No single best speaker here - they are built to different priorities, and the right one depends on your room, your sources and what you listen to.
| Area | Better | Why |
|---|
| Bass | A | Edifier MR4.5 digs deeper - 50Hz against 55Hz. A subwoofer would even that out. |
| Built-in power | B | Onkyo Creator Series GX-30ARC has the bigger amplifier (100W vs 80W RMS). |
| Connections | B | Onkyo Creator Series GX-30ARC adds HDMI, phono and digital inputs. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | B | Onkyo Creator Series GX-30ARC: a sub output. |
| Price | A | Edifier MR4.5 is cheaper - $250 against $349, about 28% less. |
A Edifier MR4.5 B Onkyo Creator Series GX-30ARC
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?
The usual trade-off: Onkyo Creator Series GX-30ARC measures better, Edifier MR4.5 costs about about 40% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 55Hz anyway, so judge these on the other rows instead. Think about the whole system, not just the speakers: the roughly $99 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.