The Qian69 are supposedly an upgrade for Qian39, and despite the similarity between the sound signatures, QianYun definitely nailed it with Qian69 when it comes to sound quality. Unlike Qian39, the Qian69 are extremely well-balanced: the lower frequencies were tuned-down a bit, while the upper-mids and the upper-highs were enhanced to offer a more fun and true-to-life musical experience.
Despite the not-so-promising cable QianYun used for these earbuds, I'm more than sure that I can recommend them for anyone who prefers earbuds over in-ears. These are a real catch, especially for the price.
Some people might disagree, but I find the Qian69 just a bit less comfortable than the previous Qian39 model, perhaps due to their larger size.
Lows / Bass
Just like Qian39, the bass is unashamedly prominent and extended down to the lowest sub-bass. Mid-bass is well-balanced, which means the sound is warm but doesn't get muddy most of the time, when the recording is of good quality. However, on a lower-quality recording with basslines, the bass can get muddy sometimes, which is a common theme with earbuds in general.
Mids / Vocals
Unfront mids and vocals, crisp instrument reproduction and separation. Despite being so prominent in the sound signature, they are not edgy and there are no sudden peaks, which basically means that you're up for a very comfortable listening experience even for the most prolonged sessions.
Highs / Treble
The treble is bright, sparlkly and highly detailed. Precisely in balance with lower frequencies and never sounds too loud or too convoluted with its amount of detail. Granted, I think that Headroom MS16 exposes even more microdetail, but the sound balance as a whole seem far more well-thought-out on Qian69 than other earbuds I've tested so far.