I guess this thread has slowed down, now that anything good to say is 'preaching to the choir'. But still, I'm quite impressed by the bass response on certain songs.
If any of you have Tidal and a decent set-up (and like Hip-Hop) try listening to Lil Wayne's FWA song "I Feel Good", the bass frequencies on that track as well, as much of the album will literally rattle your head and reach you all the way down in the gut.
While I wouldn't necessarily describe these as basshead cans, their ability to stay clean and un-distorted down in the lower frequencies is really amazing. Lately, I've been putting a lot of attention to my source (i.e., my computer, cables, and DAC) and realizing that these cans continue to step up to any game I throw them. With a really good system you can actually get some pretty intense high frequencies out of them, as well. That means that really bright albums still sound really bright.
After more comparison with the AKG 501, I've concluded that the DT150 is a more hifi can, but still for certain types of music the AKG 501 is going to offer more transparency in the upper mids, as well as a more forgiving presentation of poor recordings. The 501 seems to hit a plateau where there just isn't that much more to squeeze out of them, due to their soft low end and lack of truly extended highs. Also, I continue to find that with the right attention to the front end of my system I'm increasingly satisfied with the soundstage of the DT150. Using programs like Fidelizer Pro and Jplay with Tidal, or with WAV files on my computer when I make it go into hibernate mode it's amazing the kind of space you can get from these phones. The sound is way outside my head. And then again, the bass is just so tight with my Lehmann BCL in high gain. I'm sure there are other amps that can do this as well. In fact my Schiit Magni has plenty of bass quantity, it's just not as tight and clean as the Lehmann BCL I'm using.