As far as I know the C405 is Versalink, not AltaLink, so here is how its done on both.
AltaLink is Device > Tools > App Settings > Fax App > Fax Volume
Versalink is Device > General > Sounds > Fax Processing Tones
As far as I know the C405 is Versalink, not AltaLink, so here is how its done on both.
AltaLink is Device > Tools > App Settings > Fax App > Fax Volume
Versalink is Device > General > Sounds > Fax Processing Tones