Windows 10: Rear audio jack detects my headphones HD600 through Realtek Audio Console notification but...

I bought new headphones Sennheiser HD600 but when plugged into my rear audio jack, it doesnt play audio. When plugged into the front panel audio jack it does work however. Realtek Audio Console does detect them when plugged into the rear jack Notification pops up asking what has been plugged in but nothing else happens. I've uninstalled and updated all my drivers with no fix. Motherboard: ROG Crosshair VIII Dark Hero.

:)

 

Realtek HD audio headphone jack

Realtek HD audio headphone jack not listed separately in device manager, headphones don't

 

Windows 10 Realtek Audio rear analog jacks not working

I just upgraded to Windows 10 from Windows 8.1, and found I wasn't getting any audio from my speakers. My Realktek HD Audio manager can detect my analog speakers hook-up in the rear panel. I can hear audio from my front panel analog jacks with my regular
speakers. I tried updating the audio drivers to 6.0.1.7541 from the Realtek site but still could not hear anything from my rear panel analog jacks (the front still work). Changing the frequency also did not work. (edit 8/2/2015) I went into sounds and checked
properties for speakers/headphones, the default device. (edit 8/7/2015) It lists the front panel l/r jack and the rear panel l/r jack, along withthe other surround sound jacks (l/r rear, center sub, l/r side).

 

Rear audio jack doesn't detect speakers, but will play sound through them if something is plugged into the front audio jack

Until today, I've been using a pair of active speakers with my PC. They've been plugged into the rear audio jack, and there's been no issue.

Today, I set-up my new pair of passive speakers (i.e. the speakers are now connected through an external amp), and plugged them into the rear audio jack. However, my system didn't recognise that any speakers were plugged in, and no sound was being produced.

So I tried plugging my old speakers back into the rear audio jack. Again, nothing detected by the system, and no sound produced.

However, here's where it gets really confusing.

If I plug the new speakers into the rear audio jack and plug the old speakers into the front audio jack, then the system will think I've connected headphones to the front jack and will play music out of the new speakers.

And if I plug the old speakers into rear and new into front, again the system thinks headphones have been connected, but will play sound out of the new speakers.

So, in short, my rear audio jack isn't detecting anything, but if I plug speakers into both the front and back audio jacks, sound plays out of the new speakers, regardless of where they're connected.

I'm using the onboard Realtek Audio Control, and have successfully updated it to the latest drivers to no benefit. I've also tried many combination of the settings in Realtek Audio Control, but it's still not detecting anything when plugged into the rear
audio jack.

The motherboard is a ASUS Prime Z370-P, and the OS is Windows 10.