A generation apart: Sony Signature Series SA-Z1 is the newer design, against a 2016 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 | Dynaudio Focus 20 XD digs deeper - 39Hz against 51Hz. |
| Built-in power | B | Dynaudio Focus 20 XD has the bigger amplifier (300W vs 212W RMS). |
| Connections | B | Dynaudio Focus 20 XD adds Bluetooth. |
| Size | depends | Sony Signature Series SA-Z1 is easier to place; Dynaudio Focus 20 XD is bigger, which usually goes with fuller bass. Your room decides. |
| Price | B | Dynaudio Focus 20 XD is cheaper - $6,000 against $8,000, about 25% less. |
A Sony Signature Series SA-Z1 B Dynaudio Focus 20 XD
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?
Dynaudio Focus 20 XD is the easier recommendation: it leads on most of the measured areas and costs less. Take Sony Signature Series SA-Z1 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 51Hz anyway, so judge these on the other rows instead. In a large or open-plan room, Dynaudio Focus 20 XD has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Sony Signature Series SA-Z1 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.