If you don't hear sound coming from the top speaker when you turn on the speakerphone on your U11+ phone, there might be some problem with your phone's speaker. First, check if the volume on your phone is turned on. If the volume is set too low, you may not hear sound slither io from the top speaker.
Regarding the speaker problem of U11+, if there is no sound from the upper speaker when "turning on amplification", this may not be normal. Normally both speakers should work. If the sound cracks or sounds unclear, this may mean the speaker is damaged and it may be recommended to have it repaired.
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James from James from Retro GamesRetro Games