TOPIC:

I have two laptops, both Lenovo, one running Windows 8.1 and one running Windows 10. I am going through all of the steps in the guide here with my new UMIK-1.

On the Windows 10 laptop, the REW SPL meter only reads 27. I have a Radio Shack SPL meter and got the pink noise up to 75db, but the REW SPL meter didn't budge from 27.

On the Windows 8.1 laptop, it seems to work fine.

Any ideas of what I should try to get it working on the Windows 10 laptop? I've rebooted, unplugged and replugged the UMIK, and switched between the REW beta and the latest stable release.

If there is some troubleshooting guide or something like that I may have overlooked, please point me in the right direction. Or should I open a support case?

Thanks in advance for your suggestions and ideas!

@ patja

This is very odd.. How about providing us with few screenshots of your setup under REW?
Maybe a good first start?

DevTeam

I encountered the same problem and believe that I have figured out the cause: a mismatch between the audio format that REW requires and the format that Windows is supplying.

The windows version of REW only accepts 16-bit input from the microphone. The 24 bit format won't work with the Windows version of REW (but it's fine for the Linux and Mac versions).

The Windows Audio Input device on my (brand new) HP laptop only supports "2 channel, 24 bit, 48000 Hz, (DVD quality)" format. To work with REW, it needs to be "2 channel, 16 bit, 44100 Hz, (CD quality)".

Because the Windows version of REW is expecting a 16 bit reading from the microphone --- but is getting a 24 bit value --- the reading is interpreted incorrectly. In my case the reading was around 27 dB, just like you reported.

If you can set your audio input device to "2 channel, 16 bit, 44100 Hz, (CD quality)" you should be fine.

I'm going to have to use a different PC.

After posting about this problem on the REW support forum at AV Nirvana ( www.avnirvana.com/threads/rew-incompatib...cs.10552/#post-79747 ), John Mulcahy, the author of REW, weighed in.

He said:
REW does not require 16-bit data. The Windows JavaSound implementation will only pass 16-bit data to REW but that is independent of the data format of the interface. All UMIK-1 have 24-bit 48 kHz as their default format, for example, the default format choices are governed by the device, not the OS. The problems you are encountering must lie elsewhere. A common feature of newer Windows builds is to apply noise cancellation by default on any mic input that provides stereo data, that can usually be prevented by disabling all enhancements on the Windows audio properties for the mic input, on the Enhancements or Advanced tabs. Some laptops also install other audio processing applications, such as Waves MaxxAudio, which may have their own control panels.

I haven't found the audio enhancements that John suggests might be the cause of the problem. From what I can see, I had already disabled all such enhancements. But John is an authority so that I'll keep looking. 
 

After following John Mulcahey's suggestion (see above), I was able to find and fix the problem. Here's what it turned out to be.

I checked again to see if there was something that was affecting the audio that wasn't showing up in the "Settings" menus on my PC. It turned out there was. 

My HP laptop comes with an application called "HP Audio Center". I hadn't ever run it, nor was it evident from the "Settings" menu. But when I ran it I came across this screen:
 

When I set the noise cancellation in "HP Audio Center" to "off", the UMIK-1 started working correctly (in that the REW SPL meter was showing correct values). Problem solved.

For the benefit of others who may get tripped up by something similar, it's worth noting that the HP Audio Center doesn't show itself in the "Settings" menus. Here's the Sound properties screen:
 

And, when one selects the "Advanced" choice under "Enhance audio", it's not evident there either:
 

I was misled by thinking that, since I couldn't change the settings from "2 channel, 24 bit, 48000 Hz, (DVD quality)" format, that must have been the cause of the problem. It wasn't. All that was needed was to find "HP Audio Center" and change some settings there.

I'm grateful to John Mulcahey for pointing out the cause of the problem --- and for writing REW and making it available to all.