I do talk extensively about the sound signatures of these headphones in my original reviews, both of which are linked in the article you replied to, but I’ll go ahead and link them again here just for convenience!
I no longer own the HRM-6’s so I can’t speak with perfect authority at this point, but they were designed more to split the difference between consumer and studio gear. The two AKG models above are tuned to match the Harman target, which means they have a flat, accurate style of bass. The 371 is a little closer to the target, and a little more meaty in the sub bass and in general, but both offer pristine accurate sound. They don’t lack bass whatsoever, but they present it exactly as it is in the source material.
The HRM6 was designed to be a little more thumpy and aggressive in the bass than either of these models to appeal to consumer listeners and for DJ monitoring use, so if that’s a part of what you like about them, you’re better off sticking with those! :)
Thanks for reading!