Sony STR-DN1080 Manual page 148

Adjust the distance.
4
Note
Some parameters may not be available depending on the speaker pattern setting.
[Distance] cannot be set in the following cases:
Headphones are connected.
[Bluetooth Mode] is set to [Transmitter].
[161] Adjusting Settings
Adjusting the speaker size (Size)
You can adjust the size of each speaker (front left/right, height left/right, center, surround
left/right, surround back left/right).
Select [Setup] - [Speaker Settings] from the home menu.
1
Select [Size].
2
Select the speaker whose size you want to adjust from the following.
3
Front, Center, Surround, Height
Select the size you want.
4
Large: If you connect large speakers that will effectively reproduce bass frequencies,
select [Large]. Select [Large] usually.
Small: If the sound is distorted, or you hear a lack of surround effects when using multi
channel surround sound, select [Small]. You can activate the bass redirection circuitry
and output the bass frequencies of each channel from the subwoofer or other [Large]
speakers.
Note
[Size] cannot be set in the following cases:
Headphones are connected.
[Bluetooth Mode] is set to [Transmitter].
[Speaker Pattern] is set to [2.0].
Hint
The surround back speakers will be set to the same setting as that of the surround speakers.
When the front speakers are set to [Small], the center, surround, and surround back/height speakers
are also automatically set to [Small].
Speaker Settings