Brother HL-L9200CDWT - Manual (Page 122)

General Information
115
3
Quiet mode feature
3
The Quiet mode setting can reduce printing noise. When Quiet Mode is turned on, the print speed becomes
slower. The default setting is Off.
Turning Quiet mode on/off
3
a
Press .
b Press General Setup > Ecology > Quiet Mode.
c Press On or Off.
d Press .
NOTE
If your machine has been set to Toner Save On, you cannot set Quiet mode to On.