# REW 5.01 Beta - Soundcard Calibration Issue (dB variations)



## Appelbom (Nov 17, 2011)

Hi,

I'm a new member and just bought gear to perform room acoustic measurements, however i seem to be stuck already in the soundcard calibration phase.

HW/SW involved:

Lenovo X201 Windows 7 Enterprise Laptop
Roland UA-55 QUAD-CAPTURE with driver & control panel version 1.0.1 (loop from output 2R to input 2R with 3 meter jack to XLR cable)
REW Version 5.01 Beta

Windows Sound Setting 1:







Windows Sound Setting 2:







Roland Settings 1:







Roland Settings 2:







REW Soundcard Settings 1:







REW Soundcard Settings 2:







REW Soundcard Measurement:








I have made sure to deactivate the "Direct Monitor" button on the soundcard.

Surely the soundcard measurement is not good?? Am I doing something wrong or is my soundcard messed up?

Thanks in advance for any help or pointers!


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## EarlK (Jan 1, 2010)

Hmmmm,

Thanks for the pictures / they do help .



> I have made sure to deactivate the "Direct Monitor" button on the soundcard.


 Good, if it was active you would get signal feedback ( which would be another type of trace ) .



> Surely the soundcard measurement is not good??


It's not good . It's noisy ( those spikes ) and looks to roll-off in the low frequencies a bit before I would expect .



> Am I doing something wrong or is my soundcard messed up?


Your overall methodology ( according to your pics ) is correct . 

Before blaming the soundcard, make sure ;

> Your computers WiFi is "off" .
> Power your soundcard from the USB buss / not any included supply .
> If you used the mic input / turn off the 48v phantom power . 
> Or make your "loop-back" is from "line out to line in" ( ie ; not the mic input on the soundcard ) .




> Thanks in advance for any help or pointers!


Your welcome ! / I hope something mentioned helps :T


:sn:


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## Appelbom (Nov 17, 2011)

Yay! i think that worked!! :T :T
Being a newbie I totally didn't think about the phantom power issue...

Here is the new measurement with soundcard phantom power off:








This is "approved" right??

So excited - thanks for the help Earl! :sn:


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## EarlK (Jan 1, 2010)

That looks better :clap: / though the noise up in the HF area actually increased ( which is weird ) .

That calibration is usable , though I would try a better quality ( loop-back ) cable ( with better shielding ) to see if I could get the visible noise to settle down ( to what you see at around 1000 hz ) .

<> :sn:


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## Appelbom (Nov 17, 2011)

Many thanks Earl - I'll see if I can get a hold of a better cable (even though I just bought this one for this purpose... bought it from a Pro Musician store - 3 meter Jack to XLR "Referement Cables (made in Italy) # MCR5 HI.-Q. Microphone Cable 2X0,22 mm²" - at retail 50 $. Murr....) 

Once I get going I'm pretty sure I will post my measurement for further guiding! :heehee:

Cheers,
Lars


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