I’ve just finished testing the Sennheiser HDB 630, and when I tell you I’ve had a marvelous time, I mean it. They’re a truly stunning pair of the best headphones, with epic sound quality, a comfortable fit and battery life that conquers everything else in the same price range.
But their ace in the hole, their piece de resistance, the trick up their sleeve is what really makes me love them. In their protective case there’s a little magic USB-C dongle, and it’s going to change the game for audiophiles on the go who wield an iPhone or an older Android handset.
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Not all devices are created equal
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Your phone might not support the best wireless music standards. I’m sorry to let you know like this, I hope you’re sitting down. Let me know if you need a second to go and make a cup of coffee and grab yourself a cookie. It’s ok. We’ve all been there.
See, there are ways to listen to higher-quality audio over a wireless connection. They’re not as good as cabled listening (of any kind), but codecs like LDAC and aptX can transfer higher resolution “lossless” tracks wirelessly. They’re not perfect — they can never be truly “lossless” — but they’re better than traditional wireless transmission over Bluetooth.
Alas, not all devices support such witchcraft. iPhones only have ALAC, which is only going to work with AirPods, and some Android handsets don’t have any high-quality codec at all. So what is there to do when your phone doesn’t want to play nicer-sounding tracks on headphones that are begging for it?
You need a dongle.
Enter the BT700
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“Ugh,” I hear you cry. “Another dongle? I’ve got loads of those for my MacBook that only has USB-C ports.” Yes, well, here’s another one. You want the best sound? This is how you get it. It’s not that bad — it’s really small. And there’s even a place you can pop it in the case so you don’t lose it. On account of it being really small, and thus eminently losable.
Despite being tiny, it’s a super cool little piece of kit. Plug it into the USB-C port of your device, and it introduces a new connection method to your device — one that supports high-quality codecs for better-sounding audio. You can plug it into your iPhone, your laptop, your tablet… the possibilities are endless.
It’s easy to use as well. Plug it in, press and hold the little button, and put the headphones into pairing mode. Give it a second, and everything works together as one cohesive whole. No messing about. It’s great!
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Sound gains
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So you’re all connected up, and you’re ready to listen to your favorite tunes in high quality with the fancy dongle attached. Remember, it’ll only sound as good as the stuff you’re putting into it, so don’t expect earth-shattering improvements if you’re using low-quality Spotify streams in an effort to save data. Crank up the lossless mode, or, even better, invest in Qobuz — it’s our pick for the best music streaming service for audiophiles.
I plugged the dongle into my iPhone 17 Pro Max, a $1,299 device that doesn’t support high-quality audio for anything other than AirPods. (Don’t get me started. I don’t have the time or the moral fortitude.) Immediately, I found more detail. The headphones were able to reveal more dimensions to bass notes, find minute sections that are otherwise destroyed in the compression process for wireless transmission. I could hear more of the instruments as they moved around in the recording studio. The drummer slamming his sticks on the rim of his snare, guitarists running picks down fretboards.
The bass is more dynamic. The mids are fuller, the highs clearer. They’re all subtle differences, but add them all together and you’re in for a sonic treat. Instrument separation, soundstage increases — and it’s all down to a little Bluetooth dongle that comes with your headphones.
Sennheiser, you spoil us.
Even more ways to listen
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If you want even better sound, you can plug the Sennheiser HDB 630 into your listening device with a wire. They sound even better when you do as well — the headphones at the core of the experience are a truly spectacular pair of cans with a delicate, well-considered sound profile. But I can do that with the Sony WH-1000XM6 and the Bowers & Wilkins PX7 S3 — I can’t use those with high-quality codecs on my iPhone without buying a separate device.
It’s not perfect, of course. It occupies the charging port of your phone and drains some of the battery in pursuit of sound quality. The connection feels slightly delicate in your pocket as well — but I think it’s all worth it for better audio on the go. Of course, it’s all moot if your device already supports LDAC and aptX. You lucky creature.
The fact that Sennheiser has packed the dongle into the box and not charged extra for it should make other manufacturers prick up their ears and listen. There is a desire for higher quality listening wirelessly — Spotify Lossless and its sudden popularity is great evidence — and users’ devices need to be ready for it.
The Sennheiser HDB 630 are ready for it. Are you?
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