Weird and different ETC diagrams on PC and Notebook

[bigumbrella]

Hi,

I have trouble getting a correct ETC-Diagram on my Workstation (Windows 10 64bit).

I'm using a Focusrite Scarlett 6i6 2nd Edition and a UMIK-1. When I'm using the Scarlett and the UMIK-1 on my Notebook (also Windows 10 64bit) everything looks fine, but on my PC the ETC seems to be weird / coruppted. I'm using the same settings on both machines (Bitrate, Mixer settings, REW settings etc.), did tests with Java Driver and Asio - no success. I've replaced nearly every component on my Workstation, reinstalled Windows - likewise without success.

On my Notebook:


On my PC / Workstation:


Or sometimes on my PC:


What could be the root cause for this problem? I don't understand, why "All SPL" for example is nearly identical, but ETC is totally different.

Mdat is included within the attachement.

Thanks in advance.

bigumbrella

 

[John Mulcahy]

The workstation impulse response looks pretty odd, with a lot of pre-ringing. That can sometimes be a symptom of sample rate conversion in the chain somewhere, though it is so different it is difficult to know what could be going on. Try with a shorter sweep to see if that makes a difference. The output device and output weren't selected for the workstation measurement, so presumably the Focusrite was the default device? It is much better to select the device and the output in REW to make sure the signal is going where you want it to.

 

[bigumbrella]

Hi John,

thank you. A faulty sample rate conversion was a thought this afternoon, because the ETC looks roughly "streched" in both ways. The UMIK-1 is specified with 48Khz/24bit and I've tried 48Khz 16 and 24bit with my audio interface without success. I will have a closer look tomorrow in regards to your hints and will post my results.

Best regards,

bigumbrella

 

[bigumbrella]

Hi John,

this seems to be a problem with a fresh installed Windows 10 (Build 1809). On older systems, which were normally upgraded, it's working. There must something went wrong, when REW respectively Java asks the OS for the adjusted sample rate and bit depth.

The only audio interface which works fine in my test scenario is the Behringer UMC204HD. And there is a difference: You have to set the sample rate and bit depth within the Behringer UMC-Tool (you can't do this in the Windows Audio Settings). On my other tested audio interfaces, like the Scarlett 6i6 2nd and the Steinberg UR44, you can only switch the sample rate within the manufactures control application. But in this case you can change the bit depth in the Windows Audio Settings. But it seems, that REW always get the default bit depth of these both interfaces, which is 24bit - even when the bit depth is set to 16bit. Maybe this causes the wrong conversion (not in relation to the UMIK-1, which is always 48Khz 24bit).

On older Windows installations, even though when upgraded to the newest version, there must be still access to get the correct data, which is no longer available on a fresh installed Windows with one of the newest Build versions. I still remember the big trouble people had with audio hard- and software when Microsoft released their October-Update last year.

On a new installed Windows I'm only able to get correct results within REW, when I'm using a mic directly connected to the audio interface and using the manufactures ASIO interface. With Java drivers or ASIO4all in combination with a UMIK-1 (not valid for the Behringer) it’s not working.

Note: On my notebook (Intel) everything works fine (Windows installed a year ago, cont. updated). For a test I've made a backup and installed the newest Build from Microsoft. Now it shows the same curious results as on my workstation (AMD).

Best regards,
bigumbrella

 

[John Mulcahy]

Bizarre. My laptop runs 1809 without issues, but it was upgraded from a previous version.

 

[bigumbrella]

Bizarre. My laptop runs 1809 without issues, but it was upgraded from a previous version.

Yes, really bizzare, and it cost me so much time. I've replaced nearly every component of my workstation. And as you said: You're running an upgraded version (like on mine), which makes the difference. It's not a trick - it's Windows