HD 450BT Around-ear headphones Model: SEBT4 Instruction manual Use the search function, the navigation (left) or the following links: Start “Product overview” “Getting started” “Using the headphones” “FAQ/If a problem occurs ...” “Specifications” Sennheiser electronic GmbH & Co. KG Am Labor 1 30900 Wedemark Germany www.sennheiser.
Important safety instructions Important safety instructions ▷ Read this instruction manual carefully and completely before using the product. ▷ Always include this instruction manual when passing the product on to third parties. ▷ Do not use the product if it is obviously defective or makes loud, unusual (whistling or beeping) noise. ▷ Only use the product in environments where Bluetooth® wireless transmission is permitted.
Important safety instructions Only use rechargeable batteries and chargers recommended by Sennheiser. Only charge the product / rechargeable batteries at ambient temperatures between +10 °C to +40 °C/50 °F to 104 °F. Do not heat the product / rechargeable batteries above +70 °C/140 °F. Avoid exposure to sunlight and do not throw the product / rechargeable batteries into fire. When not using the product / rechargeable batteries for extended periods of time, charge them regularly (about every three months).
Important safety instructions Intended use/Liability These headphones have been designed as an accessory for Bluetooth compliant devices. They are intended for wireless audio communication such as music playback and phone calls via Bluetooth wireless technology. It is considered improper use when the product is used for any application not named in the corresponding product documentation.
Package contents Package contents HD 450BT around-ear headphones Model: SEBT4 USB charging cable with USB-C and USB-A connector Analog audio cable with 3.5 mm jack plug and 2.5 mm jack plug, length approx. 1.5 m Carry case Quick guide Safety guide Online you can find: • this detailed instruction manual and additional information www.sennheiser.com/download • the Sennheiser Smart Control app for configuring the headphones and for additional functions www.sennheiser.
Product overview Product overview HD 450BT model: SEBT4 1 2 2 3 Left L B Right R C A 0 9 8 7 6 4 5 Headband Ear cup joints Ear cups, steplessly adjustable On/off button for the headphones and the active noise cancellation ANC pressing for 4 seconds activates the Bluetooth pairing mode pressing 1x activates/deactivates ANC LED Input for analog audio cable; when a cable is connected, flight mode is activated/Bluetooth is deactivated USB-C socket for charging 6 | HD 450BT
Product overview Volume – button (volume down) Volume + button (volume up) 3-way multi-function button for music and call functions Voice assistant button Ear pads Speech microphones (2 pcs.
Product overview Notes on voice prompts The headphones output voice prompts for various functions (see examples below).
Getting started Getting started 1. Charging the rechargeable battery The headphones' rechargeable battery is not fully charged upon delivery. Before using the headphones for the first time, charge the rechargeable battery for a complete charging cycle without interruption (> 11). USB-C USB-A 2. Installing the Smart Control app on your smartphone The Sennheiser Smart Control app allows you to use all functions and settings of the headphones and to e.g.
Getting started 4. Putting the headphones on and adjusting the headband For good sound quality and best possible wearing comfort, the headband can be adjusted to properly fit your head (> 17).
Using the headphones Using the headphones Information on the rechargeable battery and the charging process The headphones have a built-in rechargeable battery. A complete charging cycle takes approx. 2 hours. Before using the headphones for the first time, charge the rechargeable battery for a complete charging cycle without interruption. When the headphones are being charged, the LED lights up (> 7). Once the headphones are fully charged, the LED flashes blue for 5 minutes and then goes off.
Using the headphones LED Meaning lights up red flashes blue for 5 minutes, for 5 min the LED then goes off Rechargeable battery is being charged Rechargeable battery is fully charged LED Off If the LED does not light up immediately during charging, clean the charging socket and charge the headphones until the LED lights up again (> 11). You can speed up the charging process by charging the headphones when they are switched off.
Using the headphones Paired and connected Bluetooth device Paired Bluetooth device (currently not connected) HD 450BT | 13
Using the headphones Pairing the headphones with a Bluetooth device 1. Switch the headphones off and place them close to the Bluetooth device (max. 20 cm). 2. Press and hold the on/off button for 4 seconds. The LED flashes red and blue. The headphones are in pairing mode. 3. Activate Bluetooth on your Bluetooth device. 4. Via the menu of your Bluetooth device, start the search for new Bluetooth devices. All active Bluetooth devices in the proximity of your Bluetooth device are displayed. 5.
Using the headphones Disconnecting the headphones from a Bluetooth device ▷ Via the menu of your Bluetooth device, disconnect the connection to the headphones. The headphones are disconnected from the Bluetooth device. You hear the voice prompt “Lost connection”. The headphones switch to standby mode. To delete the Bluetooth pairing list of the headphones, > 31.
Using the headphones Switching the headphones on WARNING Danger of hearing damage due to high volume levels! Listening at high volume levels can lead to permanent hearing defects. ▷ Before putting the headphones on, adjust the volume to a low level (> 19). ▷ Do not continuously expose yourself to high volume levels. 1. Unfold both ear cups. The joints click into place. 2. Press and hold the on/off button for 2 seconds. The LED flashes blue 3x. You hear the voice prompt “Power on”.
Using the headphones Switching the headphones off 1. Press and hold the on/off button for 2 seconds. 2. You hear the voice prompt “Power off” and the LED flashes red 3x. The headphones switch off. 2 1 “Power off“ Hold 2s Putting the headphones on and adjusting the headband For good sound quality and best possible wearing comfort, the headband can be adjusted to properly fit your head. ▷ Wear the headphones so that the headband runs over the top of your head.
Using the headphones Retrieving information on the battery charge status When the headphones are connected to your Bluetooth device, the battery charge status can be displayed on the screen of your smartphone (depending on the device and operating system used). The Smart Control app also displays the battery charge status. You can retrieve information on the battery charge status on the headphones by pressing the center of the volume button 1x.
Using the headphones Adjusting the volume WARNING Danger of hearing damage due to high volume levels! Listening at high volume levels can lead to permanent hearing defects. Toggling between the audio sources may cause enormous volume jumps that can permanently damage your hearing. ▷ Before putting the headphones on and before toggling between audio sources, adjust the volume to a low level. ▷ Do not continuously expose yourself to high volume levels.
Using the headphones Information on active noise cancellation ANC Due to its closed design, the headphones offer effective passive isolation from ambient noise. In addition, the headphones have an active noise cancellation (ANC) function, which allows you to reduce ambient noise to a minimum. Even when ANC is activated, your headphones' sound quality is always at its best.
Using the headphones ANC ON LED Active Noise ON Cancellation 3x ON 1x OFF ON Active Noise Cancellation ON ANC OFF LED Active Noise OFF Cancellation 3x ON 1x OFF ON Active Noise Cancellation OFF OFF Listening to music using the headphones You can listen to music when the headphones and your audio source are connected via Bluetooth (> 12) or the audio cable (> 26).
Using the headphones 3-way multi-function button Slide backwards Function Plays the next track in the playlist Playing the previous track ▷ Slide the 3-way multi-function button forwards.
Using the headphones Making phone calls using the headphones The following call functions are only available when the headphones and smartphone are connected via Bluetooth. Some smartphones or communication apps may not support all functions. Making a call ▷ Dial the desired number on your smartphone. If your smartphone does not automatically transfer the call to the headphones, select “HD 450BT” as the output device on your smartphone (see the instruction manual of your smartphone if necessary).
Using the headphones 3-way multi-function button Function 24 | HD 450BT Press 2x Ends the active call and accepts an incoming call Press 2x Toggles between active call and call on hold
Using the headphones Using the voice assistant/voice dialing ▷ Press the voice assistant button once. The available voice assistant of your smartphone is activated (depending on the system or app on your smartphone: Siri, Google Assistant, or others. If no voice assistant is available, voice dialing may be activated). ▷ Ask the voice assistant your question or make a request. Right R 1x To cancel the voice assistant/voice dialing: ▷ Press the voice assistant button 1x.
Using the headphones Connecting the headphones using the audio cable 1. Insert the 2.5 mm jack plug of the audio cable straight into the headphones' audio socket until you feel a resistance. 2. Turn the 2.5 mm jack plug to the right until you feel a resistance. The jack plug is now locked in place and the audio cable is correctly connected to the headphones. 3. Insert the 3.5 mm jack plug of the audio cable into the audio output of your smartphone. The Bluetooth connection is deactivated.
Using the headphones Storing and transporting the headphones Store the headphones in the carry case to prevent damage to the headphones when you are not using or transporting them. ▷ Fold up the headphones and place them in the carry case as shown in the illustration.
Care and maintenance Care and maintenance CAUTION Liquids can damage the electronics of the product! Liquids entering the housing of the product can cause a short-circuit and damage the electronics. ▷ Keep all liquids far away from the product. ▷ Do not use any solvents or cleansing agents. ▷ Clean the parts of the product only with a soft, dry cloth. Replacing the ear pads For reasons of hygiene, you should replace the ear pads from time to time.
Care and maintenance Installing firmware updates Firmware updates can be downloaded free of charge from the Internet using the Sennheiser Smart Control app. Sennheiser recommends to always install the latest firmware version to ensure the best performance of your product. ▷ Connect the headphones to your smartphone and start the Smart Control app (> 15). ▷ The app provides information on available firmware updates and guides you through the installation process.
FAQ/If a problem occurs ... FAQ/If a problem occurs ... Current list of frequently asked questions (FAQ) Visit the HD 450BT product page at www.sennheiser.com/download There you will find a current list of frequently asked questions (FAQ) and suggested solutions. Your question has not been answered or the problem persists? If a problem occurs that is not listed in the FAQ section or if the problem cannot be solved with the proposed solutions, please contact your Sennheiser partner for assistance.
FAQ/If a problem occurs ... Deleting the Bluetooth pairing list of the headphones Make sure that no audio cable is connected to the headphones and that Bluetooth is activated (> 26). 1. Switch off the headphones (press and hold the on/off button for 2 seconds) and then start pairing mode (press and hold the on/off button for 4 seconds) (> 17 and 14). 2. Simultaneously press and hold the on/off button and the 3-way multi-function button for 3 seconds. The LED flashes purple 3x.
FAQ/If a problem occurs ... When using the analog audio cable, the music only plays on one side of the headphones The jack plug of the audio cable is not properly locked in place in the headphones' audio socket: 1. Insert the 2.5 mm jack plug of the audio cable straight into the headphones' audio socket until you feel a resistance. 2. Turn the 2.5 mm jack plug to the right until you feel a resistance. The jack plug is now locked in place and the audio cable is correctly connected to the headphones. 3.
Specifications Specifications Model: SEBT4 Wearing style Bluetooth® around-ear, closed-back Ear coupling circum-aural Transducer principle dynamic Transducer 32 mm Frequency response 18 Hz to 22,000 Hz (-10 dB) Sound pressure level (SPL) 108 dB (1 kHz/0 dBFS) THD (1 kHz, 100 dB SPL) < 0.
Manufacturer Declarations Manufacturer Declarations Warranty Sennheiser electronic GmbH & Co. KG gives a warranty of 24 months on this product. For the current warranty conditions, please visit our website at www.sennheiser.com or contact your Sennheiser partner.
Manufacturer Declarations aptX is a trademark of Qualcomm Technologies International, Ltd., registered in the United States and other countries, used with permission. Other product and company names mentioned in the user documentation may be the trademarks or registered trademarks of their respective holders.
