#9641 NORM 1.5-sof: test XO-1.5 audio recording levels

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#9641: test XO-1.5 audio recording levels
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           Reporter:  dsd       |       Owner:  dsd                              
               Type:  task      |      Status:  new                              
           Priority:  normal    |   Milestone:  1.5-software-later               
          Component:  kernel    |     Version:  Development build as of this date
         Resolution:            |    Keywords:                                   
        Next_action:  testcase  |    Verified:  0                                
Deployment_affected:            |   Blockedby:  9639                             
           Blocking:            |  
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Comment(by Quozl):

 Tested using a recorder (a woodwind musical instrument) and the ALSA
 utilities arecord and aplay.

 On XO-1 build 802 and XO-1.5 build os200.

 The laptops were set side by side in a quiet location, equidistant from
 the sound source.  The output volume control on each laptop was raised to
 maximum using the volume up key on the keyboard.

 Commands used in Terminal:

 {{{
 arecord --vumeter=mono --rate 44100 /tmp/test.wav
 aplay /tmp/test.wav
 }}}

 There was no obvious difference in the volume meter readings during
 recording of the sound.  (There was a pulse of energy at the start of the
 XO-1 recording in the silence before the musical instrument was not
 active.)

 There was no audible difference in the recordings when played back.

 Conclusion: the signal path from air through to user space via ALSA is
 clean and at near identical levels between the laptops.

 Hardware, driver, kernel, ALSA are all good.  Anything we find in the
 Record activity is probably unrelated.

-- 
Ticket URL: <http://dev.laptop.org/ticket/9641#comment:6>
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