When I plug in a microphone or even when using the built-in mic, the volume level is extremely low, to the point that the other party has to turn the volume way up. I've installed the latest Realtek drivers, enabled +30db boost and must turn on noise reduction. If I don't turn on noise reduction, the amount of static is incredible. I'm using Window's Sound Recorder for my testing.
Is this a fault of this model or do I just have a bad sound chip? Hardware BIOS diagnostics passes but the volume is concerning as I don't have this problem with my Thinkpad. Now I'm wondering if I should just return the laptop.
I am not aware of this being a known problem with the XPS L502x -- meaning that i don't recall seeing any other posts about the issue. I keep notes on mic issues and don't see any entries re this model.
There is a mic trouble shooter here
and also one in Dell's PC Checkup diagnostic tool.
There is also one in Dell Diagnostics audio tests if you have those tests. It is the best diagnostic because it runs independently of Winows and its drivers.