Thank's for quik answer.

I did not try, I will try it when buy splitter and write the result here.

Hi xOslyx,

Thanks for posting. Apologies that your system is not performing as expected.

According to the information provided, it would appear that the plug on the headphones could be shorting across the terminals.  Have you tried an audio splitter?

If you need additional assistance, please contact me privately. Be sure to include your personal information (name, address, telephone, email) and your computer's service tag number in your message. Thanks.

twice...

Part of problem fixed with new Realtek driver (Realtek High Definition Audio (HDA) R2.8x (8485) WHQL + Dolby).

When I plug in a headset without a microphone now, the notebook microphone works. Only the Maxaudio app think that headphones are not connected.  But you can edit the audio settings.

However, when I have a splitter I will try and write the result.

No changes with splitter. I tried installing the driver 8397 and 8485 and reinstalling the MaxxAudioPro aplication. 

The MaxxAudioPro does not detect the jack connection (splitter or headphones).

Summary:

When I plug in a headphones without a microphone (or splitter with a headphnes) now, the notebook microphone and headphones works. Only the MaxAudioPro app think that headphones are not connected.  But you can edit the audio settings, but some setting is disabled because is enabled only for headphones. 

Sound from headphones is terrible.

I've had a similar problem, the way I solved it was to install the latest MaxxAudioPro and Realtech drivers from the dell support page for my make and model, the part I nearly overlooked was the advanced settings at the bottom of the MaxxAudioPro

Make sure this pop-up is ticked so you can get this when you connect external audio devices via the combined mic/speaker jack

In my case I'm using a headset with both speakers and mic, by selecting headset (and no headphones) the laptop mic in the top of LCD bevel is deactivated and only the headset sound and mic is working as intended

the rest of the setting was done via windows control panel - sound, where the mic now shows it is enabled via the front jack

I've selected don't show this box again and while I've got my headphones (no mic) connected to the laptop it wont detect me speaking so i assume I've selected the wrong option how does one actually get that which device did you plug in box back up again?

I appear to just be bad at reading and missed using the advanced settings to open the pop up thanks for the guidance!