Wierd leading curve

[xenofon]

Hi,

why do i see this strange beginning of the curve. I checked all input and outputdevices to be correct. Windows and ASUS Xonar drivers seem ok too. I have tried 2 different soundcards.
Its a 500-20.000Hz sweep on a tweeter with a 6dB highpass filter. Same if i measure 10-20.000Hz - This hook at the beginning is always showing.

My guess is a latency or buffer issue in the first second of measurement.

 

[John Mulcahy]

Don't know, post some mdat files of the 500 - 20k and 10 - 20k measurements and I'll take a look.

 

[xenofon]

I have prepared a file, here it is

 

[John Mulcahy]

Looks fine to me, if you are running an older version of REW worth updating to the current beta - could be seeing a bug that was fixed in 5.20 beta 6 (Fractional octave smoothing of log spaced data could produce incorrect values at the start of the plot). The unsmoothed response is unusually noisy in appearance, by the way.

 

[xenofon]

Thank you. I will try the beta.

Works fine now.
Thanks allot.

Err, the measurements have'nt been done in a lab, rather in my livingroom. Quick and dirty measurements - coughcough. The noise its the fault of the mascot sitting on the speaker

 

[John Mulcahy]