Can´t calibrate my soundcard frequency responce

[pix]

In totaly new with REW so don´t be hard on me..
I´m using a HP Envy TS Sleekbok 4 with Windows 8.1.
My soundcard is a IDT High Defiition Audio CODEC and there seems to be some sort of Beats feature installed.
I have looped the headphone output to the Mic input L to L, R to R and GND to GND

The levels seems fine, but when when calibration procedure is finished the frequency respons is totaly wrong. I have read the manuals, trying to understand. But I need help to get this right.
Could it be that Beats sound feature causing this? I have opend the Beats Audio Control Panel zeroing all the sliders, and trying to unconect it, but it makes no diference.

The sound from the soundcard works perfektly, so I figure this must be some sort of setup-problem.
I hope for some help (explained in a simple understandable way)
Best
Pix
Sweden

 

[John Mulcahy]

There are a couple of possibilities. The input may be intended only for microphones and not as a mic/line input and have EQ to allow for that. Not so common these days. Or there may be enhancements active on the output. If you open the windows Sounds dialog from the control panel, look on the playback tab, select the output you are using and then select Properties there will be a tab for any enhancements. You should be able to turn them off there.

 

[pix]

Thanks John, butI don´t have any enhacements tab in the windows Sounds dialog.

However, I fiddled around a bit and came upp with the calibration curve attached (see pix 2).
Is this curve the responce before corections?

I was´nt clear about this so I tried made a measure sweep, using the ouput to input cable (the calibration cable). This gave me the curve shown in pix 1, which is very flat 20-20KHz

Is this calibration considdered ok now, to go on with the acoustic measurements?

 

[John Mulcahy]

There's a lot of response shaping in that curve, so something is applying that, but if you can't find a way to turn it off then calibrating it out is OK.