Siblings in Revel's Architectural series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 90dB) - both want much the same power. |
| Headroom | evenly matched | Similar power handling (150W vs 150W). |
| Size | depends | Revel W553L is easier to place; Revel W783 is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive In-wall against a Passive Center Channel - a different job rather than a better one. |
| Price | B | Revel W553L is cheaper - $545 against $1,450, about 62% less; arguably a different class. |
A Revel W783 B Revel W553L
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 W783 has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Revel W553L is the easier speaker to get right. Think about the whole system, not just the speakers: the roughly $905 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.