# Sound card calibration issue



## moreira85 (Jul 10, 2008)

I read through all the STick threads and I think I am doing this correctly. I am trying to calibrate the sound card. I do not have anything hooked up, just a 3.5 to RCA adapter going into line and line out with a loop back on the right channel. I ran the measure in calibration and it looks like I am getting no audio on line in?
I am getting numbers on the left and right channels but no bar graphs?
I would post a pic if I could figure out how to print screen on here.
I am getting audio with bars in line out -12, but for line in I am getting -60s for both L and R with no bars. The Left and Right input are giving me identical numbers.
I have Line in enabled in my volume control as well.


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## moreira85 (Jul 10, 2008)

I just figured it out. There is thread on here named "Thick person about to cry". This thread is very very helpful for anyone starting out and is way better than the sticky threads. It walks you right through it. Problem is in my computers audio control I had to mute line in and go into Recording control and enable it there. How can post my graph pics?
I WAS ABLE TO MATCH THE RIGHT LINE IN WITH THE OUTPUT LEVEL, HOWEVER I AM GETTING A READING ON THE LEFT LINE IN WHEN ITS NOT EVEN HOOKED UP?????????


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## laser188139 (Sep 19, 2009)

I'm glad you got that worked out. The Please Read: Posting A Graph thread walks you through uploading and managing attachments. 

Bill


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## moreira85 (Jul 10, 2008)

Thanks, what would make me get feedback on the L channel during sound card calibration when only the R is plugged in.


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## moreira85 (Jul 10, 2008)

Here is the sound calibration graph below. Thoughts? Doesnt look smooth.


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## moreira85 (Jul 10, 2008)

Here are my settings. I am curious as to what is going on with the L input. I have it connected through R input looped to R ouput. Why is there a reading on the bar graph for L of 36.9? I matched the R and output pretty well. Should I be concerned about this?


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## moreira85 (Jul 10, 2008)

2nd reading. ouch!!!!!!!!!


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## laser188139 (Sep 19, 2009)

You've gone from an extremely wide vertical range in your previous graph, to an extremely narrow vertical scale in your most recent. I'm not sure either is that unusual for a soundcard calibration, as there is always some noise around the measurement. When you build the soundcard, REW smooths the results to determine how to adjust for the soundcard. So your soundcard calibration file will look much smoother than what you see when it is measured. 

Your first graph may be just a little noisier than usual. I'm still looking but I don't seem to have saved any of my images for comparison. If you expand the vertical scale in your last graph slightly, you will get a better idea of the min-to-max variation. Overall, the median looks pretty smooth to my eye.

You can control the scale either by magnifying, in the upper left corner, or entering values directly with the Limits icon in the upper right.

Bill


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## moreira85 (Jul 10, 2008)

They r both pretty much same graph. I just scrolled in with the mouse to get a closer view. Just not sure why calibration isn't flat like others.R u saying once I save the file it will account for this and look smoother?


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## JohnM (Apr 11, 2006)

The signal on the left input is a problem and is the cause of the bad calibration result. Make sure that there are no soundcard effects of any sort active.


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## moreira85 (Jul 10, 2008)

I am pretty sure I have checked mute on all except line in on recording .


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## moreira85 (Jul 10, 2008)

So what should b active ?


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## moreira85 (Jul 10, 2008)

I was connected to the internet and AVast antivirus was active. Anything else that may have caused the feedback in left channel?


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## laser188139 (Sep 19, 2009)

Your probably going to have to post the screens of the SoundMAX control itself to get any specific help. It appears there are different Control Panel applets for different varieties of SoundMAX cards. One user was eventually able to find a monitoring option that was causing his problem. 

Bill


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## moreira85 (Jul 10, 2008)

I went into sound max and clicked default for speakers and it switched them to stereo instead of headphones. Also I played with the volume control for playback and recording with playback volume on left and recording volume on right. Here my new settings and graph. We are making progress here. How does the level look?


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## moreira85 (Jul 10, 2008)

I know its tough to read but the input volume reads .11 is this okay?


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## JohnM (Apr 11, 2006)

Looks fine, ready to move on


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## moreira85 (Jul 10, 2008)

Thanks! I will be moving onto the next step. Quick question, In order to get smooth curve that I established I had to turn the playback volume all the way up and move the recording playback up 1/3 of the way and the result was great. After I completed the calibration it says to click "Finish". When I click finish the volume meter on the recording playback moves back down to its original setting before I moved it 1/3 of the way up. Is this normal?


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## JohnM (Apr 11, 2006)

Yes, soundcard calibration is typically carried out at higher volume settings than measurements so the adjustments made during the cal process are treated as temporary and the original settings are restored at the end.


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## moreira85 (Jul 10, 2008)

So when I set the right channel to be no bigger than a 3db difference from the ouput it is okay if after the caliration it becomes more than a 3 db difference?


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## laser188139 (Sep 19, 2009)

Before taking your first measurements, you will want to go through the Check Levels procedure and adjust the output and input levels. So you still want the input level to be not too much lower than the output level. 

It appears you are using Windows XP. It may be that, if you check the Control Input Volume and Control Output Volume boxes under Preferences -> Soundcard, you can use REW to adjust the volumes and remember the settings for you, from session to session. This could make it easier to return to your REW configuration, regardless of what else you do with your computer volume settings between sessions.

Bill


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## moreira85 (Jul 10, 2008)

Sweet thanks. I will try it. Can't wait to take first measurements!


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## moreira85 (Jul 10, 2008)

what do Iabout radio shack correction values ?


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## laser188139 (Sep 19, 2009)

If you are asking about using the Radio Shack meter to perform the Calibrate SPL step, i.e., to set the value that REW displays when a given sound level is detected, don't worry about any correction values. If you are concerned, perform the Calibrate SPL step using the main speaker calibration signal, as this avoids the low and high regions where corrections might be needed.

If you are using a Radio Shack meter as your microphone, generic calibration files for different models are available on the REW download page. 

Bill


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## moreira85 (Jul 10, 2008)

So I can do measurements without correction values, and perhaps add them in later? I am using radio shack meter as Mic as well.


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## laser188139 (Sep 19, 2009)

If you are using the Radio Shack meter as your microphone, you download the appropriate generic calibration file and point to it as your mic calibration file. The process for pointing to the downloaded file under Preferences -> Mic/Meter in REW v5 is very similar to that under v4. 

Bill


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## moreira85 (Jul 10, 2008)

*%##$$*

I set everything up tonight to start taking measurements. I did the sound card calibration successfully and was able to get a 3db differ between output and R input channel and saved the calibration. I then was ready for the next step of checking the levels.
I set everything up as follows. 
Radio shack meter RCA > R RCA/3.5mm jack line in.
Line out R RCA 3.5 mm jack > splitter R and L Aux on reciever.

I ran the check levels and made sure the ouput was giving me a 75db reading on spl meter. 
When I looked at left and right input bars both of them are getting a signal instead of just the right one.
ARRRRRRRRRgh.
Not sure why I am getting feedback on the left channel.


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## moreira85 (Jul 10, 2008)

*UPdate*

I was able to run some measurements. During the check levels I had to play with the playback and recording volume controls. I had to put the ouput volume to the max a reading of 1 on the ouput volume. In order to get only the right input channel without the left I had to set recording volume so that the Right input volume was reading 22 while the instructions aim for between 12-24 with 18 being ideal. This means the input volume was set well below the output. the ouput was set to about 12 and R input 22. When I run the right input at 22 I get no feedback on the left channel, if I try to go to 18 I get some feedback on the L channel. I calibrated the SPL meter and then ran a test. It seems as though during the test the Left input did not play which is what I was hoping for.

What are your thoughts? Am I good to use this program. Here are the results of the sweep.
Keep in mind I did not use correction file yet for my radio shack mic. I just wanted to be sure the test ran okay. Next I am going to go back and upload the correction file and run the test again.

Sub only


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## moreira85 (Jul 10, 2008)

sub + mains


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## laser188139 (Sep 19, 2009)

It would be easier to understand your graphs if you followed the posting recommendation to use 45dB-105dB for the vertical scale. As best as I can determine with the graph squished at the bottom, the graphs look reasonable. 

The Radio Shack meters are not consistent below about 20Hz -- one reason why the recommendation is to graph the sub starting at 15Hz. You might as well not display the lower regions, as it is a mistake to think the information there is real with your mic.

There is no reason to redo the measurements. With REW v5, you can associate the mic calibration file with the measurement later and save the measurement again, and it will remember to load it again the next time.

It is curious why, on your soundcard, you are seeing signal on the left input channel when nothing is connected. As you tell REW which channel to monitor, this alone should not invalidate your measure. The concern is that the soundcard software is doing something else, too, as a result of whatever option is causing this. 

Bill


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## moreira85 (Jul 10, 2008)

I reshaped the vert/horizintal axis. Looks pretty good. Seems as though my gain may need turning down a tad?? How do I get the software to assign filter settings for my BFD?


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