Strange calibration measurement - need help

[Dragon777]

Hello,

I am using an old Soundblaster live soundcard (the one from 1999 that came with the live-drive) and tried to calibrate it through REW. Using the live-drive front aux 2 gave me the feedback loop so I switched to the regular back Mic in. The measurement result is very strange as seen in the picture.

A measurement with the mic without calibration looks quite similar. From 400Hz on, its not a line anymore, but this strange stuff.

What went wrong? Can anyone help?

Thanks in advance!
D

[brucek]

so I switched to the regular back Mic in

You must use the line-in and not a mic-in for REW. Too much gain, too much distortion, poor response, etc.

A Radio Shack meter outputs line-level........

brucek

[Dragon777]

Hello,

but I need to use the mic-in for the regular measurement through the measuring-microphone?

When I do this, this is what I get. Looks equally strange.

Best regards
D

[brucek]

but I need to use the mic-in for the regular measurement through the measuring-microphone?

Can you explain what you mean by this?

When I do this, this is what I get. Looks equally strange.

Use the standard vertical scale of 45dB-105dB and turn on 1/3 octave smoothing feature to remove normal comb filtering.

brucek

[Dragon777]

Hi,

ok, smoothing the curve works. So you say the graph is perfectly ok for not being smoothed at all?

Regards
D

[brucek]

So you say the graph is perfectly ok for not being smoothed at all?

Can't really say, because I don't know the type of microphone/meter you're using, and you haven't shown a correct soundcard calibration using a line input.

brucek