I prefer my RY4S Mmcx Plus to my MX500 MMCX. My500 seems a little bright and seemed to be a little bass light to me.
I really like the RY4S Plus.. iI have a balanced cable on them but have been using an SE adapter. Not actually tried them balanced yet.
I had the original RY4S quite some years back, but I can't actually recall how they sounded besides them being really good for their price. May I know how you would compare the Plus to the original? If memory serves me right the RY4S already have a good amount of bass. I'm back to using the Kube V1 because that bass and sound presentation is just so addictive. I was hoping to get something in the tune of the Kube V1 but with MMCX, since they are really fragile.