​Question:

Can Input-Y mode be used to make a stereo signal into a mono output on XLS Drivecore 2 amplifiers?

Answer:

No.  The XLS Drivecore 2 does not have summing capabilities.  Input-Y simply uses whatever audio is coming from input 1, for both outputs of the amplifier.  Mostly this is used to bi-amp speakers or run a full range + subwoofer combo, but it can be used to drive full range speakers on both channels.  If you have a stereo signal that needs to be made mono, this would need to happen externally.  Either the source audio device can be set to mono output (if possible), or a summing adapter/cable would need to be used.  Using Y cables to sum an input is not recommended and may cause problems in the source audio device or with the quality of the audio signal.​

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