I have a Home Theater Personal Computer. It is connected via HDMI to a Samsung HDTV and then by optical cable to a 5.1 receiver.

Mythtv plays very well, the problem is other computer sounds. These seem to overdrive the the speakers - causing loud spitting unless the volume is very low..

• For instance, when playing audio using Firefox and mog.com when the ALSA plug-in [npviewer.bin] is set low enough to stop the spitting from overdriving in Sound Preferences/Application, the volume is too low to be useful and the volume level of the right speaker is much louder than other speakers. The same thing happens when playing an audio CD and with system sounds.

The Alsa mixer shows only four check boxes for playback and , IEC958, IEC958 1, IEC958 2, and IEC958 3; with the first two checked. Only IEC958 1 affects the audio. For capture, it reports the device does not have any capture devices.

The specs are:

• Ubuntu 10.10 (fully updated)


• Linux 2.6.35-31-generic (x86_64)


• Athlon(tm) X3 445 Processor (3x3.1GHz)


• 4055MB


• Audio Adapter:HDA-Intel-HDA NVidia[nVidia Corporation High Definition Audio Controller/ (rev a1)]


• GeForce GT 240/PCI/SSE2

Mythtv fixes/0.24 (v0.24.1-112-g40f3bae)

The motherboard has built in sound that is disabled in the BIOS.

alsa-info here.

The Loaded snd modules:

snd_hda_codec ⋯ HDA codec core

snd_hda_codec_nvhdmi ⋯ NVIDIA HDMI HD-audio codec

snd_hda_intel ⋯ Intel HDA driver

snd_hwdep ⋯ Hardware dependent layer

snd_page_alloc ⋯ Memory allocator for ALSA system.

snd_pcm ⋯ Midlevel PCM code for ALSA.

snd_rawmidi ⋯ Midlevel RawMidi code for ALSA.

snd_seq ⋯ Advanced Linux Sound Architecture sequencer.

snd_seq_device ⋯ ALSA sequencer device management

snd_seq_midi ⋯ Advanced Linux Sound Architecture sequencer MIDI synth.

snd_seq_midi_event ⋯ MIDI byte <-> sequencer event coder

snd_timer ⋯ ALSA timer interface

From lspci -vvnn for nvidia

01:00.0 VGA compatible controller [0300]: nVidia Corporation GT215 [GeForce GT 240] [10de:0ca3] (rev a2) (prog-if 00 [VGA controller])

    Subsystem: eVga.com. Corp. Device [3842:1242]

    Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-

    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-

    Latency: 0

    Interrupt: pin A routed to IRQ 18

    Region 0: Memory at fc000000 (32-bit, non-prefetchable) [size=16M]

    Region 1: Memory at d0000000 (64-bit, prefetchable) [size=256M]

    Region 3: Memory at ce000000 (64-bit, prefetchable) [size=32M]

    Region 5: I/O ports at d800 [size=128]

    [virtual] Expansion ROM at fde80000 [disabled] [size=512K]

    Capabilities: [60] Power Management version 3

        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)

        Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-

    Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+

        Address: 0000000000000000  Data: 0000

    Capabilities: [78] Express (v2) Endpoint, MSI 00

        DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s unlimited, L1 <64us

            ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-

        DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-

            RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+

            MaxPayload 128 bytes, MaxReadReq 512 bytes

        DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-

        LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Latency L0 <512ns, L1 <4us

            ClockPM+ Surprise- LLActRep- BwNot-

        LnkCtl: ASPM Disabled; RCB 128 bytes Disabled- Retrain- CommClk+

            ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-

        LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-

        DevCap2: Completion Timeout: Not Supported, TimeoutDis+

        DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-

        LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-, Selectable De-emphasis: -6dB

             Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-

             Compliance De-emphasis: -6dB

        LnkSta2: Current De-emphasis Level: -6dB

    Capabilities: [b4] Vendor Specific Information: Len=14 <?>

    Capabilities: [100 v1] Virtual Channel

        Caps:   LPEVC=0 RefClk=100ns PATEntryBits=1

        Arb:    Fixed- WRR32- WRR64- WRR128-

        Ctrl:   ArbSelect=Fixed

        Status: InProgress-

        VC0:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-

            Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-

            Ctrl:   Enable+ ID=0 ArbSelect=Fixed TC/VC=ff

            Status: NegoPending- InProgress-

    Capabilities: [128 v1] Power Budgeting <?>

    Capabilities: [600 v1] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>

    Kernel driver in use: nvidia

    Kernel modules: nvidia-current, nouveau, nvidiafb



01:00.1 Audio device [0403]: nVidia Corporation High Definition Audio Controller [10de:0be4] (rev a1)

    Subsystem: eVga.com. Corp. Device [3842:1242]

    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-

    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-

    Latency: 0, Cache Line Size: 64 bytes

    Interrupt: pin B routed to IRQ 19

    Region 0: Memory at fde7c000 (32-bit, non-prefetchable) [size=16K]

    Capabilities: [60] Power Management version 3

        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)

        Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-

    Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+

        Address: 0000000000000000  Data: 0000

    Capabilities: [78] Express (v2) Endpoint, MSI 00

        DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <4us, L1 <64us

            ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-

        DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-

            RlxdOrd- ExtTag+ PhantFunc- AuxPwr- NoSnoop+

            MaxPayload 128 bytes, MaxReadReq 512 bytes

        DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-

        LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Latency L0 <512ns, L1 <1us

            ClockPM+ Surprise- LLActRep- BwNot-

        LnkCtl: ASPM L0s L1 Enabled; RCB 128 bytes Disabled- Retrain- CommClk+

            ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-

        LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-

        DevCap2: Completion Timeout: Not Supported, TimeoutDis+

        DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-

        LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-, Selectable De-emphasis: -6dB

             Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-

             Compliance De-emphasis: -6dB

        LnkSta2: Current De-emphasis Level: -6dB

    Kernel driver in use: HDA Intel

    Kernel modules: snd-hda-intel