Butterfinger
AKA GNR4EVER
which one is the best for bass?
no i'm asking th 909 vs lcd x 21 not th900
For bass, I think the 909. Is it amazing? No. But neither is the LCD-X, plus that one has more issues with the tuning.
EQ a TH900mk2 as GH said and it's one of the hardest hitting most extreme and energetic headphones. But I realize it's closed and you don't want to EQ.
Without EQ as long as you have significant power, the Hifiman HE6SE v2 will get closer to the 900. It has the ability to hit hard with very little distortion, which is what makes the 900 special. Tuning is also better on the HE6SE.
You could also consider Kennerton anything from the Magni (I haven't listened but folks compare to Emu Teak) to the Gjallorhorn(closed)/Vali(open) for dynamics. If you want bass then Kennerton should probably always be on the list.
Emu Teaks are semi-open imo and if you decide to get the 909 you're using the same hinge system as the Teaks but at 4x the cost because different drivers and red cups.