Contact
One address, read by a person. There is no ticket system to fight with.
Useful things to include: your account email, roughly when the problem happened, and — if a separation failed — the job link. That is usually enough to find it without a back-and-forth.
Copyright concerns
If you believe material processed through this site infringes your rights, write to the same address with the work in question and how to verify your claim. Uploaded audio is deleted on a fixed schedule and is never published — there is no public library of user uploads here — but we will act on anything we can act on.
Not the Demucs project
Bugs in the model itself, questions about training, or anything about the upstream code belong at github.com/facebookresearch/demucs, not here. We run Demucs; we did not write it and we cannot change it.