From a science standpoint, synergy might be defined as the combined effect of the parts yielding a greater difference than the summed effects of the individual parts. In science, perhaps unlike audio, studies often deal with real, measurable number$. For instance fertilizer A may cause an increased corn yield of 5% per acre. Fertilizer B may also cause a 5% increase in corn yield. If both fertilizers are applied together, one might expect a 10% increase, but if the increase in yield is 40% or 50%, that is a synergistic effect. As an audio example, maybe amplifier A has a sort of dark, mellow "British warm" sort of sound. With most neutral speakers it could be considered flawed. With a different speaker that has a bright character that would not be favorably reviewed with most amps, maybe that amplifier A would match very well, and the two together could make a very good sounding pair. That would be a synergistic system. Two lesser products each with some shortcomings match disproportionately well with each other. In reality, all/most components have flaws and when a set matches well, or has synergy, it sounds better than it really should. To paraphrase from Rocky Balboa regarding Adrian, (no, I have no desire to see the current version). "I have gaps, she has gaps. Together we fill each other's gaps" Pretty corny huh?