Before you start…
The HDB 630 features our 42 mm dynamic transducer, built in Ireland. To achieve the target acoustic performance, in addition to a custom Digital Signal Processing tuning, we also updated the acoustic system with enhanced damping, a new acoustic mesh on the magnet, and a deeper back volume to compliment the mesh.
The enhanced damping (dust cover) provides relative acoustic transparency and compliments higher frequencies, all of which assist the final frequency response to achieve its Hi-Res Audio certification.
The acoustic mesh on the magnet hole helps to shape the upper mid-range and control the target treble, which together enable a more efficient DSP tuning.
The new, deeper back volume was designed to complement the acoustic mesh, helping to maintain a high level of consistency across the product range.
The HDB 630 supports aptX Adaptive with up to 24-bit/96 kHz sampling rate, allowing you to enjoy high-quality content on the go. The Adaptive ANC removes background distractions to help users hear more of their music. Its lightweight build, low clamping force, generous earcups, and premium Japanese leatherette headband ensure hours of fatigue-free listening.
The HDB 630 supports SBC, AAC, aptX, aptX-HD, and aptX Adaptive.
It comes with a BTD 700 to upgrade compatible USB-C devices (such as your smartphone or tablet) into a hi-res aptX Adaptive transmitter.
The HDB 630 headphones are designed to deliver a best-in-class audiophile wireless listening experience. If customers wish to use the HDB 630 for casual gaming, they should consider whether the microphone response and connection latency are sufficient for their requirements.
1) AptX Adaptive latency (80 ms) from Qualcomm or
2) USB audio – max. latency 40 ms, USB mic – max. latency 40 ms
3) Aux mode (no microphone) – 30 ms
The HDB 630’s tuning results from an updated acoustic design – including damping materials, a deeper back volume not used in the MOMENTUM 4, and advanced Digital Signal Processing – to achieve a more neutral acoustic performance.
While users may use a third-party parametric equalizer to adjust the frequency response, this often reduces headroom and maximum perceived volume and may not achieve the desired result due to differences in acoustic system design.
The HDB 630 will start auto-pairing out of the box. Users can activate pairing by pressing and holding the multi-function button for 5 seconds with the headphones switched off. The LED sequence will light up to indicate that the pairing process has started.
The BTD 700 can be connected to any compatible USB-C device, and must be paired with the headphones before use. To maximize battery runtime, hi-res (24-bit/96 kHz) is not turned on by default, so the user must activate hi-res in the Smart Control Plus App.
The user may need to select BTD 700 as the output on their device, under the output settings on e.g. Googlecast/Airplay.
The USB audio supports Plug & Play on compatible devices, with no driver required.
To enjoy 24-bit/96 kHz, Windows and Mac devices may require the user to increase the sampling rate manually in the device’s sound settings.
Up to 24-bit/96 kHz.
The HDB 630 can run for up to 60 hours at standard resolution.
When using aptX Adaptive 24-bit/96 kHz with the BTD 700, they can run for up to 45 hours.
The headphones are charged via the supplied USB-C to USB-C cable.
The HDB 630 are not waterproof or sports headphones.
All Sennheiser products are intensively tested for product quality and reliability. Our quality tests include several mechanical, electrical, thermal, chemical (e.g., dust and splash resistance), drop, UV color stability, scratch and rub, battery safety and ESD tests, as well as tests for RF/Bluetooth® stability and interference, etc.
These tests allow us to validate the product’s reliability and robustness for a long service life, even in tough conditions. If your product is damaged or malfunctions, you are covered by our global warranty program:
You can pair the HDB 630 with up to two devices simultaneously, and it can store up to six paired devices in its memory.
Yes, and users can enjoy the new parametric equalizer and crossfeed feature with the Smart Control Plus App. The HDB 630 does not work with the Smart Control App, original version.
The headphones’ batteries cannot be exchanged. The HDB 630 uses high-quality, embedded, rechargeable Li-Ion batteries that are intensively tested and certified to the highest international quality standards. They are sealed inside the housing for high robustness. The headphones are built to last a long time, and we offer replacement parts and a global warranty program.
Further information e.g., a downloadable user manual, can be found on Sennheiser’s HDB 630 product page in the section “Downloads”. Several how-to videos are also available in the FAQs on the product page and on YouTube.
Our BTD 700 is a hi-res transmitter that works with iOS devices with a USB-C connector. For iOS devices with a lightning port, users will need a compatible USB-C to Lightning adapter that supports Audio. We recommend that users source MFi-certified adapters.
As we use advanced Digital Signal Processing in part to craft the desired acoustic performance, the HDB 630 can only be used while switched on, to ensure the user hears a consistent sound signature no matter which input they use.
During use…
We recommend all users check for and install the latest updates on their HDB 630 to enjoy the best experience.
For the best wireless quality, use the USB-C Bluetooth® transmitter BTD 700 to enjoy hi-res audio content with any compatible USB-C device.
1) Consider turning on Hi-Res mode for hi-res Bluetooth® sound quality. This may reduce wireless runtime from up to 60 hours to up to 45 hours.
2) When using the BTD 700, check whether the LED turns pink, which indicates active transmission. Otherwise, check that the BTD 700 is selected as the output device on the Cast options.
3) Users can check this in Smart Control Plus App > Settings > Signal Path on Codec and Sampling rate.
4) Sound quality and volume leveling may be app- and device-dependent. Please check the respective audio settings to ensure the right ones are selected.
You can view the transmission codec and sampling rate via the Smart Control Plus App’s Signal path.
Please note that resolution is dependent on the music source sampling rate, and that the Bluetooth® codec does not support up-sampling.
aptX Adaptive is a scalable codec that adjusts the bitrate based on environmental conditions to maintain a stable connection.
In addition, if aptX Adaptive is activated for every playback, it will gradually scale up from a nominal to a higher bitrate over 20 seconds to ensure an uninterrupted experience.
High-resolution signals are required to achieve a frequency range of 6 Hz to 40 kHz. This can be achieved over 24-bit/96 kHz on aptX Adaptive, USB audio and analog inputs. For other signals, the speaker may output a frequency response range of 6 Hz to 22 kHz.
The headphones have an auto-off function, and the user can select the duration (15/30/60 mins and Never) via their Smart Control Plus App. The headphones will also turn off automatically when placed correctly in their carrying case.
Keep all liquids away from the product. Do not use any solvents or cleaning agents. We recommend cleaning the headband silicone and earpads frequently, especially after intense use or before/after storing for a long period of time. Wipe off any residual grease from skin contact to help extend the material lifespan. Only use a soft, dry cloth to clean the product.
To clean the charging socket: Blow vigorously over the charging socket. If necessary, carefully remove any dirt clogging the charging socket using a dry, soft brush or a dry interdental brush. Only apply gentle pressure.
The parametric equalizer can be selected in the Smart Control Plus App.
Crossfeed can be selected in the Smart Control Plus App. Select between off / low / high depending on your requirements for the respective music experience.
You can use the gesture control on the touchpad to switch between active noise cancellation (ANC) and Transparency mode. To switch between the modes, tap the touchpad twice. Users can also control these via the Smart Control Plus App, which also allows them to turn the ANC on/off.
For different environments, users can select the different ANC and Transparent hearing settings using the Smart Control Plus App:
1) Manual – Full control of ANC and Transparent mode for each user’s needs.
2) Adaptive – Headphones will adjust the ANC based on the environment.
3) Off – Allows users to listen to music with no additional noise cancellation processing.
Users can optimize the listening experience for different genres of music using the parametric equalizer and crossfeed.
The battery level can be checked using three options:
1) The display on your smartphone screen (device- and OS-dependent).
2) In the Smart Control Plus App.
3) Press the multi-function button twice to hear voice prompt feedback through your headphones and/or check the LED indicator.
A complete charging cycle takes approx. 2 hours.
Fast charging provides users with an optimal runtime of 7 hours after just 10 mins of charging a near-empty battery.
Yes, users can charge-and-play the HDB 630 headphones using the supplied USB-C to USB-C cable. Third-party cables can be supported, but we recommend USB-IF certified cables to ensure optimum performance.
The firmware status can be checked in the Smart Control Plus App under Settings > Firmware
As the HDB 630 is designed for audiophiles, it incorporates a powerful parametric equalizer which enables the great degree of fine-tuning preferred by this community, without introducing a layer of audio conversion/compression.
The volume control of USB Audio device such as BTD 700 is dependent on the source and how it controls volume. Certain OS may have limitation when it comes to volume control for USB Audio Device, where volume between Source (e.g. Smartphone) and Output (Headphone) are independent.
- Try increasing the volume on your source device to maximum first, followed by your headphones (slide up to increase volume) – (Recommended for Android-based device with low volume)
- Check if a volume limiter has been turned on (e.g. ‘Reduce Loud Sound’ on iOS)
- Check in the app if Auto-Leveling / Volume Normalization has been turned on.
The track volume may depend on a few factors, but if the same exact file outputs at different volumes, this could be due to Auto-Leveling / Volume normalization.
Try turning off this function in the app settings and compare the results.
If a problem occurs..
Press and hold the multi-function button for 15 seconds.
The headphones can be reset to their default factory settings using the Smart Control Plus App, under Settings > Factory default settings.
1) Ensure the headphones are turned on even if using analog input.
2) Check the volume level on both source and headphones.
3) Try reestablishing the connection.
4) Try with a different connection.
5) Perform a soft reset if the above actions don’t work.
6) Perform a factory reset if a soft reset doesn’t work.
Try the pairing process again.
1) If pairing doesn’t work, please try pairing with another source device to verify whether this is a source or headphone issue.
2) Try resetting the headphones and pair again with the original source. If the headphones cannot pair with another source, please contact our customer service.
Try turning off Hi-Res (24-bit/96 kHz) in your Smart Control Plus App to prioritize connection stability.
1) Try moving your source device, as the transmission antenna may be covered up, reducing transmission quality.
2) If possible, move to an area with less wireless congestion.
Please check whether your source device supports both codecs.
Hi-Res mode is also not enabled by default in the Smart Control Plus App to optimize runtime. Users can change this in the Smart Control Plus App’s Settings > Resolution.
Some OS may prioritize different codecs, and users can enter Developer Mode in Android to change the default codec.
Some smart Android devices may not have aptX HD/Adaptive and/or Hi-Res mode enabled by default.
If this is not enabled on the source device, the HDB 630 will not receive a hi-res signal and in Signal Path will display accordingly.
Please refer to your smart device manufacturer’s support/guide to find out how to enable the required codec or resolution, which may be found in the Android Device Developer Mode.
1) Clean the charging socket.
2) Check the charging source.
3) Charge the rechargeable battery until the LED display lights up again (at least 30 minutes). If the rechargeable battery is completely discharged, it may take several minutes for the LED display to indicate the charging process.
Always store the headphones with an optimal charge level (e.g. 80%) and perform regular charging if unused for a long period to prevent deep discharge.
The headphones’ output volume is dependent on the headphone, source, and app settings.
1) The headphones’ volume can be adjusted via the touch panel and on the source (if supported).
2) Some sources may have volume limitations due to regulatory requirements. Users can review and amend this in the device’s sound settings (e.g. iOS > Settings > Sounds & Haptics > Headphone Safety > Reduce Loud Sound).
3) Some apps may apply Auto-Leveling or Volume Normalization to ensure that all music is played back at a similar level. This app may apply negative gain in most cases, affecting output volume. Changes can be made in the app’s settings.
1) Some sources may have volume limitation due to regulatory requirements. Users can review and amend this in the device’s sound settings (e.g. iOS > Settings > Sounds & Haptics > Headphone Safety > Reduce Loud Sound).
2) Some devices may have different audio implementation even if their OS are the same. This can be verified by comparing the volume across the device with same source app.
3) Some apps may apply Auto-Leveling or Volume Normalization to ensure that all music is played back at a similar level. The app may apply negative gain in most cases, affecting output volume. Changes can be made in the app’s settings.
4) Music volume may also be dependent on the audio mastering of each track. Users can test the headphones with other music to identify if this is the cause.
1) If using BTD 700 or USB Audio mode, select a higher 24-bit/96 kHz sampling rate in the sound settings
2) Try changing the USB connection or switching from the USB hub to the main device itself
3) Some apps support Exclusive Audio Mode, which allows a single app to take full control of your audio device and prevents other applications from playing sound simultaneously. This mode may help with audio performance but may disable other system sounds or notifications.
1) Please check if two devices are currently connected via the Smart Control Plus app
2) Try disconnecting one device and reconnecting the desired device
1) Disable Hi-Res mode to reduce latency
2) Use the USB Audio or Aux connection if the Bluetooth® environment is congested.
3) If connecting HDB 630 through BTD 700, triple press the button on BTD 700 to trigger gaming / low latency mode, which will scale down from 96 kHz to 48 kHz to optimize latency
1) Check the ANC settings in the app, i.e. whether transparent hearing has been turned on or if ANC has been switched off.
2) If this doesn’t work, please perform a reset and check again.
1) Check whether this is a source or device error by trying to connect the USB to another device.
2) If it works on another device, try connecting via another USB port and/or bypassing the USB Hub on the original device.
3) Try with a different USB cable (cable needs to support Data/OTG).
4) Trying cleaning the USB port or headphones.
5) Consider restarting the source devices or selecting “Forget all USB Audio Accessories” if the headphones can connect to other devices.
They should feel comfortable, with no ‘sound leaking’ that lets in outside noise or causes music distortion.
Ensure that the headphones are worn properly on your head with the microphone pointing towards your mouth.
Sennheiser offers replacement earpads and aux cables as spare parts.
The BTD 700 can be purchased as a new device from any authorized retailer.
The Sennheiser customer service contact details can be found here:
https://us.sennheiser-hearing.com/pages/contact
If you experience any problems with your device, we recommend checking for solutions in our troubleshooting guides first or, if necessary, claiming on your warranty (Service & Spare Parts):
https://spares.sennheiser-hearing.com/
In case of a warranty claim, make sure you include all original order references in your message details. Your request will be routed to your country-specific support team.
When following up on any support requests, including warranty claims, always reply to our latest e-mail. Make sure to include your request’s case reference number (marked in the e-mail’s subject line, starting with a “C”) in the subject line. This ensures that your response is properly registered in our systems.
