Do I need any extra drivers for the Realtek waves maxx audio on my Dell XPS 17?

I have found something. There are indeed drivers on the Realtek website. I think they work for all or many of their sound cards. I have a wifi card with a Realtek chip in it, and I had to get something from their website to get it to even work... let me tell you, the native Linux support for Realtek stuff is terrible.

Anyway, the first thing you want to do is download their "Audio Codec Drivers" (Misleadingly named, I believe) from their website (direct link to the page you want.) Scroll all the way down to the bottom, look under the section labeled "Unix (Linux)" and click on one of the links next to "Linux driver (3.0)". Any link will work but you probably want the one that says "US1" or "US2".

Before you do any of this, make sure that the build-essential package is installed.

The next steps: After each command, press the Enter key.

1. Open your trusty Terminal and "cd" to the directory where you have downloaded the .tar.bz2 file. For example, if you put it on your desktop, you want to type cd ~/Desktop, or if, say, you put it in your Downloads folder in your Home directory you want to type cd ~/Downloads.
2. Then you want to extract it with tar -xvf LinuxPkg_5.17rc13.tar.bz2.
3. "cd" into the directory it creates with cd ./realtek-linux-audiopack-5.17/.
4. Run the automatic installer script with sudo ./install. Type your password and press enter.
5. Now, according to the documentation, everything should run correctly with your sound after you reboot, but just be aware that everything will be muted by default. You can unmute things with your sound management thing on your desktop, but they recommend using the alsamixer command (and I also find it to be a very handy utility, especially for fancy sound cards).

I hope that this procedure gets things working for you.

The now current 5.18 version install introduced a very small bug due to different directory naming which is very easy to correct.

If you run it, it will display errors. So what to do ?

Again, make sure that the build-essential package is installed.
Delete the directory Rt-Linux-HDaudio-5.18 (just to be shure) and Start again from scratch

1. Open your trusty Terminal and "cd" to the directory where you have downloaded the .tar.bz2 file. For example, if you put it on your desktop, you want to type cd ~/Desktop, or if, say, you put it in your Downloads folder in your Home directory you want to type cd ~/Downloads.
2. Then you want to extract it with tar -xvf LinuxPkg_5.18.tar.bz2.
3. "cd" into the directory it creates with cd ./Rt-Linux-HDaudio-5.18.
4. open the install script in an editor
5. change line 1 from #!/bin/sh to #!/bin/bash (just to be shure)
6. change line 18 from cd alsa-driver-RTv5.18 to cd alsa-driver-RTv5.18/alsa
7. Save it and run the automatic installer script with sudo ./install. Type your password and press enter.
8. Now, according to the documentation, everything should run correctly with your sound after you reboot, but just be aware that everything will be muted by default. You can unmute things with your sound management thing on your desktop, but they recommend using the alsamixer command.

(note: I have unshamingly brutally copied >80% of this how-to from @searchfgold6789, except for some details, my apologies for that)