Sennheiser HDB 630 Headphone Brings aptX Adaptive Bluetooth To iPhone

Sennheiser recently launched the HDB 630 ($499.95), a new wireless ANC headphone packed with “a suite of fidelity-first features, advanced tuning, and modern mobility comforts,” according to the German brand. The HDB 630 is described as a do-it-all headphone designed for the listener who wants function and fidelity while on the move, reportedly delivering “uncompromised sound, no matter the setting.” Fans of the brand will recognize that the physical design of the HDB 630 is based on the best-selling Momentum 4 (originally launched in 2022, now discounted to $250), but Sennheiser says that the new model “supercharges” the versatile design of the Momentum 4 with a new high-resolution sound engine, new tuning, and new acoustic treatments inside the HDB 630’s slightly larger ear cups.

The chassis of the HDB 630 is indeed inherited from the Momentum 4, so the build quality and overall ergonomics should be similar. While its mostly plastic components won’t make the HDB 630 feel as premium as something like the $800 Bowers & Wilkins Px8 S2 or the $1,300 Focal Bathys MG, Sennheiser cans have a reputation of standing up to the test of time despite their lightweight build. With most of the headphone’s structure based on a previous design, Sennheiser was able to focus its R&D budget on sound quality, developing a customized acoustic system “built for focused listening — with or without a cable,” according to the company. The HDB 630 uses a 42 mm dynamic transducer, made at the brand’s state-of-the-art Tullamore production facility in Ireland. The driver is assisted by a series of acoustic treatments designed to deliver “balanced audio with impressive clarity,” according to Sennheiser. The brand stresses that the sound of the HDB 630 is about “purity, not hype.” In subjective terms, that translates to smooth mids, intimate vocals, and speedy dynamics that contribute to “an effortlessly agile listen,” according to Sennheiser. We’re told that the headphone’s tuning has been shaped to be non-fatiguing and relaxed, but not lacking in detail. It makes the headphone “the ideal foundation for serious listening when you still want modern comforts like noise cancelling and Bluetooth connectivity,” according to a statement from Sennheiser. Compared to the tonal balance of the popular Momentum 4, the sound signature of the new model is more refined, according to the company. The slightly larger back volume of the ear cups makes room for a new magnet damper that reportedly tames upper-midrange and treble energy. Meanwhile, an all-new protective acoustic mesh was selected for the front volume, “with a light impedance that disappears from the audio path. The resulting detail is impressively smooth, all while retaining a response curve that is pleasant to absorb for hours on end,” according to Sennheiser. Just as important to many users will be a new toolkit of audio goodies like parametric EQ and Crossfeed, offering greater control over the sound and user experience.

We set out to deliver a compelling option for audiophiles who want to keep the same level of quality they’re used to with their wired headphones while enabling them to enjoy it everywhere, and out of the box, the HDB 630 brings a truly unique combination of fidelity and customization.

— Wee Hong Kuan, Senior Product Manager

The aim of this tuning was to let audiophiles on the move enjoy balanced sound with extended yet controlled bass. Whether plugging in or checking in, you always get a front-row seat to the emotional content in a recording, down to the last detail.

— Tobias Ritter, Acoustic Engineer for HDB 630

Sennheiser HDB 630: High Resolution On-The-Go

The HDB 630’s acoustic platform is maximized by a high-resolution digital audio engine that can be used wired or wirelessly in a variety of setups. For the best possible fidelity, users can listen via the included USB Type-C cable, connecting directly to their local or streaming library via a smartphone, tablet, or computer. The headphones offer native support for music up to 24-bit/96kHz resolution. When going wireless, the headphones have Bluetooth 5.2 with aptX Adaptive codec support, providing “robust streaming capabilities that prioritize sound quality and signal stability,” according to Sennheiser. One unique (and potentially game-changing) feature is the included USB Type-C transmitter dongle, which can attach to just about any smartphone, tablet, or computer, instantly upgrading these source devices to high-resolution aptX Adaptive capability. As Sennheiser points out, there’s little use in buying a headphone that uses aptX Adaptive if your smartphone doesn’t support it. According to Sennheiser, only an estimated 16% of smartphone hardware supports native wireless high-res sound. One big reason for this is that the iPhone, which remains the single most popular smartphone worldwide, only supports the AAC Bluetooth codec, with a relatively low bit-rate of about 256kbps (theoretically variable from 128kbps to 320kbps, with 256kbps being the average). Neither the Google Pixel nor the Samsung Galaxy family currently supports Qualcomm’s aptX codec (though Android phones do support Sony’s competing LDAC codec). But by attaching the included dongle to a phone’s USB Type-C port, you can take advantage of the HDB 630’s aptX Adaptive support and enjoy higher-quality wireless audio with just about any phone, even an iPhone. The included BTD 700 dongle, which Sennheiser also sells separately for $60, works on over 80% of smartphones, according to Sennheiser.

Sennheiser HDB 630: What About aptX Lossless?

AptX Adaptive uses Dynamic bitrate and latency adaptation, typically streaming at bitrates between  279kbps and 420kbps. Qualcomm claims that its unique compression tech yields higher sound quality than other codecs at the same bitrates, and it supports audio streams up to 24-bit/96kHz. The uppermost level of aptX Adaptive is aptX Lossless, which was first announced in 2021. Qualcomm describes aptX Lossless as a new capability of the aptX Adaptive codec, aimed to deliver CD-quality, 16-bit/44.1kHz lossless audio over Bluetooth. It’s worth pointing out that no other Bluetooth codec can transmit lossless audio. AptX Lossless uses Qualcomm Bluetooth High Speed Link technology to scale up to bitrates of about 1.2 Mbps in favorable RF environments. (See our article Is Qualcomm’s New ‘aptX Lossless’ Technology The Holy Grail of Bluetooth?). But aptX Lossless only works when supported by both the source component and the headphones. The BTD 700 dongle does support aptX Lossless, but as of now, the new HDB 630 headphones do not. Sennheiser has not ruled out adding support for this desirable feature via a future firmware update, but its absence at launch feels like a missed opportunity.

At the moment we do not have aptX Lossless baked in…, as its bit-perfect sound is exceptional but caps out at 16-bit. AptX Adaptive's hi-res mode is the best mixture of meaningful resolution x word length and scaling quality so you can have continuity of signal. No setup will have 100% perfect transmission but with all of the hi-res content now available, we can offer a reliably great path to high-res content and a number of connection options that are still convenient. 

— Eric Palonen, PR Manager, Sonova Consumer Hearing (Sennheiser’s parent company)

Sennheiser HDB 630: New Tools

The HDB 630 includes new sound-shaping tools to let listeners go beyond the genre presets offered by many wireless headphones. The Smart Control Plus app provides access to a 5-band equalizer and a new Crossfeed feature inspired by Sennheiser’s flagship $60K electrostatic headphones, the HE 1. Sennheiser says that the crossfeed is not a mere gimmick, and that it can give the HDB 630 a speaker-like presentation, “perfect for hard-panned mixes that can be fatiguing for headphone listening.” (If you have ever listened to the early stereo mixes of the first several Beatles albums, you know exactly what Sennheiser is talking about.) But the bigger story seems to be Sennheiser’s new Parametric Equalizer, which lets listeners boost and cut frequencies beyond those offered in a traditional graphic EQ interface. It comes complete with user-adjustable bandwidth (Q) controls, filter types, an A/B toggle, and more. Interestingly, you’ll be able to share your favorite EQ settings with other HDB 630 users through the app. A future update will enable sharing through QR code generation — something I have never seen before. Smart Control Plus users can also customize intelligent features like noise cancellation, on-head detection, and codec preference.

 Sennheiser HDB 630: Comfort And Use

 

Although the overall build quality of the HDB 630 is similar to that of the Momentum 4, Sennheiser says that the top-of-headband material has been upgraded from cloth to Japanese Protein Leatherette from IDEATEX. This material is renowned for “touch and durability, maximizing the enjoyment of every listening session,” according to Sennheiser. The protective travel case that ships with the HDB 630 is reportedly much more rigid than the Momentum 4 case, and comes loaded with a USB Type-C charging cable, a 3.5 mm analog audio cable, an airline adapter, and the aforementioned USB Type-C Bluetooth transmitter. The headphone offers an impressive 60 hours of battery life per charge. Its quick-charge capability provides 7 hours of listening in just 10 minutes.

CanJam Dallas

Sennheiser showed off the new HDB 630 for the first time at CanJam Dallas, one of many such meetups arranged by the online headphone enthusiast community Head-Fi. CanJam Dallas which took place Saturday, November 8 and Sunday, November 9 at the Dallas/Addison Marriott Quorum by the Galleria. Attendees will be able to compare the HDB 630 against the Momentum 4 and other HD series headphones. Sennheiser will also bring its flagship $60K HE 1 headphone system for your listening pleasure

More information: CanJam Dallas 2025

 

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