I know the 15 R3 has the Alienware Sound Center..
The past Alienware's like the 15 R2 and 17 R3 had speakers by Klpish.. they went cheap and got rid of those and the Creative Sound Blaster Core 3D from the laptops past those revisions.
I just got mine back from the service center. Motherboard and heat sink got replaced along with Windows being re-installed. AWCC was not working when I got it, but sound was working.
I wound up installing AWCC from the Microsoft Store, along with all the add-ons like OC and FX. Had to do it twice because it failed the first time. End result is I have all the presets and controls for my audio after the second install and a restart.
Give it a try. It might work.