Monolith

I had HifiMan He400i and I found them so boring and with too weak bass, I have now Monolith M1060 i like them a lot but they miss detail, my other headphones are HD600, Meze 99 Classic and AKG k712 pro. which should be the right choice with a 500ish USD budget? ty

I've recently come across a few headphones that are swappable between open-back and closed-back. For instance, HiFiMan's Edition S and Monoprice's Monolith M560. I was wondering how many of these are out there. Are there any that are on par with regular audiophile grade headphones?