A generation apart: Klipsch The Fives 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 | evenly matched | Much the same reach (50Hz vs 50Hz). |
| Built-in power | A | Klipsch The Fives has the bigger amplifier (160W vs 100W RMS). |
| Connections | A | Klipsch The Fives adds HDMI and phono. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Klipsch The Fives: a sub output; Audioengine HD6: a sub output. |
| Price | B | Audioengine HD6 is cheaper - $699 against $969, about 28% less. |
A Klipsch The Fives B Audioengine HD6
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: Klipsch The Fives measures better, Audioengine HD6 costs about about 39% 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. Think about the whole system, not just the speakers: the roughly $270 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.