Thread: Audio, PA, XPROT, and the damage done
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joerg_rw is offline joerg_rw
2013-09-10 , 15:01
Posts: 2,222 | Thanked: 12,651 times | Joined on Mar 2010 @ SOL 3
#1
Originally Posted by electroaudio View Post
A decent line-out, without class-D amplifier and speakerprotection in the signalchain would also be nice, i cant use my n900 now as a soundsource for professional work since the sound is just too weird.
Indeed it seems it's XPROT and the gear around it that got invented (or at least adopted) by Nokia when it became obvious the class-D without highpass would blow their speakers, which now has some quite unpleasant effects on audio, like dynamic compression, dynamic EQ and other crippling of high quality audio.
Though all this might be needed and maybe even OK for the built in speakers, it's probably worth it to review and rework the sw-side audio chain when using headset connector, particularly when using it for 0dB line-out to any home-stereo or even professional equipment. Alas it's not possible to auto-detect whether headphones or a 3.5mm->2*cinch Line-In cable is connected, so any such adjustment has to happen by triggering it from a sort of GUI.

For first experiments it might be worth it to completely shut down PulseAudio and use the plain ALSA for audio output. CAVEAT: this scenario is known to potentially blow your speakers in N900.

PS: I don't think the class-D amp by itself is that bad.
Cheers
jOERG
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