Siblings in Paradigm's Premier series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | Paradigm Premier 120B v2 digs deeper - 62Hz against 73Hz. |
| Amplifier needs | B | Paradigm 500C is more sensitive (92dB vs 90dB), so it goes louder on the same amplifier. |
| Size | depends | Paradigm Premier 120B v2 is easier to place; Paradigm 500C is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive Bookshelf against a Passive Center Channel - a different job rather than a better one. |
| Cabinet | depends | Ported vs Sealed. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
A Paradigm Premier 120B v2 B Paradigm 500C
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 73Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Paradigm 500C has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Paradigm Premier 120B v2 is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.