A generation apart: Q Acoustics M20 HD is the newer design, against a 2013 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.
| Area | Better | Why |
|---|
| Bass | B | Q Acoustics M20 HD digs deeper - 55Hz against 74Hz. |
| Built-in power | B | Q Acoustics M20 HD has the bigger amplifier (128W vs 50W RMS). |
| Connections | B | Q Acoustics M20 HD adds Bluetooth, streaming and digital inputs. |
| Size | depends | Genelec G One is easier to place; Q Acoustics M20 HD is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | B | Q Acoustics M20 HD: a sub output. |
| Price | B | Q Acoustics M20 HD is cheaper - $599 against $700, about 14% less. |
A Genelec G One B Q Acoustics M20 HD
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?
Q Acoustics M20 HD is the easier recommendation: it leads on most of the measured areas and costs less. Take Genelec G One if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 74Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Q Acoustics M20 HD has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Genelec G One 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.