I have a Marshall cab with the 4/8(st)/16 ohm selector on the back. I have always used it in the 16 ohm setting with my Reinhardt 18 watt head set at 16 ohms. For kicks the other day I switched both the head and cab to 4 ohms and noticed a definite tone difference. In the 4 ohm setting, it sounded like it had a lot more low end punch to it, more meat. Am I just imagining things? I thought the tone would basically be the same and that the head compensated for the load setting? If I'm not crazy, why do most guys I hear of use the 16 ohm setting over the 4 with a Marshall head? Thanks for any info!