Resetting sound fields to the initial settings, Using only the front speakers and, Sub woofer (2ch stereo) – Sony HT-DDW685 User Manual
Page 45: Resetting sound fields to the initial, Settings, Using only the front speakers and sub woofer, 2ch stereo), Press 2ch, Press ? / 1 to turn off the receiver, While holding down 2ch, press ? / 1

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