[Trac #711] New ALSA mixer setting is needed

[Zarro Boogs per Child]

#711: New ALSA mixer setting is needed
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 Reporter:  Nat     |        Owner:  Nat     
     Type:  defect  |       Status:  reopened
 Priority:  high    |    Milestone:  BTest-3 
Component:  distro  |   Resolution:          
 Keywords:          |  
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Changes (by rsmith):

  * priority:  normal => high
  * status:  closed => reopened
  * resolution:  fixed =>

Comment:

 I'm reopening this ticket because as of build 239 it's still not fixed

 In the process of working out the Mic issues with B2 I have determined the
 source of the feedback.

 As Nat stated earlier, the mic volume control is for the mic analog mixer
 back out into the output stream.  We currently have it defaulting to about
 3/4 of full scale.  So when you unmute that control you get feedback from
 speaker into the mic.  Resulting in the high pitch squeal.  Lowering the
 mic mixer volume or muting the channel stops the feedback.

 This control does not have any effect on the recording level which is set
 in a different control.

 We need to make the default value of this control zero and leave its
 channel muted.

 The only time mic->speaker analog mixer feedthrough is needed is when you
 have a headset. A slight amount of feedthrough is comforting and helps to
 keep the user from speaking too loud into the mic since they can hear
 themselves in the headphones.

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Ticket URL: <http://dev.laptop.org/ticket/711#comment:7>
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