Impedance Testing with a Laptop

[Nordo]

I've used my laptop with REW in the past for room testing, speaker placement, etc., but now I need to take some Impedance and SPL measurements of speakers for their crossover design.
The laptop has two USB (3.0) ports where I normally plug in my miniDSP UMIK-1, a HDMI port and a headphone socket.

How do I used the laptop to do the Impedance testing?
And how do I get the SPL graph under the same settings as the Impedance test?

I put up a post earlier, but realise now that I didn't explain my basic problem - the laptop.

 

[John Mulcahy]

If you laptop has a stereo line input in addition to its headphone output you could use it as is, otherwise you will need a two channel USB audio interface, ideally one with an output that can drive low impedance loads. The connections to the interface are shown in the help.

 

[Nordo]

If you laptop has a stereo line input in addition to its headphone output you could use it as is, otherwise you will need a two channel USB audio interface, ideally one with an output that can drive low impedance loads. The connections to the interface are shown in the help.

Thanks John.