Test the following steps:

1. Turn off the headphones and leave them off for a few minutes.
2. Delete NERO-TX in from the phone's bluetooth list.
3. Place both headphones in the box and wait 2 minutes (make sure both headphones LED lights)
4. Start searching Blue tooth units on the phone.
5. Remove both headphones from the box at the same time, make sure that both headphones are flashing.
6. Choose NERO-TX from the phone's blue tooth list. Make sure there is only a NERO-TX in the list.

You can also test this:

1. Delete the headline in all connected blue tooth lists.
2. Turn off both headphones through the button on the hearing.
3. Hold the buttons of both headphones until the headphones of the headphones blink (and say "connecting")
4. Double -click both buttons at the same time.
5. Place both headphones in the box, and then reconnect them again.

* Always use the latest version of software/operating systems (Android/iOS) in transmitting device as this reduces the risk of bugs.

If it still would not work after testing both of these variants, please send an email to support@soundbysweden.se and we will help you further from there.

Yes you can use only one headphones at a time if you want. The headphone that is not used may be placed in the charging box in the meantime. It also does not matter which of the headphones you use (right "r" or left "L") as both headphones connect separately to the phone.

If it would be that 2 NERO-TX PRO comes up in the phone's or transmitting device's Bluetooth list, it means that the headset only acts as a mono (ie right and left headphones do not sync with each other.)

In order to get the headset to act as a stereo, you need to make a reset as below:

1. Delete the headline in all connected bluetooth lists.
2. Turn off both headphones through the button on the hearing.
3. Hold the buttons of both headphones until the headphones of the headphones blink (and say "connecting")
4. Double-click both buttons at the same time.
5. Put both headphones in the box and wait 2 minutes.

Once you have made these steps:

1. Start searching for bluetooth units on the phone Bluetooth list.
2. Remove both headphones from the box.
3. Connect NERO-TX PRO in the phone's Bluetooth list. (Should only be 1 NERO-TX PRO in the list)

If it still does not work or if you need more help, you can contact support at support@soundbysweden.se and we will help you further from there.

Unfortunately, our headphones do not support multipoint, so you can only be connected to one unit at a time.

1. Activate Bluetooth on the transmitting device.

2. Press the center button on the remote control and hold it until the LED diode on the remote control comes. You then hear a voice in the headphones say ”Power on" When the diode starts to flash and switch between blue and red light, it searches for the transmitting unit with which it should be paired.

3. When you get Nitro-X in the Bluetooth list on your device, click it and the devices are connected. When the units are connected, hear the voice say "Nitro-X Connected". You can now start using your wireless headphones.

1. Delete the headset from connected bluetooth unit.
2. Turn off the connected blueting unit for 3 minutes.
3. Turn off the headphones on the headphone button.
4. Press/hold both headphones buttons at the same time until the headphones of the headphones flash.
5. Double-click both headphones buttons at the same time.
6. Place the headphones in the charging box and wait 2 minutes.
7. Pair the headline to the bluetooth unit.

Watch Video showing the entire process here!

1. Delete the headset from connected bluetooth unit.
2. Turn off the connected bluetooth unit for 3 minutes.
3. Turn off the headphones on the headphone button.
4. Press/hold both headphone buttons simultaneously until a melody comes from the hearing.
5. Place the headphones in the charging box and wait 2 minutes.
6. Pair the headline to the bluetooth unit.

Watch Video showing the entire recovery here!

Follow the following steps to restore Zero-TX:

1. In turned off mode, hold the multifunction button for 10 seconds
2. When the red and white lights shine on both headphones with a solid shine they will be turned off
3. Then put both headphones in the charge case to activate them
4. Then take them out of the case, now the extra headphone lamp should be off and the headphones go into "Pairing Mode"

Watch Video showing the entire recovery here!

If this still would not help you with your problem, send an email to support@soundbysweden.se where you describe the problem and that you tested this reset and we will help you from there.

1. Make sure the charging box is not discharged. It should be charged with the accompanying original cable to function optimally (other cables can cause conflicts in charge). When the box is charged, it blinks an LED lamp white which then turns to a solid white light when it is fully charged. If the lamp does not flash, the box will not be charged.

2. When the headphones get charging from the box lights up: one on the headset, if it should blink instead the box does not have any contact with the headline. Make sure the gold pins in the box and the gold poles are not dirty or oxidized. If they need to be cleaned, the top of a cotton swab or soft brush is recommended.

3. Also make sure you have removed the yellow tape that sits around the pins in the box when it is new, before you start charging the first time.

4. Avoid loading the box with a PD charger (fast charger), as many PD charger is not compatible with the box.

5. If the headphone's battery is fully discharged, sometimes the battery may need extra power by connecting the charger to the box and putting the headphones in the box.

If you still have problems with the charge after that, send an email to support@soundbysweden.se where you explain the problem and that you tested this and possibly what it produced for results.

• In order for the headphones to be charged in the box, there is a need of contact between the gold pins in the box and the gold poles in the headphone. You will notice that the headphones have contact if they shine red when you put it in the box. If they don't, ensure that pins and poles are clean. If they need to be cleaned, the top of a cotton swab or soft brush is recommended. Also, make sure you have removed the yellow tape that sits around the pins in the box when it is new, before you start charging the first time.
• It may also be because of the battery in the charging box is discharged. The charging box is charged by connecting the supplied cable to the charging box's USB-C input. When the box is charged, one of the four LED lights on the front should flash, which of those blinks depends on how much percent it has because each lamp indicates 25%. So the box is fully charged when all the lamps shine with a solid light.
• If you notice that the charging box does not take charge, there is most likely any problem with the cable. If you have the opportunity to test with any other USB-C cable to see if it takes charge with any other cable. Otherwise, you can send an email to support@soundbysweden.se and we will help you from there.

In order to get the best out of the sound experience, it is important that you have the right size on the pillows and that they sit right in the ears. So try out and test all the accompanying pillows to find them that suits you best. When you insert the headset start with the headline turn down and then turn it 90 degrees to the correct position.

PD = Power Delivery and is available in USB-C fast chargers from 15 up to 100W. Unfortunately, NiTRO-X cannot receive a charge if a charger has this chip in itself, because the electronics in the headphone will then end up in conflict.

Note! We also do not recommend using these chargers on our other headphones, as they can be damaged by charging with chargers with this chip.

If the battery in the charging box is not charged, the headphones will not turn off automatically when you put them down. The headphone's LED should glow with a steady light to indicate that it has contact with the box and then turn itself off. If the LED on the earphone flashes, it has no contact with the box and then does not switch off by itself.

So try to upload the box and test again! Should it still not work, send an email to support@soundbysweden.se and we will help you from there.

This is very likely that dirt/ear wax has been entered on the inside of the grid. Clean the grid by gently brushing with a fine -threaded brush (eg toothbrush). If this does not help, you can moisten a tops with hydrogen peroxide (max 3%) and gently iron it over the grid and let it work for 30 seconds. Then use the brush again and brush gently on the grill. It is important that you do not take too much hydrogen peroxide (max 3%) on the tops so that it flows into the headphone chassis itself and destroys the speaker element.

If the sound does not return to normal after following the cleaning instruction above, it is recommended that the speaker grill be dismantled*. Note! Take the utmost care in when dismantling so that the grid or speaker element does not take damage. The grid is fixed with a fastener which allows re -mounting. Use a needle or other thinly sharp object to disassemble the grid and clean it with a dry brush. Then reassemble the grid by gently pressing it in its place.

*The grid on the headphone model NiTRO can be screwed off unlike other models. Unscrew the grid and clean with household soap and lukewarm water. Be sure that the grid is dry before screwed back on headline.

If you consider the sound too low with Nero USB-C, it may be that the phone (Android devices) has set up automatically on a sound limit for the headphones. This can be changed in the phone's settings: Open Settings and press "Sounds and Features", then look for "sound effects" and check if the setting of the "headphone sound limit when playing" is turned on, then turn it off.

Should it already be rejected or that it did not help to turn it off but the sound is still low, email us at support@soundbysweden.se and we will help you from there!

If you experience bad microphone sounds during calls, please test this.

1. Turn off the phone for 3 min
2. Restart the phone and delete device (model name) in the list of connected Bluetooth devices.
3. Pair the headphone with the phone.
4. Try calling via wifi call or by app ex. Skype, WhatsApp and others to ensure that it is not about poor mobile coverage. NOTE ZOOM, Teams and others have a number of bugs - go into settings - Set quality of audio/image transfer.
5. Try just using one headphones at a time and see if there is any hardware failure on, for example, the microphones on the right or left side.

If you still have problems after that, contact Support on support@soundbysweden.se , also mention that you tested this.

If you have a phone with a 3.5mm port then the microphone with Nero does not work to the USB-C port, as it becomes like a blockage because the microphone on those units should actually come through the 3.5mm port. So if you use Nero-USB on a device that also has a 3.5mm port then you will only be able to use the headphones for music listening and not as a microphone during conversation.

On some phones you can make an update that makes this work anyway, here is a good video showing how to do with a Samsung phone: https://www.youtube.com/watch?v=no15gU4KX74

Samsung that works with calls and music: A53/A33/M53/S22 ULTRA/S22+/S21/S21+/S21 ULTRA/S21 FE/S20 FE/S20/S20 ULTRA/S20+/Note 20 Ultra/Note 20/Z FOLD4 3/ Z Flip/ Fold 5/ Filp5

Samsung Galaxy A32 works only for music playback.

If you have an Android phone, this is usually due to your device changing audio codec automatically to something that does not support. Then change instead to audio codec SBC or AAC, so it should work better. This is done in different ways depending on what you use for device, but it can be done through your phone's settings. If you do not find so try to google, you should probably get a guide you can follow.

If you need more help, you can always contact us via email at support@soundbysweden.se and we will help you from there!

If you feel that the sound is hacking from time to time, it is probably due to the signal between the headphone and the transmitting device in some way. There may also be surrounding factors such as household appliances, power lines or other wireless units that interfere with the signal. Also note that the bluetooth signal between the units becomes weaker in an outdoor environment compared to indoors.

The range of most Bluetooth devices is about 10m. However, optimal reach for this type of signal transfer is shorter than that. If you feel that the sound is chopping, you can try moving the devices closer together. For example, if you have the phone in the right back pocket, try to move it to the left front pocket so that the signal between the phone and the hearing will be the shortest possible as the headphone Bluetooth antenna is located in the remote control. You can also try restarting the headphone, restoring the pair with the transmitting device and then again pairing the headset with the transmitter unit.

iOS devices show the headphones battery level using a battery symbol in the display. The symbol is located next to the unit's own battery symbol.

For Android devices you need to go in through Settings and Connected units To find out the headphone's battery level. You also download any of the apps Bluetooth Battery Indicator or Bluetooth headset battery in the Google Play Store, to easily monitor the level.

When the headphones' battery level comes down to 10%, you hear a voice in the hearing say "Battery low" and it will then be time to charge the headphones.

• Make sure the slider (switch) on the back of the remote control is in the correct position for the operating system that your device uses.
Location 1 - Android and Windows
Mode 2 - iOS (Apple)

• Make sure the 3.5mm contact is properly pressed into the device so that it does not slip. Check this especially if you have a mobile shell on your smartphone as this may be in the way for the contact to be fully pressed.

• Verify that your smartphone is compatible with the remote control. 

This is very likely that you have not found the right size of the headphone pads. The package contains earphone cushions of different sizes and materials. Try you until you find a dense and comfortable fit for best sound experience. Also, ensure that you insert the headline properly. Start with the headset downwards and then turn it 90 degrees to the correct position.

This is a well-known phenomenon that can occur when inserting an in-ear headphones into the ear canal and it is usually referred to as "drives flex". What happens is that the overpressure that is formed when pressing in the headset is pressed past the speaker element so that this can be fluctuated which can cause a snapping/clicking metallic sound. This is not something that damages neither hearing nor headphones and is perfectly normal as you have been given a close fitting of the hearing in the ear canal.

You should not use a different charging cable than the one that follows in the package. The accompanying cable has a built -in overload protection and therefore cannot be replaced with a "standard cable". If you are using another cable, you risk destroying the headphones as the current can be too high.

If losing away or would have the cable, you can order new here.

You can find each headphone model's manual at the bottom of the respective product page.

If you were to lose some such as charging case or charging cable so it is possible to order directly here. Should there be anything else you have lost that you will not find on this page so send an email to support@soundbysweden.se with what you missand we will see if it can be solved.

Note! Since each headphone pair has a common unique ID, it is not possible to connect a new headphones to these, and therefore unfortunately it is not possible to order only one headphone in case you have lost one of them.