Bose QuietComfort Ultra Headphones vs Sennheiser HDB 630

Bose QuietComfort Ultra Headphones

Rich, warm sound signature that most listeners will enjoy, though audiophiles may want more neutrality.

• The sound is warm, rich, and engaging — Bose has clearly invested in tuning these for mainstream appeal.
• Immersive Audio is genuinely impressive for movies and spatial music mixes, but it's a battery hog.

Sennheiser HDB 630

The HDB 630's headline strength. Reviewers describe a warm-neutral, natural HD 600-series tuning with a standout midrange, an open and spacious soundstage for a closed-back, and enough neutrality to make it the most EQ-friendly wireless headphone on the market. The consensus is that it is the best-sounding wireless headphone at $500.

• Crinacle calls it the best-sounding premium wireless headphone available today — nothing is over- or under-emphasised, everything just sounds natural and 'normal'.
• The Headphone Show says that even without touching the app or EQ, the HDB 630 is the best-sounding wireless noise-cancelling headphone in its price range.
• GadgetryTech calls it the best-sounding active Bluetooth headphone they've ever heard out of the box — tuned better than most or all closed-back Bluetooth headphones.
• The tuning carries classic HD 600-series traits — a warm-neutral balance and a great midrange — though one reviewer flags a slightly slow bass.
• The midrange is the standout of the tuning, and Picky Audio named the HDB 630 best-sounding headphone of 2025 for its rare balanced tuning.
• There is a slight forward character in the 1-2kHz midrange and a low-treble forwardness around 3-4kHz; the bass stands out in good ways without being a bass-boost machine.
• Joshua Valour says soundstage width, placement and fidelity keep up with the best closed-backs, though they still can't match the best open-backs for soundstage.
• A Reddit owner describes it as the most crystal-clear, almost open-back-sounding closed-back headphone they have ever heard, and was surprised by the soundstage.
• Soundnews estimates soundstage and depth improved by roughly 20-25% over the Momentum 4.
• Dissent: an older review of a different Sennheiser model warns the brand's bass-heavy tunings aren't ideal for classical or vocal music — but HDB 630 reviewers consistently describe a far more neutral, balanced signature.

Bose QuietComfort Ultra Headphones

Premium build and excellent comfort, though slightly heavier than the previous generation.

• These are incredibly comfortable for multi-hour listening sessions — the protein leather earpads are plush.
• They're noticeably heavier than the QC45 — I felt it after 3+ hours of continuous wear.

Sennheiser HDB 630

At ~311g the HDB 630 has plush, beefed-up padding and folds for travel, and most reviewers find it comfortable for long sessions with a lighter clamp than the Momentum 4. The recurring criticism is the mostly-plastic build, which several reviewers say feels under-premium for a $500 headphone, and ear pads that are not the most spacious for larger ears.

• At 311g (up from the Momentum 4's 295g) the extra mass is barely noticeable and comes from significantly beefed-up padding.
• The Headphone Show finds the HDB 630 more comfortable than the Momentum 4 because the clamp force is lighter and the headband distributes pressure more evenly.
• Picky Audio notes the ear pads still aren't the most spacious — ears touch the inside — but says it's easy to get used to and wear either headphone for long periods.
• One comparison reviewer found the HDB 630 needs a short break after about 2 hours of wear, where the lighter 263g Bose QC Ultra can be worn for hours without one.
• Joshua Valour likes the headphones but wishes the build quality felt a little more premium for $500.
• BrandsWalk wishes the design were more premium at the price — even just swapping plastic for metal on the headband — but rates it the best Sennheiser of recent years.
• Super Review points out the cups look like aluminium but are actually plastic, and the reviewer wishes they were finished in plain black.
• Moon Audio praises exceptional all-day comfort, premium Japanese leatherette pads, a fingerprint-resistant matte finish and a travel-friendly folding design.
• RTINGS warns the HDB 630 may not be the best choice for people who wear thicker-framed glasses, as the seal can be affected.
• GadgetryTech notes generous ear clearance — about 5mm — which makes the difference between taking the headphones off mid-flight or leaving them on for hours; aftermarket pads (e.g. Wicked Cushion freeze pads) expand the cavity further at the cost of ~50g of added weight.