Wobbly frequency response

[AdamFrisen]

Hi,
I measured frequency response for preamp/headphone amp using REW and is wondering what could be cause of this.

XLR in and out:



Not very flat response.
Measuring unbalanced in/out shows even more:

 

[radardoug]

Your measuring setup.

 

[abbey road d enfer]

Not very flat response.

What soundcard are you using?
I remember I had a souncard that was otherwise perfect for measurements (no knobs) but had this strange FR.
How is the loopback response?

 

[AdamFrisen]

What soundcard are you using?
I remember I had a souncard that was otherwise perfect for measurements (no knobs) but had this strange FR.
How is the loopback response?

I use Focusrite Clarette+ 2Pre.

It was my test setup as radardoug mentioned (thanks for that).

I calibrated it in loopback but forgot I changed the settings in Focusrite while I was using it for Youtube (all input mixed to output).

Now I remember where I saw the similar pattern before in REW help-file.