I very much agree with you - I would use more fans on the outside enclosure, possibly behind more barriers so the sound is never direct (it has to bounce off walls before getting out). Eg a vent cover on the outside or simply vents mounted inside the case (not directly on the outside hole).
(Possibly also keeping the positive pressure inside the enclosure for dust control.)

However there might be an argument about HDD noise that is fairly particular to the drive models.
Maybe op just doesn't like noisy HDDs & isn't that bothered by fans (I centrally am more bothered by enterprise HDD noise than the noise of quality fans), so the solution is HDD-noise oriented (and I think it works in that regard).

(And yes, I do pick my HDDs by noise too.)

Yes

*hella

If it's just a media server that spends 99.5% of its life idling, temps might not actually be that bad.

Yeah, seems a second fan would help with air flow into/out of the case. Depending on how air tight everything is when it's closed.

how it affects the temperature

positively... 🔥

That looks like the Fractal Define 6 case which already has built in soundproofing. I have mine on a desk doing the exact same job with even more drives and I don't even hear it from a couple feet away.

Edit: actually not a Define 6 after looking closer. Mine doesn't have those weird latches on the side panels despite otherwise looking identical.

not op, but yeah looks like. my old gaming tower is about to get debian installed and go on perma server duty, and the onboard wifi has an antenna like this, which may let me leave it in the garage.

The one I have that looks like that is bluetooth.

Not op, but went snooping. Looks like it might be on the left.

https://lemmy.world/post/20717184