Siblings in Revel's Performa4 series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (55Hz vs 54Hz). |
| Amplifier needs | evenly matched | Similar sensitivity (86dB vs 85dB) - both want much the same power. |
| Size | depends | Revel Performa4 M145 is easier to place; Revel Performa4 C245 is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive Center Channel against a Passive Bookshelf - a different job rather than a better one. |
| Price | B | Revel Performa4 M145 is cheaper - $1,999 against $3,998, about 50% less; arguably a different class. |
A Revel Performa4 C245 B Revel Performa4 M145
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. In a large or open-plan room, Revel Performa4 C245 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Revel Performa4 M145 is the easier speaker to get right. Think about the whole system, not just the speakers: the roughly $1,999 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.