Different kinds of product: one is active with its amplifier built in, the other passive and needs one. Judge them on how you want to own the system, not just the specs.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (35Hz vs 35Hz). |
| What you buy | depends | Cambridge Audio L R X is a complete system - just add a source. Monitor Audio Silver 100 7G also needs an amplifier: more money and another box, but you choose it. |
| Connections | depends | Cambridge Audio L R X has HDMI built in. With Monitor Audio Silver 100 7G that all comes from the amplifier you pair it with. |
| Upgrade path | depends | Monitor Audio Silver 100 7G can be re-amped later and outlive several amplifiers; Cambridge Audio L R X ages as one unit. |
| Size | depends | Cambridge Audio L R X is easier to place; Monitor Audio Silver 100 7G is bigger, which usually goes with fuller bass. Your room decides. |
| Cabinet | depends | Passive Radiator vs Ported. |
| Expandability | B | Monitor Audio Silver 100 7G: bi-amping. |
| Price | B | Monitor Audio Silver 100 7G is cheaper - $1,400 against $2,299, about 39% less; arguably a different class. Speakers only - an amplifier narrows that gap. |
A Cambridge Audio L R X B Monitor Audio Silver 100 7G
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?
Cambridge Audio L R X suits you if you want one box, ready to play, with nothing else to buy. Monitor Audio Silver 100 7G suits you if you already have an amplifier, want to choose the electronics, or expect to upgrade in stages. Neither is the better speaker in the abstract. In a large or open-plan room, Monitor Audio Silver 100 7G has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Cambridge Audio L R X is the easier speaker to get right. Think about the whole system, not just the speakers: the roughly $899 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.