Hi, with the S9 Pro try a balanced connection, that will significantly increase the power output. (But it will cost something...) Also, DCA phones are more sensitive than most to a snug fit in order to provide full bass. This is generally true of closed back phones, but the high "resonance frequency" of the DCA headphone increases the bass sensitivity.
With a balanced connection and always a snug fit (due, I guess to the shape of my head), the Noire shivers my timbers when the music asks for it. I have another dongle, the E1DA 9038s G3, that also works well and has high current delivery (balanced only, unlike the Hidizs).
I like my Hart Audio balanced headphone cable, and as these things go, they're not as expensive as some. The DCA's have a specialized connector where the cable joins each ear cup that I like a lot, but that is not that common ... Hart has them:
https://hartaudiocables.com/collect...ush-pull-mr-speakers-balanced-headphone-cable (Be sure to match your source connector as well.) I guess you can go on AliExpress.com and maybe find some cheaper ones if you're lucky, but if so, you may have to wait for delivery from China.