These sit in different price classes - Buchardt A700 costs roughly 13.2x what Fluance Ai81 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | B | Buchardt A700 digs deeper - 17Hz against 30Hz. |
| Built-in power | B | Buchardt A700 has the bigger amplifier (600W vs 150W RMS). |
| Connections | A | Fluance Ai81 adds Bluetooth and digital inputs; Buchardt A700 adds Wi-Fi. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Cabinet | depends | Ported vs Sealed. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it. |
| Expandability | A | Fluance Ai81: a sub output. |
| Price | A | Fluance Ai81 is cheaper - $499 against $6,600, about 92% less; arguably a different class. |
A Fluance Ai81 B Buchardt A700
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. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 30Hz anyway, which makes the cheaper Fluance Ai81 much easier to justify. Think about the whole system, not just the speakers: the roughly $6,101 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.