# Calibrating Realtek HD Audio on Windows 7



## Rairun

I think I'm giving up using Emu sound card for REW, there is a problem with the sound card calibration.
Now i try to use onboard audio on my motherboard (Realtek High Definition Audio). I've attached Realtek calibration result. Do you think it's normal?
(Btw, I'm on Windows 7.)


----------



## JohnM

Looks fine, though from the approx 180 degree phase value the card inverts its inputs so you should check the box in the REW soundcard preferences to invert the input.


----------



## Rairun

So, what did it change?


----------



## Rairun

Btw, does it look ok?:R


----------



## JohnM

Connection sketch is OK. What changed on the cal is the phase, which is now close to zero as it should be (you need to change or shift the phase axis setting to see the phase trace, it is off the top of the plot).


----------



## Rairun

How about my Windows settings?


----------



## Kenneth R.

i just want to say that you are awesome with your diagrams. very thorough! it looks good to me


----------



## JohnM

Windows settings are fine also, but if they were not the soundcard cal would not have delivered the correct result. Going through the soundcard calibration is as much about verifying everything is set up correctly as it is about correcting for the soundcard's response.


----------



## Rairun

Kenneth R. said:


> i just want to say that you are awesome with your diagrams. very thorough! it looks good to me


Hehe, thank you:bigsmile:.



JohnM said:


> Windows settings are fine also, but if they were not the soundcard cal would not have delivered the correct result. Going through the soundcard calibration is as much about verifying everything is set up correctly as it is about correcting for the soundcard's response.


Thanks very much!


----------



## Rairun

Do i have to make SPL calibration to measure the room? Because I don't have an SPL meter. I just want to see how my room response is with and without acoustic treatment. Here i just made a quick measurement with ECM8000. Does it look valid?


----------



## laser188139

You don't have to use an SPL meter to calibrate the actual SPL level. You can just set the volume adequately high and calibrate REW by saying that whatever level you have at that moment is 75dB. 

In your SPL graph, if you follow the advice in the Getting Graphs Ready to Post thread to set the vertical dimension to 45dB-105dB, it will be more informative. Also, as said there, for full range graphs, 1/3 or 1/6-octave smoothing is beneficial.

Bill


----------



## Rairun

Thank you.
For now i measure with "Use Loopback as Timing Reference" option enabled. Do you think i should continue using that method or prefer the standard method, which you calibrate the sound card once and load the calibration file?
Btw, I'd like to have some more help:
I want use REW with the purpose of demonstrating some results of the acoustic treatment in my home studio. That's for the school I'm trying to get into. First, i need to measure the entire frequency range with and without the acoustic treatment. Second, i need the waterfall plot of the low frequencies (20-200 Hz or higher? I don't know) with and without the acoustic treatment. I'm not into EQing etc.
Can you tell me the things i need to do step by step? I don't want to struggle with the buttons and features that don't concern me. (I've already been reading another measuring software's manual for hours, my mind went blank:coocoo.


----------



## laser188139

With REW v5, you need to calibrate the soundcard regardless of whether you use the left channel for timing. It's easy to do, and you only need to do it once and save the soundcard calibration file. 

You need to use the left channel for timing only if you need to compare multiple speakers using an absolute time reference, or if you are trying to verify distance/timing settings to each speaker. 

As far as what you want to look at for acoustic treatments, what little I know I have gleaned from Home Audio Acoustics forum. You might search there for REW and look for comments about waterfall and RT60, in particular about why RT60 may not be a valid measure in a home studio, while it is meaningful for large auditoriums. So far, I've personally only played with positioning and analyzing where reflections are occurring; I've not yet installed any deliberate acoustic treatments. 

Bill


----------



## CZ Eddie

Rairun, thanks for the great screenshots. I was going nuts trying to calibrate my soundcard, until I found this thread. :T

Just for reference, here are the results for my onboard Realtek High Definition soundcard on a Gigabyte motherboard.
And also a screenshot of REW settings, since that was the only thing missing in this thread. 

Btw, my cable connections were the same layout as yours. Just different equipment.


----------



## Rairun

I'm glad you benefit from the topic:wave:


----------

