SPL Sweep measurment no signal under 100Hz

[Aqua_HeaD]

Hi!

Sorry for my poor english. I am trying to measure my car speakers with the sweep test included in the REW but I will not hear any tones below 100Hz. It seems that lower frequencies not will be measured as they should since no sound below 100Hz will be sent out from the headphone plug (output)) of my laptop . I have always used the RTA function before but I would like to try the sweep test instead. If I use the tone generator then the lower tones will be played as normal so I guess it must be some issues with the settings.

The pictures below are a test when I just had my headphones connected. I use the AUX input and my UMIK-1 when measuring in the car.

Anyone have any solution how to fix this?

 

[skid00]

You might need to turn off 'audio enhancements' in the Windows sound preferences dialog... A search might get you more background, and images to refer to.

 

[Aqua_HeaD]

Thanks. I read something about the cancellation problem in another thread. It had something to do with the microphone output if I am not wrong. I will try it.