DisplayLink Forum - View Single Post - Very strange: sound frequency response changes through DisplayLink

udippel · 03-18-2019, 03:06 PM

My ears didn't fail me.
I found the reason: In Pulse Audio Volume Control I happened to notice that the USB 3.0 Pro Dock Sound drain was set to Analog Duplex in Configuration. So it was D/A-converted for the headphone socket, and re-converted D/A to be sent to the monitor via DP. The very moment I set it to Digital Output (S/PDIF) it was okay.

As an aside, though solved here, this still looks like a hardware circuit design failure through the analog signal path, since any proper analog circuitry will not effect the frequency response audibly through this type of conversion.

03-18-2019, 03:06 PM	#2
udippel Junior Member Join Date: Mar 2019 Posts: 14	My ears didn't fail me. I found the reason: In Pulse Audio Volume Control I happened to notice that the USB 3.0 Pro Dock Sound drain was set to Analog Duplex in Configuration. So it was D/A-converted for the headphone socket, and re-converted D/A to be sent to the monitor via DP. The very moment I set it to Digital Output (S/PDIF) it was okay. As an aside, though solved here, this still looks like a hardware circuit design failure through the analog signal path, since any proper analog circuitry will not effect the frequency response audibly through this type of conversion.