Recording Stereo Mix from my computer sounds horrible.

I am using Windows 10 and using Audacity 2.0.6.
Whenever I record sounds and music from my Windows 10 computer using Stereo Mix, it sounds horrible to me. It sounds like that there is a lot of treble and hardly no bass.
My Sony Vio computer, that uses Windows XP, could record a lot better, using the Stereo Mix.
For my Windows 10 computer, I have the settings in Audacity set for: Audio Host: WASAP, Playback Device: Speakers (Realtek High Definition Audio), Recording Device: Speakers (Realtek High Definition Audio), and Recording Channels: 2 (Stereo) Recording Channels. I cannot figure out how to get Headphones (High Definition Audio) for Playback Device and Recording Device. It seems like MME sounded better than WASAP or Realtek. Windows XP had good sound quality for MME. I have not been clipping on my recordings, either.
This person on Youtube had a good tutorial on how to get a Stereo Mix on audacity for Windows 10:
https://www.youtube.com/watch?v=f-_t_ZaUqE8

How can I get a good recording sound quality in Stereo Mix for my Windows 10 computer, using Audacity?
How do I get Playback Device and Recording Device to be Headphones (High Definition Audio)? I cannot find the Headphones settings.
Does it matter if Playback Device and Recording Device is set to Headphones (High Definition Audio) or Speakers (Realtek Definition Audio)?
Which is better quality: Headphones (High Definition Audio) or Speakers (Realtek Definition Audio) for its settings?

Don’t use Stereo Mix, use [u]WASAPI (loopback)[/u]. That should give you the best quality, capturing the digital audio stream without monkeying with it.

Does it matter if Playback Device and Recording Device is set to Headphones (High Definition Audio) or Speakers (Realtek Definition Audio)?
Which is better quality: Headphones (High Definition Audio) or Speakers (Realtek Definition Audio) for its settings?

Assuming this is a laptop, the speaker setting is probably rolling-off the bass. Your internal laptop speakers can’t reproduce bass and filtering-out the bass can give more power to the sounds they can reproduce, and reduce distortion. (I don’t think those settings will affect WASAPI (loopback) but they will affect Stereo Mix.)

Thanks. I’ll give the WASAP Loop Back a try. I don’t know if my Windows 10 lab top really has a good sound card or not. The Sony Vio computer sure did have a good sound card. Hopefully I can get around this trying the WASAP Loop Back, or try adding more Bass and Treble to the song without distorting it.

Bass and Treble to the song without distorting it.

You can use the Audacity Bass and Treble or Equalizer effects after recording.

When you boost anything you can potentially push the levels into [u]clipping[/u] (distortion). The trick is to run the Amplify or Normalize effect after applying EQ (or bass & treble) but before exporting.

Amplify will default to whatever change is needed (up or down) for 0dB “maximized” (normalized) peaks. If it defaults to a positive dB change you are safe and you don’t need to apply the effect. If it defaults to a negative dB change, the peaks are currently over 0dB and can clip when you export as a “normal” audio file.