Sony STR-DN1080 Manual page 149

If you do not use the subwoofer, the front speakers are automatically set to [Large].
[162] Adjusting Settings
Setting the crossover frequency of the speakers
(Crossover Frequency)
You can set the bass crossover frequency of speakers for which [Size] in the [Speaker Settings]
menu has been set to [Small]. A measured speaker crossover frequency is set for each speaker
after the Auto Calibration is performed.
Select [Setup] - [Speaker Settings] from the home menu.
1
Select [Crossover Frequency].
2
Select the speaker for which you want to adjust the crossover frequency on the
3
screen.
Press / to set the crossover frequency.
4
Note
This function does not work in the following cases:
Headphones are connected.
[Bluetooth Mode] is set to [Transmitter].
[Size] for none of the speakers is set to [Small].
The surround back speakers will be set to the same setting as that of the surround speakers.
[163] Adjusting Settings
Assigning the surround back speaker terminals
(Surround Back Speaker Assign)
You can set the assignment for the SPEAKERS SURROUND BACK/HEIGHT terminals.
Select [Setup] - [Speaker Settings] from the home menu.
1
Select [Surround Back Speaker Assign].
2
Speaker Settings
Speaker Settings