My MOBO is NZXT Z690 N5. and the shp9500 sound waaaaay too quite tried front and back connectors. windows volume on max. tried apple dongle and it made them even quieter. recommend a fix if it’s fixable or an amp/dac that will drive them without breaking the bank. i got my eyes on SYBA DAC but it’s not available or shippable to me.
Hello 
Can you get the Fiio KA11 or Shanling UA Mini ($30)? It is a dongle DAC like the apple one but with 200mW at 32 Ohms which should be plenty for your headphone.
Once I had the Creative X1 which was nice too. Build in EQ and a usable “surround” function which doesn’t destroy the sound but just added a touch of width and dimension to the sound ( not the SXFI function). With 100mW it is still powerful enough. It has volume buttons and supports an microphone ( Fiio and Shanling does not)
Fosi K5 Pro has a volume knob if you want one + microphone + tone controls.
But…Are sure you are not limiting the volume somewhere else if not in windows? SteelSeries GG Sonar or any other additional software? Too quiet sounds strange, even for a apple dongle or onboard sound card. Did You try it on another device? Apple dongle on a phone for example.