popping noise in wireless headphones

Discussion in 'The Projects Forum' started by slipstick, Jul 7, 2006.

  1. slipstick

    Thread Starter New Member

    Jul 6, 2006
    6
    0
    Hello.
    My Philips wireless headphones (SBC HC8435) work well most of the time. But at the edge of their range, I hear popping noises that are MUCH LOUDER than the music I'm listening to.

    Is there a circuit I could insert (between reciever and speakers) to normalize the volume or filter out the pops?

    thanks!
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Which edge? If it's the upper range of response, you might have an emphasis problem in the transmitter. If the lower, it might be something mechanical in the headphone driver element. Does it still happen when you go some distance away fron the transmitter?
     
  3. slipstick

    Thread Starter New Member

    Jul 6, 2006
    6
    0
    I think I chose the wrong word. By "range" I meant how far away from the transmitter the headphones will work.

    When I'm in the same room as the transmitter everything sounds good. No pops. But as I move away from the transmitter I start to hear pops mixed with the music.

    Distance from transmitter : What I hear
    10 feet : NO POPS. Music quality is like a strong FM station.
    20 feet : SOME POPS. Music is OK.
    30 feet : MANY POPS. Music fades away.
     
  4. slipstick

    Thread Starter New Member

    Jul 6, 2006
    6
    0
    I figured out the cause:
    When the carrier wave becomes too weak, a circuit inside the headphones turns off the amplifier (to conserve battery power). The POP is when the amplifier is shut down.
     
  5. Pelleman

    New Member

    Dec 18, 2006
    1
    0
    I also have this problem on my SHC8525. It even pops then I watch movies. The sound is wery dynamic in moves today, going from speach to music is a dramatic change of soundlevel. I guess that the sound reduction circuit in the FM reciever doesn't like this (there is a name on this circuit?). The tecnique is used in many FM radios today but it might requre the heavily compressed sound that is used in broadcasts.

    Slipstick: the amplifier is normally turned off after one silent minute, but if the signal is lost the amp is turned off immediatly (tested by turning off the transmitter and changing frequency).
     
  6. Nekura

    New Member

    Jun 26, 2007
    1
    0
    I also have these headphones, but my problem is a little bit more pronounced.

    I am getting no sound at all from the headphones when I have them turned on, not even static hiss or white noise. The base station's red light is on, indicating that signal is being sent, and the headset's red light is on also, meaning that it is receiving power. None of the 3 available channels produce any different result.

    I should also mention that the range (distance) I'm working at is less than a metre, and without obstructions. Further to this, I tried tuning another set of wireless headphones in to receive the signal my base unit was transmitting. I could hear it just fine on this other set of headphones.

    This leads to me think that the problem is with my headset. I called Philips customer care and all they could suggest was to take the headphones back to the retailer. This isn't possible since I bought them privately.

    Any suggestions would be much appreciated!
     
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