"Let's say DM have "entry basshead level" bass, and New Aten have "serious basshead level" bass"
Sorry but my DMs definitely have much more than entry level bass in both amount and quality. Your copy doesn't, but my DM is fantastic and has. I have the TFZ No3...they just can't be compared. DM is multiples better in every respect. I don't think you have a DM that produces what Bob intended.
I think, speaking of levels of bass, we imagine different levels that we can describe as "entry" or something else. I started my headphone journey from Sony MDR-XB950AP, which is known for absurd quantities of bass that can make your eyeballs shake. But I thought that it's not enough, because there still was some poor mastered songs with almost no bass in them, so I EQd my Sonys earthquake-like bass to the roof. I've listened them in such setup for 4 years, and I could continue doing that, but they were in a very poor condition after all this time. That's why nothing of what chi-fi brands could offer me satisfied my basshead needs. BLON BL03? Tonally they're still at the top 1 in my list, but bass is just meh... Audiosense AQ0, which was very often described as basshead IEM, was actually fun, kinda BLON-like, but darker and warmer. And again, that's not what I can call basshead territory, but they were somewhere below my minimal requirements, pretty close, yet still far away. TFZ Live X is what I can rate as one and only basshead chi-fi IEM. They have awesome drums, comfortable treble, but very poor, even claustrophobic soundstage when using narrow bore eartips. But enough of that. The conclusion is:
First: my basshead preferences is much above of the regular users, probably because of 4 years with those Sony scull crushers affected my hearing on low frequencies.
Second: I don't think that my DM is faulty in any way, because there's a lot of bass, it's just a bit lower in quantity than New Aten's bass, due to smaller driver size. But, and there's a big BUT: DM's bass is better qualitively. It's much harder, more focused, a lot more fast and aggressive, compared to New Aten's huge, thumpy, hip-hop-like bass. DM's one is also digs deeper.
Last: I agree that TFZ No.3 isn't comparable to DM, what I wanted to say that the sound signature (elevated bass, edgy upper mids, relaxed treble) is pretty similar to my ears.
Also, there were so much people that told me: "Hey, that IEM is a true bass cannon, it kicks so much that I couldn't stand it and sold it recently, you should definitely try it, you won't be dissapointed, promise". And then, I was dissapointed yet again.