That's what I assume, but it looks a lot like Jim's measurements. I checked my sound settings and the speakers were set to small. There was no crossover setting so it just cutoff at an unknown frequency. I set the speakers to large and here is a before and after measurement. Thanks Jim.
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My 2ct are with XRK971. A loopback test with the microphone amp input on the amp output (reduced by 30 to 40dB) should reveal that.
Now you could also change your original post wording to:
"Unexplained low frequency measurement mystery Solved"
That still won't stop people from posting other "mystery explanation" theories, but might alert others to the potential of what normally invisible control panel settings can do, without reading through the eventual denouemont ;^).
Well, I was slow I admit. What drivers do you use? Often Asio4all gives better results than the standard Windows driver.
Hopefully, by now everyone knows how to configure Windows to not damage audio playback. By default Windows does real time ASRC on all audio playback, not a good thing.
Only using using ASIO, along with keeping Windows from using the ASIO sound device as a system sound device, can prevent the damage from happening.
Only using using ASIO, along with keeping Windows from using the ASIO sound device as a system sound device, can prevent the damage from happening.
Shhh, that is the Illuminati control frequency...
Actually you could just stick SPL meter into the nearfield.
And just how close IS the nearfield? Yeah by definition when the SPL doesn't change as you move the mic slightly. But IIRC Mark Gander wrote an AES paper where he had some rule of thumb-1/10 the wavelength or something...