Tested on external hard drive WD MyPassport => Impeccable in full full full including the sound from comments from a headset plugged facade.
Not tested with a hard drive directly installable inside (from below). 2 hard drives 2.5-inch heights are possible.
Attention all the same, the doc is in French completely. The largest part is in English but it is very intuitive ... Nevertheless, thank you Dad ...
It remains to see if the firmware is upgradable via the LAN (Internet).