# Sound Blaster Live Cal with Windows 7



## SamSpade (Jun 3, 2010)

OK, I give up. I have spent hours trying to calibrate my Sound Blaster Live 24 bit USB external card and I can't get past one problem. I have made numerous searches on this forum, and read numerous discussions. But, I can't find the solution to this problem.

In a nutshell, during the Soundcard Calibration, I can't get the amplitude of the Right Channel to be close to the amplitude of the Output. 

When I use the 1 kHz test tone, I get -3dB for the output amplitude (when the Sweep Level is set to -6.0dB), but no matter what I try, the highest I can get the Right Channel to read is -11dB. The amplitude of the Right Channel moves up and down as I: 1. Change the speaker volume control of the card; and 2. Move the slider control of the volume of the speaker on the Mixer. But, when either or both control are at their max, the level is still just -11dB.

The amplitude of the Output changes as I vary the Sweep Level. Also, as I change the Sweep level of the input, the Right Channel amplitude changes correspondingly. (I can't find any other control for changing the Output amplitude.)

The card seems to be working correctly. I put the output of the card on my scope and read 1 volt p-to-p at 1 kHz when the volume is at a max. Changing the speaker volume control and moving the slider in the mixer reduces the amplitude of the sine wave I see on the scope. 

B/T/W, I have downloaded the current Windows 7 driver for the SB Live card.

Any suggestions would be greatly appreciated.


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## JohnM (Apr 11, 2006)

That will work just fine, the level difference will not be a problem. I recall occasional inexplicable level problems with the card back when I was last using it, but that's a couple of years ago now. There's also a chapter on that card at the bottom of the REW help which goes through the settings, but again it is from a couple of years ago.


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## SamSpade (Jun 3, 2010)

Thank you for the information.

My concern is I get an error message during calibration reading: "The highest level in the measurement is just -47.0dBFS. This is much lower than it should be ...."

Should I just ignore the error message?

If I do ignore the message, the frequency response looks good. the -3dB points are at 4.4Hz and 21.8KHz. It is only down by 1dB from about 7Hz to about 23kHz. However, I don't know how to interpret the phase vs frequency response. At the bottom of the chart is says: "1/48 -180deg." From 2 Hz to 50 Hz, the graph slopes up from -480 to -180 deg. The graph has a step function at about 12 KHz where it moves up to 180 deg and stays flat to 24 k Hz. What is that telling me?

Thanks for your help.


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## JohnM (Apr 11, 2006)

The -47dB FS is odd, what sweep level was that with? Didn't you say you were getting -11dB with a -6dB sweep?

Re the phase, a screenshot would make interpretation easier but sounds like the soundcard inverts hence the 180 degree shift. 180 and -180 are the same point as phase is cyclic, if you use the controls to unwrap the phase you'll see a continuous line without discontinuities at the -180/180 phase wrap points. There is a check box on the soundcard settings page to allow for soundcard inversion.


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## SamSpade (Jun 3, 2010)

Here is a screenshot of the calibration graph of my SB Live! external soundcard:









I am concerned about several issues that occured during this calibration: 

1. When I use the 1 kHz test tone, I get -3dB for the output amplitude (when the Sweep Level is set to -6.0dB), but no matter what I try, the highest I can get the Right Channel to read is -11dB.

2. I get an error message during calibration reading: "The highest level in the measurement is just -47.0dBFS. This is much lower than it should be ...."

3. Why do I get a phase shift mid-way through my calibration?

Thanks for your help.


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## JohnM (Apr 11, 2006)

Per the previous post, it is not a phase shift. Phase is cyclic, -180 degrees phase = 180 degrees phase, the tiniest shift from one can take you to the other. Try using the SPL & Phase graph controls and selecting "unwrap phase", which just lets phase increase/decrease rather than wrapping it to +180/-180. The 180 degree phase shift is due to the soundcard inverting its input (you'll be able to see that more clearly if you look at the scope plot), check the "invert" box below the soundcard input channel selection on the soundcard settings to fix that and get back to zero phase.

After you have made the calibration measurement what is the value shown for "Actual rms at 1kHz" in the measurement comments?


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