Best Answer Triryche , 09 May 2014 - 04:53 AM
All 5 speakers are always on. Crossovers determine which frequency range goes to which speakers.
The guitar in is expecting an Instrument Level signal, the aux-in is Line Level, so for processors you will definitely want to use the aux in.
Also, the aux is stereo in, the guitar-in is mono.
For regular stomp boxes you would use the guitar in.
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