EddNog
Active Member
Let me start off with the included dongle. I echo the thoughts of others when listening to the HDB 630s using the BTD 700--even at the highest performance protocol (as confirmed in the Sennheiser SmartControl Plus app), the cans do not sound as good as when connected via USB-C. The sound literally seems grainy when playing over the dongle. I will spend some more time later trying to figure out what may be the cause, but even when it's on AptX Adaptive and the phone/dongle are in my hands with the cans on my head, the sound is grainy. So with that all said, the rest of my impressions are with the cans playing over USB-C.
Moving over to the HDB 630s themselves...
First off, the Crossfeed function (set to Low) is excellent. It does not have any adverse effects on tonality or detail extraction, but imaging is significantly more natural and nuanced with this on. Just on this alone, I would choose these cans over my HD 6XX or my AirPods Max, as well as preferring these cans over any of my IEMs (when the weather is nice and cool). Overall, in my opinion, the Crossfeed function does more for imaging than having open backs like the HD 6XX.
For overall tonality, I am extremely pleased with the default tuning, and feel no need whatsoever to apply any (P)EQ adjustments. The HDB 630, for me, perfectly make up for the soft bass of HD 6XX without any detriment to the rest of the frequency range. Tuning is just right. Compared to AirPods Max, I would argue that bass on the HDB 630 (over USB-C) is more natural and balanced than AirPods Max, which has more punch, but at times the bass can seem a bit exaggerated--not so for me with HDB 630, bass tuning is just right. On the mids and highs, it is no contest, I'll take HDB 630 or HD 6XX every single time over AirPods Max. It's simply another level of transparency and natural sound. Between HD 6XX and HDB 630, I'm happy with either, as the difference is highly nuanced. There is only a slightly greater hint of air with HD 6XX, but the difference is far from night and day.
Now let's talk about the ANC, transparency, and wind filtering. First of all with full ANC forced, I'd rate the ANC effectiveness a 7/10. It's fine. It's not the best. The best I've seen is AirPods Pro 3, followed by AirPods Max, followed by AirPods Pro 2. Actually, the best ANC I've ever experienced was wearing listening to AirPods Pro 3 with ANC on, simultaneously with a pair of AirPods Max worn over them with ANC on (yes, seriously)--but I digress, we're here to talk about HDB 630. Transparency mode forced full on without wind filtering enabled works okay, I'd rate it maybe a 7/10 if the wind noises don't get to you; however, they get to me. Now if you're indoors and turn on wind filtering, it improves Transparency mode performance probably to 8/10 (with AirPods of any kind still being the king). However...once you go outdoors to a noisy environment, like, say, Center City Philadelphia, things fall off a cliff. The wind filtering seems to detect all sorts of non-wind-noises as wind, and ends up basically turning Transparency mode into ANC mode (it is trying to block sounds that are not wind, and end up just blocking everything). Turning off wind filtering outdoors is also basically unusable--due to actual wind noise. So ironically, Transparency mode outdoors is really not great as a whole, maybe 5/10. Indoors it works fine, 7/10. I think of all the HDB 630's isolation features, the ANC with wind filtering on is probably the most effective at doing what it's supposed to do. Finally I don't understand Adaptive mode for ANC, it didn't appear to perform any differently than simply having ANC maxed out. Unlike on Apple AirPods, with Adaptive ANC mode turned on, when I start talking, it doesn't adapt to me and change to Transparency so that I can have a conversation with other people. The Apple stuff works stunningly well for this.
Finally, the Sennheiser SmartControl Plus companion app for these cans is pretty good. It is a bit finicky when trying to work with the included BTD 700 dongle (need to connect to the phone's BT radio for the app to work, but need to also connect to and select the BTD 700 from list of output devices in order to actually get AptX Adaptive etc.). It also needs to be connected to the phone's BT radio when connected and playing via USB-C. With all that sorted out, functionality-wise, the app is great. UI is intuitive, it's smooth, and everything just works on my iPhone. I did try the app on my Android-based DAP (FiiO JM21) and I could not get it to work properly with it, so caveat emptor (I am able to add the cans to the app, but tapping on the cans in the app on Android didn't respond at all so I couldn't actually bring up the controls on my Android DAP).
-Ed
Moving over to the HDB 630s themselves...
First off, the Crossfeed function (set to Low) is excellent. It does not have any adverse effects on tonality or detail extraction, but imaging is significantly more natural and nuanced with this on. Just on this alone, I would choose these cans over my HD 6XX or my AirPods Max, as well as preferring these cans over any of my IEMs (when the weather is nice and cool). Overall, in my opinion, the Crossfeed function does more for imaging than having open backs like the HD 6XX.
For overall tonality, I am extremely pleased with the default tuning, and feel no need whatsoever to apply any (P)EQ adjustments. The HDB 630, for me, perfectly make up for the soft bass of HD 6XX without any detriment to the rest of the frequency range. Tuning is just right. Compared to AirPods Max, I would argue that bass on the HDB 630 (over USB-C) is more natural and balanced than AirPods Max, which has more punch, but at times the bass can seem a bit exaggerated--not so for me with HDB 630, bass tuning is just right. On the mids and highs, it is no contest, I'll take HDB 630 or HD 6XX every single time over AirPods Max. It's simply another level of transparency and natural sound. Between HD 6XX and HDB 630, I'm happy with either, as the difference is highly nuanced. There is only a slightly greater hint of air with HD 6XX, but the difference is far from night and day.
Now let's talk about the ANC, transparency, and wind filtering. First of all with full ANC forced, I'd rate the ANC effectiveness a 7/10. It's fine. It's not the best. The best I've seen is AirPods Pro 3, followed by AirPods Max, followed by AirPods Pro 2. Actually, the best ANC I've ever experienced was wearing listening to AirPods Pro 3 with ANC on, simultaneously with a pair of AirPods Max worn over them with ANC on (yes, seriously)--but I digress, we're here to talk about HDB 630. Transparency mode forced full on without wind filtering enabled works okay, I'd rate it maybe a 7/10 if the wind noises don't get to you; however, they get to me. Now if you're indoors and turn on wind filtering, it improves Transparency mode performance probably to 8/10 (with AirPods of any kind still being the king). However...once you go outdoors to a noisy environment, like, say, Center City Philadelphia, things fall off a cliff. The wind filtering seems to detect all sorts of non-wind-noises as wind, and ends up basically turning Transparency mode into ANC mode (it is trying to block sounds that are not wind, and end up just blocking everything). Turning off wind filtering outdoors is also basically unusable--due to actual wind noise. So ironically, Transparency mode outdoors is really not great as a whole, maybe 5/10. Indoors it works fine, 7/10. I think of all the HDB 630's isolation features, the ANC with wind filtering on is probably the most effective at doing what it's supposed to do. Finally I don't understand Adaptive mode for ANC, it didn't appear to perform any differently than simply having ANC maxed out. Unlike on Apple AirPods, with Adaptive ANC mode turned on, when I start talking, it doesn't adapt to me and change to Transparency so that I can have a conversation with other people. The Apple stuff works stunningly well for this.
Finally, the Sennheiser SmartControl Plus companion app for these cans is pretty good. It is a bit finicky when trying to work with the included BTD 700 dongle (need to connect to the phone's BT radio for the app to work, but need to also connect to and select the BTD 700 from list of output devices in order to actually get AptX Adaptive etc.). It also needs to be connected to the phone's BT radio when connected and playing via USB-C. With all that sorted out, functionality-wise, the app is great. UI is intuitive, it's smooth, and everything just works on my iPhone. I did try the app on my Android-based DAP (FiiO JM21) and I could not get it to work properly with it, so caveat emptor (I am able to add the cans to the app, but tapping on the cans in the app on Android didn't respond at all so I couldn't actually bring up the controls on my Android DAP).
-Ed