[USB-Audio - Razer Megalodon, playback] Underruns, dropouts or crackling sound

[James Balnaves]

Happens in all apps. Only when audio is playing.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: pulseaudio 1:3.0-0ubuntu6
ProcVersionSignature: Ubuntu 3.8.0-21.32-generic 3.8.8
Uname: Linux 3.8.0-21-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.9.2-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC2: james 2384 F.... pulseaudio
 /dev/snd/controlC1: james 2384 F.... pulseaudio
 /dev/snd/controlC0: james 2384 F.... pulseaudio
Date: Fri May 24 15:32:18 2013
InstallationDate: Installed on 2012-08-03 (294 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: pulseaudio
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:Megalodon successful
Symptom_Card: Razer Megalodon - Razer Megalodon
Symptom_PulsePlaybackTest: PulseAudio playback test failed
Symptom_Type: Underruns, dropouts, or "crackling" sound
Title: [USB-Audio - Razer Megalodon, playback] Underruns, dropouts or crackling sound
UpgradeStatus: Upgraded to raring on 2013-05-23 (1 days ago)
dmi.bios.date: 11/22/2012
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P2.70
dmi.board.name: X79 Extreme4-M
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP2.70:bd11/22/2012:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnX79Extreme4-M:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Arkadiusz Piekarz (piekarzarkadiusz)]

I noticed if you switch playback profiles multiple times (from 5.1 to 7.1 and back again), it will eventually work properly without crackling. However, after some time or a restart it breaks again. This problem occurred also in Ubuntu 12.04, 12.10 and Kubuntu.

[John McKackingder (reportados123)]

I also have this problem, I have Arch Linux installed and my headset would crackle no matter what configuration I set, I tried all the possible workarounds/fixes and still nothing. I tried ALSA and PulseAudio but I always get crackling. On a rare occasion, I would get perfect sound with no crackling, and then after you reboot, it's gone back to crackling. Also, every time I listen to any kind of music/video/sound, after a period of time, the Razer Megalodon would just freeze and I would have to replug it back in to fix it (which crackling still occurs). I tried many different distros on a livecd and all of them would cause crackling. This is a problem with ALSA, and I'd appreciate if anyone could fix this problem.

[Kaito (kaito-linux)]

Hey, I´m an suse user with exactly the Same Problem.

I got completely the same issue as reportados123, but i found a (not complete) "fix"!

I searched about this thing for Weeks and get stuck at the snd_usb_audio kernel module.

I noticed the 'nrpacks' parameter of this module and start to play with it... and finally.... NO CRACKS.

The Sound was fixed. But the Microphone get sometimes really worse like squeaking sounds or high Pitch.

But in most use cases it works just perfectly.

Here is what to do (I use opensuse 12.3, so i don’t know if it works for you..)

1. Stop any Application that uses ALSA or Pulse.

2. Open a Root shell (su, or sudo su)

3. type "killall pulseaudio" in your Terminal Emulator so long if it stops for auto spawn (yes, i know dirty but i´m lazy)

4. unload 'snd_usb_audio' with "rmmod snd_usb_audio".

5. Create an configuration file for 'snd_usb_audio' in /etc/modprobe.d/

echo "options snd-usb-audio nrpacks=16" > /etc/modprobe.d/audio-force.conf

Note: For me works '16' as the Best Value. .

6. Now load 'snd_usb_audio' again: "modprobe snd_usb_audio"

7. Start pulseaudio again or just relog/boot.

I hope it helps anyone!

p.s: sry my english sucks :p (from germany)

[Arkadiusz Piekarz (piekarzarkadiusz)]

Kaito (kaito-linux), I'm sorry but your advices didn't fix the problem on Kubuntu 13.04. The sound still crackles.

[Raymond (superquad-vortex2)]

do your 7.1 headset support stereo ?

pot the pulseaudio verbose log

https://wiki.ubuntu.com/PulseAudio/Log

lsusb -vvvv

  device.bus = "usb"
  device.vendor.id = "1532"
  device.vendor.name = "Razer USA, Ltd"
  device.product.id = "000e"
  device.product.name = "Razer Megalodon"
  device.serial = "Razer_Razer_Megalodon"
  device.string = "2"
  device.description = "Razer Megalodon"
  module-udev-detect.discovered = "1"
  device.icon_name = "audio-card-usb"
 profiles:
  input:analog-mono: Analog Mono Input (priority 1)
  output:analog-surround-41: Analog Surround 4.1 Output (priority 800)
  output:analog-surround-41+input:analog-mono: Analog Surround 4.1 Output + Analog Mono Input (priority 801)
  output:analog-surround-50: Analog Surround 5.0 Output (priority 700)
  output:analog-surround-50+input:analog-mono: Analog Surround 5.0 Output + Analog Mono Input (priority 701)
  output:analog-surround-51: Analog Surround 5.1 Output (priority 800)
  output:analog-surround-51+input:analog-mono: Analog Surround 5.1 Output + Analog Mono Input (priority 801)
  output:analog-surround-71: Analog Surround 7.1 Output (priority 700)
  output:analog-surround-71+input:analog-mono: Analog Surround 7.1 Output + Analog Mono Input (priority 701)
  off: Off (priority 0)
 active profile: <output:analog-surround-71+input:analog-mono>
 sinks:
  alsa_output.usb-Razer_Razer_Megalodon-00-Megalodon.analog-surround-71/#1: Razer Megalodon Analog Surround 7.1
 sources:
  alsa_output.usb-Razer_Razer_Megalodon-00-Megalodon.analog-surround-71.monitor/#1: Monitor of Razer Megalodon Analog Surround 7.1
  alsa_input.usb-Razer_Razer_Megalodon-00-Megalodon.analog-mono/#2: Razer Megalodon Analog Mono
 ports:
  analog-output: Analog Output (priority 9900, latency offset 0 usec, available: unknown)
   properties:

do your headset have volume control at the audio processing unit ?

http://www.razerzone.com/gaming-audio/razer-megalodon/

!!-------Mixer controls for card 2 [Megalodon]

Card hw:2 'Megalodon'/'Razer Razer Megalodon at usb-0000:00:1d.0-1.2.1.1, full speed'
  Mixer name : 'USB Mixer'
  Components : 'USB1532:000e'
  Controls : 2
  Simple ctrls : 1
Simple mixer control 'PCM',0
  Capabilities: pswitch pswitch-joined penum
  Playback channels: Mono
  Mono: Playback [on]

[Arkadiusz Piekarz (piekarzarkadiusz)]

Hi Raymond,

> do your 7.1 headset support stereo ?
Its external sound card has a switch for 2.0/7.1 speaker configuration, so I guess it does.

> pot the pulseaudio verbose log
I'll attach it below this comment. I launched Amarok and played a song for a couple seconds, heard crackling and paused it.

> lsusb -vvvv
Attached below.

> do your headset have volume control at the audio processing unit ?
That is correct.

If you want more info, I'll be glad to provide it.

[Raymond (superquad-vortex2)]

do you mean the log was obtained when you switch to 7.1 since there is no stereo ?

the card only support 48000Hz

6 or 8 channels playback

      AudioStreaming Interface Descriptor:
        bLength 11
        bDescriptorType 36
        bDescriptorSubtype 2 (FORMAT_TYPE)
        bFormatType 1 (FORMAT_TYPE_I)
        bNrChannels 1
        bSubframeSize 2
        bBitResolution 16
        bSamFreqType 1 Discrete
        tSamFreq[ 0] 48000

      AudioStreaming Interface Descriptor:
        bLength 11
        bDescriptorType 36
        bDescriptorSubtype 2 (FORMAT_TYPE)
        bFormatType 1 (FORMAT_TYPE_I)
        bNrChannels 8
        bSubframeSize 2
        bBitResolution 16
        bSamFreqType 1 Discrete
        tSamFreq[ 0] 48000

AudioStreaming Interface Descriptor:
        bLength 11
        bDescriptorType 36
        bDescriptorSubtype 2 (FORMAT_TYPE)
        bFormatType 1 (FORMAT_TYPE_I)
        bNrChannels 6
        bSubframeSize 2
        bBitResolution 16
        bSamFreqType 1 Discrete
        tSamFreq[ 0] 48000

     AudioControl Interface Descriptor:
        bLength 12
        bDescriptorType 36
        bDescriptorSubtype 2 (INPUT_TERMINAL)
        bTerminalID 3
        wTerminalType 0x0101 USB Streaming
        bAssocTerminal 0
        bNrChannels 8
        wChannelConfig 0x063f
          Left Front (L)
          Right Front (R)
          Center Front (C)
          Low Freqency Enhancement (LFE)
          Left Surround (LS)
          Right Surround (RS)
          Side Left (SL)
          Side Right (SR)
        iChannelNames 0
        iTerminal 0
      AudioControl Interface Descriptor:
        bLength 25
        bDescriptorType 36
        bDescriptorSubtype 6 (FEATURE_UNIT)
        bUnitID 4
        bSourceID 3
        bControlSize 2
        bmaControls( 0) 0x01
        bmaControls( 0) 0x00
          Mute Control
        bmaControls( 1) 0x00
        bmaControls( 1) 0x00
        bmaControls( 2) 0x00
        bmaControls( 2) 0x00
        bmaControls( 3) 0x00
        bmaControls( 3) 0x00
        bmaControls( 4) 0x00
        bmaControls( 4) 0x00
        bmaControls( 5) 0x00
        bmaControls( 5) 0x00
        bmaControls( 6) 0x00
        bmaControls( 6) 0x00
        bmaControls( 7) 0x00
        bmaControls( 7) 0x00
        bmaControls( 8) 0x00
        bmaControls( 8) 0x00
        iFeature 0

seem you have selected 5.1 profile in sound preference

seem strange that O05 has no input from left and right ,

do Center or LFE need mix of left and right channels when upmixing from stereo ?

( 24.134| 0.000) I: [alsa-sink] alsa-sink.c: Starting playback.
( 24.134| 0.000) D: [pulseaudio] module-suspe...

[Arkadiusz Piekarz (piekarzarkadiusz)]

Hey Raymond,

> do you mean the log was obtained when you switch to 7.1 since there is no stereo ?
No, it was set to 2.0.

> seem you have selected 5.1 profile in sound preference
Correct, should I change it?

> do Center or LFE need mix of left and right channels when upmixing from stereo ?
Sorry, I have no idea.

[Raymond (superquad-vortex2)]

i don't understand how do 5.1 or 7.1 work in headphone ?

do each headphone has a subwoofer ?

[Raymond (superquad-vortex2)]

can you try the following to find out whether the channel map is cooect

speaker-test -c6 -t wav -d -D surround51: Megalodon

speaker-test -c8 -t wav -d -D surround71: Megalodon

speaker-test -c6 -t wav -d -D hw: Megalodon

speaker-test -c8 -t wav -d -D hw: Megalodon

speaker-test -c2 -t wav -d -D pulse

speaker-test -c6 -t wav -d -D pulse

speaker-test -c8 -t wav -d -D pulse

[Arkadiusz Piekarz (piekarzarkadiusz)]

Hey Raymond, sorry for late reply.

> i don't understand how do 5.1 or 7.1 work in headphone ?
> do each headphone has a subwoofer ?

I took a photo of one piece of the headphones and I think there's only one speaker in there - http://i.imgur.com/OA6ZmWq.jpg
As for the sound, when you enable 7.1 on hardware mode it changes the sound to create a spatial effect - it works, but some of the bandwidth is lost (you don't hear some sounds). Sadly because of that I prefer 2.0 mode.

> can you try the following to find out whether the channel map is cooect

I'll attach the log below (translated to English from Polish). When I tried the commands ending in "Megalodon", there was no sound. It worked correctly with the "pulse" ones.

[Arkadiusz Piekarz (piekarzarkadiusz)]

Good news, after upgrading to Kubuntu 13.10 the problem is completely solved. The headphones work perfectly now.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 13.04 (raring) reached end-of-life on January 27, 2014.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test.

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]