# Sound Card Calibration Help



## eye1 (Apr 25, 2008)

I am getting a message that I have a low signal level. Not sure where to look. I appears that I have things hooked up correctly. I am not able to adjust input volume on the settings page because it is greyed out. 

Here is what I have so far. The graphs tell me that I am getting a reading from the SPL Meter but is it strong enough?

Any Ideas what this means?


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## eye1 (Apr 25, 2008)

Here is the sound card calibration graph and the impulse graph. The would not attach to the first post.


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## eye1 (Apr 25, 2008)

Here are the missing graphs. Too big on the first attempt


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## brucek (Apr 11, 2006)

Why is there signal on both the left and right channel. You should have a short cable going from the left channel line-out to left channel line-in. The right channel should be left open.

Adjust the input level with the Windows mixer..

brucek


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## JohnM (Apr 11, 2006)

What soundcard are you using?


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## eye1 (Apr 25, 2008)

JohnM said:


> What soundcard are you using?


I am using the Soundmax Integrated digital audio from my PC
It has a plug in for a mic, output, and what appears to be the input to the far right.


I have followed the set up diagram and i am using the stereo splitters in both the line out and line in.

Does the loopback connection split the signal for calibration?

I have also disconnected everything and only used the right(red) out and connected to the right(red) line in. I still show input to both channels. Hmm. 

Could it be the sound card not splitting the channels?

Thanks


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## brucek (Apr 11, 2006)

> Could it be the sound card not splitting the channels?


Or do you perhaps have 'monitor mode' turned on?

brucek


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## eye1 (Apr 25, 2008)

brucek said:


> Or do you perhaps have 'monitor mode' turned on?
> 
> brucek


Where do I check for this? I do not see a monitor mode setting for my integrated sound.


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## brucek (Apr 11, 2006)

It would be a feature of the Soundmax Integrated application itself that would be accessed from the Control Panel.

They sometimes have a goofy name for it like "what you hear", or "mixed", etc..............

brucek


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## eye1 (Apr 25, 2008)

brucek said:


> It would be a feature of the Soundmax Integrated application itself that would be accessed from the Control Panel.
> 
> They sometimes have a goofy name for it like "what you hear", or "mixed", etc..............
> 
> brucek


Wow, that appears to be the issue. Line in was disabled. Now it is now enabled. I will give it another go.

Thanks


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## JohnM (Apr 11, 2006)

Careful - Line In should be disabled for playback, but selected for record. Worth posting screenshots of your playback and record mixer settings.

Also on your main volume control turn the Room EQ Wizard volume up full.


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## eye1 (Apr 25, 2008)

Thanks for your patience Bruce and John.

I had line in enabled for playback and record line in was enabled. This may be why I was having so much feedback.

Here are shots of my new settings. I will retry again.


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## brucek (Apr 11, 2006)

When you select the Speakers in Playback, you want to set them to Default. Then when you select their properties, you want to be sure that the Line-in is disabled. When line-in is enabled in Playback, this is the monitor feature. You want it disabled.

In the Record properties, you want the Line-in enabled of course.............

brucek


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## eye1 (Apr 25, 2008)

brucek said:


> When you select the Speakers in Playback, you want to set them to Default. Then when you select their properties, you want to be sure that the Line-in is disabled. When line-in is enabled in Playback, this is the monitor feature. You want it disabled.
> 
> In the Record properties, you want the Line-in enabled of course.............
> 
> brucek


In device usage there is no selection to Default and in properties there is no Line-in to disable.

I do not seem to be able to get there with this on-board sound card. 

I can get there with line-in for record.:wits-end:


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## JohnM (Apr 11, 2006)

If Line In does not appear in the properties of Speakers that's OK. Re-enable Speakers, in the properties for speakers check that there are no odd controls on the "custom" tab (if there is one), make sure the levels are OK on the levels tab, and select the box to "disable all enhancements" on the Enhancements tab. Also disable enhancements on the properties for Line In and make sure the levels are OK on its levels tab. 

Make sure the 3.5mm plug on your stereo splitters looks like the picture in this thread: http://www.hometheatershack.com/for...tion/10001-rew-cabling-connection-basics.html
There need to be 3 connections on the plug, there are lots of "stereo" splitters that just have a mono 3.5mm plug that is linked to 2 RCA sockets, they are no good for this purpose.


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## eye1 (Apr 25, 2008)

Thanks, I think I am making progress now. I referred to another recent thread showing a comparison of a Turtle Beach card to the Vista card. I did find the settings to get it set up with no feed back. 

I adjusted all levels on the sound card tab with good results and good graphs. When I get to the Make a measurement step and check levels I get a level is Low message.
The receiver volume is quite high and there is noticeable hum. When I turn up the receiver more I still get the Low Level message. Any Ideas on what I should try?


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## brucek (Apr 11, 2006)

Are you checking the Levels with a Subwoofer calibration signal using a subwoofer with the mains turned off?

brucek


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## eye1 (Apr 25, 2008)

brucek said:


> Are you checking the Levels with a Subwoofer calibration signal using a subwoofer with the mains turned off?
> 
> brucek


I dont think so, still using the noise from the main speaker. Its like at this point the SPL is not giving an accurate read to the line in on the sound card. I will see if I can post screen shots soon.:wits-end:


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## JohnM (Apr 11, 2006)

Just ignore the levels check on the measurement screen and see what levels you get during the measurement itself.


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## eye1 (Apr 25, 2008)

Ok, Here are screen shots of my settings and a graph. Can you see anything that is suspect to causing issues? The first step of the measurement screen runs the tone and says the level is good but when I go to measure this is the message that I get.

I will also mention that I have not been able to completely isolate the signal on the graph to one channell during the sound card calibration but the graph seems to look good.

On the playback line levels I have muted all the choices except playback volume control.:wits-end::wits-end::wits-end: 
Thanks for the help! I have too much time in to give up:bigsmile:


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## JohnM (Apr 11, 2006)

The level settings on those properties pages all look good, and it is OK to just click "OK" on the warning message about the input level from the measurement. Assuming the final measurement looks OK all you'll need to do is either turn up the volume on your system a bit to get cleaner results or use a lower scale on your SPL meter.

Difficult to understand why there is input on the right channel though, when your SPL meter is only connected to the left, correct? A photo or two of your connections might shed some light on that.


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## brucek (Apr 11, 2006)

> Difficult to understand why there is input on the right channel though, when your SPL meter is only connected to the left, correct? A photo or two of your connections might shed some light on that.


I can only think of two possibilities for that happening.

1. Using a mono connector plug when it should be a stereo plug.
2. Extremely poor crosstalk figure in the soundcard.

Have you, as a test, used the right channel as opposed to the left channel and seen if the results are the same?



> The first step of the measurement screen runs the tone and says the level is good but when I go to measure this is the message that I get


Keep in mind that the _Check Levels_ routine in the Measurement screen and the _Check Levels_ routine in the Settings screen use different values to generate the pink noise level setup test signal.

The Check Levels routine in the the Settings screen uses the fact that you have the _*Check/Set levels with Subwoofer*_ pull-down selected to generate its test noise (this a band limited signal with a low and high cut of 30Hz - 80Hz) - but then you are measuring full range up to 20000Hz in the Measurements screen. Even if you were using the Mains Full Range pink noise test signal, it has a low and high cut of 500Hz - 2000Hz. 

REW double checks and verifys that the _*end frequency*_ of the sweep that you have selected in the Measurement panel roughly matches the test signal setting (for sanity), its Check Level routine uses the end frequency as the test pink noise hi-limit cutoff. So if you had 20KHz as the end frequency to measure for your sweep, you can see how the pink noise would be different (between the two Check Levels) and as such the low level signal you're experiencing.

Long story short, use the correct test signal (subwoofer or mains) to set up the levels. If you've done this correctly and the Measurements screen Check Levels sanity test passes, don't worry about a level warning.......

brucek


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## eye1 (Apr 25, 2008)

You both have given me alot to look at and consider.

Since my settings appear to be correct and graphs look good I will disregard the low signal level by changing the SPL input meter level to get a good signal. 

I did attempt to turn the volume up to get the proper reading on the SPL meter but it was much higher than the reference 75dBL range - when the receiver was this loud I would get alot of feed back through the meter - like it was becoming a live mic whith a high pitch. 

I will let you know my results hopefully sooner than later.

I do appreciate your help and patience working through this.


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## eye1 (Apr 25, 2008)

Ok, I am back with results.

Looks like I am having success now. Here are 3 graphs for your much appreciated input on.

The first one for conversation is of simple spl meter measurements. 

The second one is to show the sound card calibration.

The third is to show F C R with SW at 80Hz X-Over

The fourth is to show FCR with SW at 50 Hz X-Over

I applied 1/3 Octave smoothing to each. Please not the reading from the SW on each graph. I did disregard the low level warning at the end of the measure because the graphs look to be good - the only thing I would ask is why am I showing at a lower dBL on the graph. The SPL was calibrated and during the measure the SPL does read from about 72 to rise quickly to touch 80dBL at the very end of the measure.

Does it look like I am on the right track with these? What would you recommend I do next? 

I thought I would isolate and run a independent measure of each the SW, L and R to help determine the optimal X-Over.


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## brucek (Apr 11, 2006)

> Does it look like I am on the right track with these? What would you recommend I do next?


You're not getting any signal from your SPL meter at all into the PC. The rising levels at either end of the spectrum is from the meter and soundcard cal files.

The soundcard calibration file looks great. That says everything is working fine with your PC. The problem is that you're not getting any input from your microphone at all. 



> I did disregard the low level warning at the end of the measure because the graphs look to be good


In this case the warning is legit. Either your meter or cable or adapter is not correct. Plug the meter into the AUX input of your receiver and sing - it's a microphone - see if it's working..

brucek


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## eye1 (Apr 25, 2008)

I now have input. There were still settings in the sound card line-in that were not correct. I had to go into the balance and turn off line 1 to 0 and line 2 to 100. At the very end of the measurements I would start to get feed back from the SPL Meter. 

Here are new jpg.s to show my success. The first one is using the 50 Hz X-Over and the 2nd is with the 80 Hz X-Over. Both are using Left Right and SW with no sound from the Center Channel. How would I isolate sound to the Center?

Looks to me that the 80 Hz X-Over has fewer nulls and eq able tops. What are your thoughts on this? How does the room look to you on the graphs? 

The Third graph is of the SW only at 50Hz and 80Hz

Next I will be on to equalizing. Would there be a typical process for the next steps you could recommend or areas I should focus on?

Thanks again for your patience. I read somewhere in these forums that most issues are operator error in not setting up something correctly.:bigsmile::bigsmile:


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## brucek (Apr 11, 2006)

Yeah, looks like you have it working good now. 



> How would I isolate sound to the Center?


The receiver should only be used in stereo (or mono) mode. Never use a sound field.
Isolating an REW sweep to a center channel is accomplished by removing a main speaker wire and substituting the center channel speaker wire and turn the balance over to that channel.

Also note that if you're using a Radio Shack meter, the full range measurements aren't accurate above ~ 3KHZ at best. See that peak at 7K - likely the meter causing it. Limit the sweeps to 3KHz. If you want to do accurate full range measurements, you need a better microphone and preamp such as the ECM8000 and XENYX802.

Another note: start all your horizontal axis' on your graphs at 15Hz (and not 2Hz)..

brucek


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