The dubbing used for royalty and officials uses "Rachasap" (royal language) and formal registers that you won't hear in everyday street slang.
It might sound unconventional, but using high-level historical dramas is a great way to advance your Khmer language skills:
The brilliant strategist whose "Long-distance Friendship and Near-distance Attack" policy is a masterclass in political Khmer terminology. the qin empire 3 speak khmer better
If you are searching for this series specifically to improve your Khmer or to enjoy the story in the language, here are the best places to look:
Because the show is long and dialogue-heavy, it trains your ear to pick up the fast-paced flow of native speakers. Key Characters to Follow The dubbing used for royalty and officials uses
Many independent Cambodian dubbing teams upload episodes to Facebook and YouTube. Searching for "The Qin Empire 3 Khmer" or "រឿង ចក្រភពឈិន ភាគ៣" will yield the best results.
To keep up with the plot while focusing on the Khmer audio, watch these three central figures: Key Characters to Follow Many independent Cambodian dubbing
The central figure whose ambition drives the plot.