You can change the fax transmission or reception speeds using the following procedure.

From the operation panel on the printer:

1. Press the Setup button.
2. Use the Left Right arrows to select Fax settings and then press the OK​ button.
3. Use the Left Right arrows to select Adv. fax settings and then press the OK​ button.
4. Use the Left Right arrows to select Adv. communication and then press the OK​ button.
5. Use the Left Right arrows to select TX start speed or RX start speed as desired, and then press the OK​ button.
6. Use the Left Right arrows to select to select desired speed (*33600 bps, 14400 bps, 9600 bps, 4800 bps), then press the OK​ button.

* = default setting