Wrong parameters measured

[brunohydra]

Hello, i`m Bruno from Brazil. Here we don`t have access easily to DATS V3 and is so expensive to import, it`s my hobbie and I can`t expense all that money to study only. I saw a video about measuring TS parameters with REW (

), i made the cable and bought a USB soundcard like this:

I did everything like is on the video but after calibrate parameters, I had a graphic like this:

I`d tested with 3 different soundcards and the response is the same.
Can anyone help me with this problem?

Sorry for bad english, it`s not my native language

 

[John Mulcahy]

There are a few things that can be wrong. The most likely are a mistake in the way the jig is wired or the way it is connected to the soundcard. Perhaps you can show some images or a sketch of how you have connected everything? With that soundcard you should use Line in for the input connections and one channel of front out for the output. If things are working properly the reference cal measurement should be a flat line showing the same resistance as the reference resistor that was measured to make it.

 

[brunohydra]

Hello John, sorry for my late.

 

[John Mulcahy]

You can't use a mono jack for the output, those outputs are stereo. Front out will have left and right on it, so your jack is shorting one of them to ground.

Use the line in, not the mic in.

 

[brunohydra]

Hello John.

I`m so happy, I did the changes you said and now it works!
Thank you so much!

*Image 1 is a 6 inches speaker and image 2 is a 5 inch speaker.