Unintentional ASMR comes from videos that were never meant to be ASMR, like quiet demonstrations, tutorials or archival footage. These channels collect or create that kind of calm, accidental content.
Unintentional ASMR channels are rarely made by ASMR creators. Most are craft, cooking, restoration or instructional channels whose calm voices and quiet work happen to have the same effect, and some collect and re-upload such clips.
Common sources include craft and restoration videos, home cooking, art tutorials, barbershop footage and old instructional films. Because nobody records with ASMR in mind, background noise, wind and room echo vary far more than on made-for-ASMR channels, and uploads follow the channel's own subject rather than any trigger.