Removal of audio loopback cable does not produce error.

[Comark Corp]

Hello,
I have just noticed that when I remove the audio loopback cable, the test does not fail. Using ver. 5.1 build 1014.
The sine wave looks as expected and distortion hovers between .5% and 1.5%. I then tried shorting with a length of bare wire first the input, and then the output to ground - still the test passed. I then disabled the on-board audio and installed a Turtle Beach Riviera PCI sound card and the same results were observed. Hooking a speaker up to the output, the sound of the sine wave is as expected, but it appears like the test does nothing with regards to monitoring the line-in signal. I verified that build 1011 as well as 5.0 build 1001 behaves the same way.

In fact, the only way I could get a failure is by playing a .wav audio file while BurnInTest was running. I figure I must be doing something wrong.

[Ian (PassMark)]

The loopback testing involves connecting the audio out and line in plugs. BurnInTest then plays a sine wave out the audio out and measures the input on the microphone in. If you remove the audio loopback plug and a sine wave is still detected on the microphone in then I would have to suspect that this is some type of mixer setting issue or a hardware fault. I did try a multitude of settings with a sound card here but was unable to reproduce this behaviour. Is the problem isolated to a single system or system type?

Regards,
Ian

[Comark Corp]

Thanks Ian. It appeared to be the way I was installing the driver. Instead of using the setup installation that came with the product(s) I installed the drivers through the device manager. Apparently, this defaulted the devices to 6 ch. speaker operation instead of line in, Mic, and line out. While it would be nice if BurnInTest could detect this and report an error, the fault is mine.

As a side note, is there any way to test from speaker out to line-in, instead of the microphone input?


Thanks again

[Ian (PassMark)]

We will add to our list of future features to check that Line in is in fact line in and has not been configured as speaker out channel. For now we will just update the BurnInTest help file.

BurnInTest uses the 'first' waveform-audio capable input port for the audio in. This will be the Audio, Sound recording, Default device (the input device can be changed based on the options availble in the Audio Sound recording list, Control panel -> Sounds and audio devices -> Audio tab -> Sound recording, Default device).
E.g. on my PC the list contains:
"Realtek HD Audio rear input"
"Realtek HD Front Green Jack"
"Realtek HD Front Pink Jack"
Where "Realtek HD Audio rear input" is actually Line-in (and not the Microphone).


Regards,
Ian