Here’s a sound/quality comparison between the built-in speakers of your OPPO Reno 14 Pro and the Monsoon MH‑500 Flat Panel 2.1 PC Speakers (the classic Monsoon MH-500 setup you used to have).

These are very different kinds of sound sources, so I’ll look at them in their real use contexts rather than just raw numbers.

🎧 OPPO Reno 14 Pro (built-in speakers)

Pros

Stereo speakers with good loudness for a phone

Relatively clear mids and highs for media

Strong separation for videos/gaming

Great for its class (flagship smartphone sound)

Cons

Small drivers → limited bass

Soundstage is narrow (phone speakers always are)

Can get “thin” at higher volumes

Speaker Score: 8.5 / 10

(This reflects good loudness and clarity in a smartphone form factor.)

🔊 Monsoon MH-500 Series Speakers (Desktop System)

What they were

Small planar/focused desktop speakers with a subwoofer (when complete) that were popular as PC or small-room speakers in the 1990s/early 2000s.

Pros

Larger physical drivers than a phone

With the subwoofer attached → deeper, richer bass than phone speakers

Planar-style satellites give very positional, immersive sound on a desk setup

Retains good clarity; often better “room-filling” experience than cheap PC speakers.

Cons

Still not high-fidelity hi-fi — budget multimedia quality

Sound tends to be directional and small without sub

Bass & power limited compared to Hi-Fi bookshelf systems

Some units are old enough they have reliability issues (e.g., volume puck problems, buzzing noise) because of age.

Speaker Score: ~7.5 / 10 (for desktop PC use with a subwoofer)

— If used without the subwoofer, more like 6.5–7/10.

(http://www.autoadmit.com/thread.php?thread_id=5832181&forum_id=2:#49654006)