Superlux HD-681chat_bubble_outlineFrom real comments

Exceptional sound quality for the price, with detail and soundstage that rival pricier headphones. Commenters repeatedly call the HD-681 an 'amazing investment' and say it beats headphones two to four times its price, citing clarity, punchy bass, and a wide, spacious soundstage. Several directly compare it to AKG K702 and DT770-class headphones and prefer it in certain respects. Even skeptical buyers who found it disappointing at first often warmed to it after adjustment, and long-term owners across multiple years continue defending it as best-in-class budget value.

Treble is bright or harsh out of the box but improves dramatically with burn-in. Many first impressions mention piercing or fatiguing highs, especially through weak sources like onboard sound cards or phones. However, a large number of reviewers say 50 to 200 hours of burn-in tames this significantly, leaving a much more even, listenable sound. Some also roll off treble manually with EQ or foam inserts. A minority still find the highs unbearable even after time, and some think they simply weren't used to a neodymium driver's brighter signature.

Build quality and comfort are inconsistent, with pad swaps and cable issues commonly reported. While some owners report years of rough daily use without failure, others experienced sudden driver death, torn cables, or the male-to-female jack design failing within weeks or months. Many users found the stock leatherette pads sweaty or uncomfortable and swapped them for velour or aftermarket pads (often AKG-compatible), which also helped reduce treble harshness and improved overall comfort and fit.