2 Conduit Crystal | Found around deeper Alien Ruins / Power Plant routes. |
| 2 Strontium | Processed material tied to Celestine planning. |
| Modification Station | Needed for the Prototype Tool Modification craft. |
This is a late-route tool, not a flex item
The scan route sits near predators, deep structures, Metal Farms, and Conduit Crystal temptation. Pick one main job before leaving base. If the blueprint unlocks, go home and build the upgrade instead of turning the return trip into a sightseeing tour.
FAQ
How do you unlock the Feedback Resonator in Subnautica 2?
Scan two Feedback Resonator fragments, then craft the upgrade at a Modification Station. PC Gamer points to the green abyssal pool / Metal Farms route northeast of the Alien Ruins Research Base.
Do I need the Sonic Resonator first?
Yes. The Feedback Resonator is a modification of the Sonic Resonator, and the Sonic tool is also useful for gathering some of the materials around the route.
What is the Feedback Resonator recipe?
Current public data lists Sonic Resonator x1, Enameled Glass x2, Conduit Crystal x2, and Strontium x2 at the Modification Station.
What does the Feedback Resonator do?
It turns the Sonic Resonator into a ranged tool. Subnautica 2 Guide says its projectile can destroy armored Viral Bloom Cankers from a safer distance.
Why do you need it for Axum Vision?
The later Angel Comb route asks you to destroy Bloom Cankers around Bloom Nodes. Those growths punish close approaches, so Feedback Resonator range is the clean answer.