There is a constant slightly-squeaky soft white noise coming from my headphones on all the versions of Linux I've tried on my laptop (Linux Mint 16, Archbang, Opensuse 13.1, Fedora 20). It seems that:
- if I *unmute* the microphone output on alsamixer, the squeakiness (which sounds like Tinnitus) goes away, although the white noise is still there.
- if I mute the headphone channel or the main channel, the noise goes away.
- the loudness of the noise is not affected by the volume level of any channel.
- the noise does not go away if I unplug my laptop charger.
- the noise cannot be heard from the laptop speakers.
Also, my laptop is (was) a dual-boot with Windows 8.1. There was a similar problem with the headphones on Windows (although slightly less louder if I remember right). The problem went away after I updated my audio driver to Realtek High Definition Audio 18.104.22.16883 from the ASUS N550JV support website.
Things that may be relevant:
- The sound card is Realtek ALC668, I believe.
- This laptop has the headphones and mic jack in the same.. jack.
- As an aside: ALSA selects the HDMI output (with non-changeable zero SPDIF volume levels) as default, even though it doesn't play anything. It also strangely calls both audio outputs as snd_hda_intel, which can lead to confusion in selecting the default sound card on the ALSA config file.
our powerful speakers create immersive sound, tuned by the ASUS Golden Ear team. The quad-speaker array shapes sound and ensures best-reproduction and delivery. Beamforming and crosstalk cancellation join Head-Related Transfer Function (HRTF) technology to clear up audio, remove interference
what is quad speaker array ?
do it have four internal speakers using 4 channels if it can use crosstalk cancellation and HRTF ?
Node 0x0e [Audio Mixer] wcaps 0x20010b: Stereo Amp-In
Amp-In caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
Amp-In vals: [0x00 0x00] [0x80 0x80]
does it help if you mute the input from audio mixer 0x0b into node 0x0e ?
seem four speakers at the front bottom of the laptop
Yes, it's four speakers and an external subwoofer. Not sure about muting the audio mixer node.
If it helps, there was a recent bug concerning the same sound system, where the subwoofer wasn't working. It was fixed in 3.13-rc1:
do you mean four speakers only use stereo ?
do all four speakers playback sound ?
do you mean the two speakers at the left playback the left channel and the two speakers at the right playback the right channel ?
how do the speakers works windows ?
when audio wizzard
1) music mode
2) movies mode
3) record mode
4) gaming mode
5) speech mode
Do maxxaudio support 5.1 or 7.1 downmix playback ?
are there any differences of the sound in four speakers in wide mode and the other modes ?
Created attachment 127171 [details]
maxxaudio on windows
MaxxVolume uses a powerful combination of high level compression to increase RMS levels, low level compression to increase the clarity of soft sounds, and noise gating to eliminate signal and system noise
does the sub woofer need low pass filter ?
It seems you can adjust the low cutoff frequency with the maxxaudio control panel, so I think it uses a low pass filter. Here's specifics: http://www.maxx.com/objects/PDF/MaxxAudio%20Master%20for%20Asus%20N-Series%20User%20Guide.pdf
I would guess that the sub woofer needs a low pass filter, since when I got it working on linux, you could hear more than just the bass.
are there any difference in surround 2.1
SonicMaster Lite powerful audio with built-in subwoofer
vt1802 is only 4 channels
alc663 is 6 channels
SonicMaster Premium with stereo speakers with external subwoofer
3) your N550JV
SonicMaster Preium with quad-speaker array and external subwoofer
alc668 is 6 channels
do you mean quad speaker array are working as same as in windows ?
pulseaudio don't provide low pass filter for LFE channel
you also need hack in driver if surround21 need 6 channel if quad speaker array only need stereo
you can try automute via amp instead of pinctl