Sorry be this vague, but we use the term aux splitter for an audio/headphone splitter (with 3.5mm jacks). And yes you are correct markw, that was indeed what I was implying. Am I correct to asume you are saying you can not combine 2 audio inputs into 1 amp, but that you can however use one audio input for 2 amps (which was my question).
What I mean with an rca splitter is a cable/device which has 1 rca input and several outputs to connect to amplifiers. Would this result in better sound?