A Tonal Resonator was a device created by the Dwemer. They were used as stationary gate-openers in which one had to use a bow and arrow, or a Destruction spell, and shoot one of the handles on the Resonator so that it would spin up or down, which would open the nearest gate or door.
In the Dwemer ruin of Arkngthamz, located in Skyrim, several Tonal Resonators appear that must be shot at to open doors. In a large cavern that leads to the room containing a shard of the Aetherium Crest, there are five Tonal Resonators located on a large wall with a gate (two on the top and three on the bottom). These Tonal Resonators must be shot at in a correct sequence in order to open the gate. The correct sequence is as follows: bottom left, bottom right, top left, top right and bottom middle.
The order of the first two Resonators can be found in Katria's Journal, while the second and third are written in a Scrap of Paper found on a dead adventurer in front of the door the Tonal Resonators open.
In the Dwemer ruin of Fahlbtharz, located on Solstheim, contains several Tonal Resonators throughout the ruin. Near the end of the journey towards the Great Hall, are six Tonal Resonators in a large room that represent a very complex puzzle that opens a gate leading to the Great Hall. Though there are six Tonal Resonators, exactly 20 lights need to be lit, which can be achieved by shooting the far left (3), the middle left (4), and the middle right (13) resonators.
Number of lights lit by each valve:
- Far left = 3
- Middle left = 4
- Left closest to center = 6
- Right closest to center = 9
- Middle right = 13
- Far right = 18