1 Dec 2007 06:00
Re: iBook clamshell audio
Masafumi Hotta <ma-500 <at> khaki.plala.or.jp>
2007-12-01 05:00:27 GMT
2007-12-01 05:00:27 GMT
Hello. I enjoyed the test and it worked fine on my iBook. First I tried with the internal speaker playing WAV file with audioplay. But there was no sound at all. Then I set the volume with mixerctl up to 250,250 (default is 80,80). I could listen to the sound putting my ear on the speaker. I think it is no good because 250,250 is the maximum level. Next plugging stereo headphones, it worked with no problems. Setting the volume to 80,80 again, it was enough to use with my headphones, and 250,250 was to much. I could see the message on the shell. " i2s0: powering down dac3550a0: entering low power mode" I'm looking forward the next time to test. Thank you. Masafumi Hotta
monitor.output=speaker { speaker headphones line }
monitor.master=80,80 volume
record.record=0,0 volume
monitor.treble=128,0
monitor.bass=128,0
(Continue reading)
> Setting the volume to 80,80 again, it was enough to use with my
> headphones, and 250,250 was to much.
Yes, 250 is expected to be a high volume. It corresponds to +18 dB.
The 0 dB point corresponds to value 176, so this should be the highest
possible value that can be used without distortion. The value of 80
corresponds to -36 dB.
Thinking about this, it would be nice if mixerctl(1) could use dB
values instead of the 0-255 scale; this would be good for consistency
between different audio devices.
RSS Feed