내 USB 오디오 입력 채널 max_out/clips는 약 15%입니다.

내 USB 오디오 입력 채널 max_out/clips는 약 15%입니다.

M-트랙 8 오디오 장치(8 I/O)가 있습니다. 재생이 훌륭합니다. 하지만 마이크(48V XLR 마이크)에서는 소리가 거의 나지 않았습니다. 녹음 시 모든 애플리케이션의 볼륨 제한은 15%로 제한됩니다.

  • 믹서 스펙트럼 분석기에 따르면 매우 잘 작동합니다.
  • m-트랙 입력을 아날로그 출력으로 리디렉션하고 내장 마이크를 사용하여 녹음하면 제대로 작동합니다.
  • macOS나 Windows에서 녹음하면 잘 작동합니다.

따라서 문제는 ALSA 또는 드라이버 어딘가에 있습니다. 이는 일반적인 USB 오디오 클래스 장치이므로 드라이버가 문제가 될 가능성이 없습니다(Gentoo, Ubuntu 20.04 및 Ubuntu 18.04 live-usb에서 재현됨).

  • alsamixer모든 입력을 100%로 표시합니다.
  • pavucontrol모든 입력을 100%로 표시
  • 96kHz를 강제로 적용하기 위해 일부 구성을 추가하려고 시도했지만 .asoundrc아무 효과가 없었습니다.
  • 이 문제는 마이크 증폭과 관련이 없습니다. 매우 약한 신호

믹서-c2:

Simple mixer control 'Mic',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right - Rear Left - Rear Right - Front Center - Woofer - Side Left - Side Right
  Limits: Capture 0 - 127
  Front Left: Capture 127 [100%] [0.00dB] [on]
  Front Right: Capture 127 [100%] [0.00dB] [on]
  Rear Left: Capture 127 [100%] [0.00dB] [on]
  Rear Right: Capture 127 [100%] [0.00dB] [on]
  Front Center: Capture 127 [100%] [0.00dB] [on]
  Woofer: Capture 127 [100%] [0.00dB] [on]
  Side Left: Capture 127 [100%] [0.00dB] [on]
  Side Right: Capture 127 [100%] [0.00dB] [on]
Simple mixer control 'Mic',1
  Capabilities: cvolume cvolume-joined cswitch cswitch-joined
  Capture channels: Mono
  Limits: Capture 0 - 127
  Mono: Capture 127 [100%] [0.00dB] [on]
Simple mixer control 'M-Audio M-Track Eight',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right - Rear Left - Rear Right - Front Center - Woofer - Side Left - Side Right
  Limits: Playback 0 - 127
  Mono:
  Front Left: Playback 121 [95%] [-6.00dB] [on]
  Front Right: Playback 121 [95%] [-6.00dB] [on]
  Rear Left: Playback 127 [100%] [0.00dB] [on]
  Rear Right: Playback 127 [100%] [0.00dB] [on]
  Front Center: Playback 127 [100%] [0.00dB] [on]
  Woofer: Playback 127 [100%] [0.00dB] [on]
  Side Left: Playback 127 [100%] [0.00dB] [on]
  Side Right: Playback 127 [100%] [0.00dB] [on]
Simple mixer control 'M-Audio M-Track Eight',1
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 127
  Mono: Playback 127 [100%] [0.00dB] [on]

lsusb -vv -d 0763:4003

Bus 001 Device 049: ID 0763:4003 M-Audio 
Couldn't open device, some information will be missing
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x0763 M-Audio
  idProduct          0x4003 
  bcdDevice            1.05
  iManufacturer           1 
  iProduct                3 
  iSerial                 0 
  bNumConfigurations      2
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0148
    bNumInterfaces          4
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         0
      bInterfaceCount         3
      bFunctionClass          1 Audio
      bFunctionSubClass       0 
      bFunctionProtocol      32 
      iFunction               0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      1 Control Device
      bInterfaceProtocol     32 
      iInterface              3 
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               2.00
        bCategory               8
        wTotalLength       0x00a7
        bmControls           0x00
      AudioControl Interface Descriptor:
        bLength                 8
        bDescriptorType        36
        bDescriptorSubtype     10 (CLOCK_SOURCE)
        bClockID               41
        bmAttributes            3 Internal programmable clock 
        bmControls           0x07
          Clock Frequency Control (read/write)
          Clock Validity Control (read-only)
        bAssocTerminal          0
        iClockSource            9 
      AudioControl Interface Descriptor:
        bLength                 8
        bDescriptorType        36
        bDescriptorSubtype     11 (CLOCK_SELECTOR)
        bClockID               40
        bNrInPins               1
        baCSourceID(0)         41
        bmControls           0x03
          Clock Selector Control (read/write)
        iClockSelector          8 
      AudioControl Interface Descriptor:
        bLength                17
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             2
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bCSourceID             40
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
        bmControls         0x0000
        iTerminal               6 
      AudioControl Interface Descriptor:
        bLength                42
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                10
        bSourceID               2
        bmaControls(0)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(1)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(2)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(3)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(4)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(5)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(6)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(7)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(8)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        iFeature                0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID            20
        wTerminalType      0x0301 Speaker
        bAssocTerminal          0
        bSourceID              10
        bCSourceID             40
        bmControls         0x0000
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                17
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             1
        wTerminalType      0x0201 Microphone
        bAssocTerminal          0
        bCSourceID             40
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
        bmControls         0x0000
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                42
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                11
        bSourceID               1
        bmaControls(0)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(1)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(2)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(3)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(4)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(5)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(6)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(7)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(8)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        iFeature                0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID            22
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bSourceID              11
        bCSourceID             40
        bmControls         0x0000
        iTerminal               7 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              4 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              4 
      AudioStreaming Interface Descriptor:
        bLength                16
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           2
        bmControls           0x00
        bFormatType             1
        bmFormats          0x00000001
          PCM
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          11 
      AudioStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bSubslotSize            4
        bBitResolution         24
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               1
        AudioStreaming Endpoint Descriptor:
          bLength                 8
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bmControls           0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0008
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes           17
          Transfer Type            Isochronous
          Synch Type               None
          Usage Type               Feedback
        wMaxPacketSize     0x0004  1x 4 bytes
        bInterval               4
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              5 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              5 
      AudioStreaming Interface Descriptor:
        bLength                16
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink          22
        bmControls           0x00
        bFormatType             1
        bmFormats          0x00000001
          PCM
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
      AudioStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bSubslotSize            4
        bBitResolution         24
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               1
        AudioStreaming Endpoint Descriptor:
          bLength                 8
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bmControls           0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0008
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass       254 Application Specific Interface
      bInterfaceSubClass      1 Device Firmware Update
      bInterfaceProtocol      1 
      iInterface             10 
      Device Firmware Upgrade Interface Descriptor:
        bLength                             9
        bDescriptorType                    33
        bmAttributes                        7
          Will Not Detach
          Manifestation Tolerant
          Upload Supported
          Download Supported
        wDetachTimeout                    250 milliseconds
        wTransferSize                      64 bytes
        bcdDFUVersion                   1.10
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0148
    bNumInterfaces          4
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         0
      bInterfaceCount         3
      bFunctionClass          1 Audio
      bFunctionSubClass       0 
      bFunctionProtocol      32 
      iFunction               0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      1 Control Device
      bInterfaceProtocol     32 
      iInterface              3 
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               2.00
        bCategory               8
        wTotalLength       0x00a7
        bmControls           0x00
      AudioControl Interface Descriptor:
        bLength                 8
        bDescriptorType        36
        bDescriptorSubtype     10 (CLOCK_SOURCE)
        bClockID               41
        bmAttributes            3 Internal programmable clock 
        bmControls           0x07
          Clock Frequency Control (read/write)
          Clock Validity Control (read-only)
        bAssocTerminal          0
        iClockSource            9 
      AudioControl Interface Descriptor:
        bLength                 8
        bDescriptorType        36
        bDescriptorSubtype     11 (CLOCK_SELECTOR)
        bClockID               40
        bNrInPins               1
        baCSourceID(0)         41
        bmControls           0x03
          Clock Selector Control (read/write)
        iClockSelector          8 
      AudioControl Interface Descriptor:
        bLength                17
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             2
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bCSourceID             40
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
        bmControls         0x0000
        iTerminal               6 
      AudioControl Interface Descriptor:
        bLength                42
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                10
        bSourceID               2
        bmaControls(0)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(1)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(2)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(3)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(4)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(5)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(6)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(7)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(8)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        iFeature                0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID            20
        wTerminalType      0x0301 Speaker
        bAssocTerminal          0
        bSourceID              10
        bCSourceID             40
        bmControls         0x0000
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                17
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             1
        wTerminalType      0x0201 Microphone
        bAssocTerminal          0
        bCSourceID             40
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
        bmControls         0x0000
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                42
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                11
        bSourceID               1
        bmaControls(0)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(1)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(2)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(3)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(4)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(5)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(6)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(7)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        bmaControls(8)     0x0000000f
          Mute Control (read/write)
          Volume Control (read/write)
        iFeature                0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID            22
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bSourceID              11
        bCSourceID             40
        bmControls         0x0000
        iTerminal               7 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              4 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              4 
      AudioStreaming Interface Descriptor:
        bLength                16
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           2
        bmControls           0x00
        bFormatType             1
        bmFormats          0x00000001
          PCM
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          11 
      AudioStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bSubslotSize            4
        bBitResolution         24
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               1
        AudioStreaming Endpoint Descriptor:
          bLength                 8
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bmControls           0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0008
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes           17
          Transfer Type            Isochronous
          Synch Type               None
          Usage Type               Feedback
        wMaxPacketSize     0x0004  1x 4 bytes
        bInterval               4
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              5 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol     32 
      iInterface              5 
      AudioStreaming Interface Descriptor:
        bLength                16
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink          22
        bmControls           0x00
        bFormatType             1
        bmFormats          0x00000001
          PCM
        bNrChannels             8
        bmChannelConfig    0x00000000
        iChannelNames          19 
      AudioStreaming Interface Descriptor:
        bLength                 6
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bSubslotSize            4
        bBitResolution         24
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0400  1x 1024 bytes
        bInterval               1
        AudioStreaming Endpoint Descriptor:
          bLength                 8
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bmControls           0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0008
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass       254 Application Specific Interface
      bInterfaceSubClass      1 Device Firmware Update
      bInterfaceProtocol      1 
      iInterface             10 
      Device Firmware Upgrade Interface Descriptor:
        bLength                             9
        bDescriptorType                    33
        bmAttributes                        7
          Will Not Detach
          Manifestation Tolerant
          Upload Supported
          Download Supported
        wDetachTimeout                    250 milliseconds
        wTransferSize                      64 bytes
        bcdDFUVersion                   1.10

pacmd list-sources inputs:

   index: 16
        name: <alsa_output.usb-M-Audio_M-Track_Eight-00.analog-surround-71.monitor>
        driver: <module-alsa-card.c>
        flags: DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
        state: RUNNING
        suspend cause: (none)
        priority: 1040
        volume: front-left: 65536 / 100% / 0.00 dB,   front-right: 65536 / 100% / 0.00 dB,   rear-left: 65536 / 100% / 0.00 dB,   rear-right: 65536 / 100% / 0.00 dB,   front-center: 65536 / 100% / 0.00 dB,   lfe: 65536 / 100% / 0.00 dB,   side-left: 65536 / 100% / 0.00 dB,   side-right: 65536 / 100% / 0.00 dB
                balance 0.00
        base volume: 65536 / 100% / 0.00 dB
        volume steps: 65537
        muted: no
        current latency: 0.00 ms
        max rewind: 11 KiB
        sample spec: s32le 8ch 44100Hz
        channel map: front-left,front-right,rear-left,rear-right,front-center,lfe,side-left,side-right
                     Surround 7.1
        used by: 5
        linked by: 5
        configured latency: 40.00 ms; range is 8.00 .. 743.04 ms
        monitor_of: 7
        card: 5 <alsa_card.usb-M-Audio_M-Track_Eight-00>
        module: 27
        properties:
                device.description = "Monitor of M-Track Eight Analog Surround 7.1"
                device.class = "monitor"
                alsa.card = "2"
                alsa.card_name = "M-Track Eight"
                alsa.long_card_name = "M-Audio M-Track Eight at usb-0000:00:14.0-5.4, high speed"
                alsa.driver_name = "snd_usb_audio"
                device.bus_path = "pci-0000:00:14.0-usb-0:5.4:1.0"
                sysfs.path = "/devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5.4/1-5.4:1.0/sound/card2"
                udev.id = "usb-M-Audio_M-Track_Eight-00"
                device.bus = "usb"
                device.vendor.id = "0763"
                device.vendor.name = "M-Audio"
                device.product.id = "4003"
                device.product.name = "M-Track Eight"
                device.serial = "M-Audio_M-Track_Eight"
                device.string = "2"
                module-udev-detect.discovered = "1"
                device.icon_name = "audio-card-usb"

이것은 녹음입니다:

parecord -r --format=s24le --file-format=wav ./foo.wav

file ./foo.wav
./foo.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 24 bit, stereo 44100 Hz

소리는 마이크에서 나오며 장치에 잘립니다(Vu 미터를 표시하는 빨간색 막대).

여기에 이미지 설명을 입력하세요.

여기에 이미지 설명을 입력하세요.

답변1

나는 명백한 것을 보지 못하지만 두 가지 생각을 가지고 있습니다.

  1. USB 장치에는 두 가지 구성이 있지만 표시된 정보에 따르면 동일한 것으로 보입니다. 그래서 나는 그것들이 무엇을 위한 것인지 모릅니다. 다른 것으로 전환해 보고( usb_modeswitch먼저 커널 모듈 제거) 변경 사항이 있는지 확인할 수 있습니다.

  2. 설명자를 올바르게 읽으면 4바이트에 24비트가 전송됩니다. 일반 USB 오디오 드라이버가 잘못된 3바이트를 선택하면 최상위 바이트가 0이 되어 레벨이 12.5%로 제한됩니다(관찰한 15%와 일치).

    parecord예를 들어 일부 파일(WAV 또는 원시)에 24비트 형식으로 녹음하고 16진수 편집기로 확인하여 이를 확인할 수 있습니다 . 모든 샘플의 MSB가 0인 경우 생성한 볼륨이 Mac 또는 Windows에서 잘린 경우에도 마찬가지일 수 있습니다.

    또한 USB 패킷을 캡처하는 데 사용할 수 있으므로 wireshark기록된 데이터에 포함되지 않은 샘플에 추가 세 번째 바이트가 있는지 비교할 수 있습니다.

이런 경우는 드라이버의 버그이므로 ALSA 커널 목록에 버그 리포트를 제출해 주시기 바랍니다.


사용 사례 간략히 살펴보기: 일반적으로 사람들은 각 멤버가 하나 또는 두 개의 마이크(보컬 + 악기)를 사용하는 밴드와 같이 여러 개의 마이크를 사용하여 녹음하기 위해 M-track 8과 같은 제품을 구입합니다. 이 경우 Pulseaudio에서 8개 채널을 모두 가져오면(다운믹싱 비활성화) DAW가 실제로 녹음한 채널을 선택합니다.

대기 시간만 추가하고 ALSA로 직접 이동하거나 Pulseaudio 대신 Jack을 사용하므로 이를 위해 Pulseaudio를 완전히 비활성화하는 경우도 많습니다.

"저는 제 노트북이 7.1 서라운드 스피커나 스테레오 헤드폰으로 재생될 수 있기를 원합니다. 그리고 전화 회의 중이라면 사람들이 제 말을 들을 수 있기를 바랍니다.

좋습니다. 마이크가 하나만 있으면 됩니다. 사용 사례에서는 그게 전부입니다. 또한 대기 시간 문제가 없고 주로 출력에 8채널을 사용하므로 Pulseaudio를 유지하려고 합니다.

그러니 한번 보세요모듈 재매핑 소스그리고 다음과 같은 일을 하세요

load-module module-remap-source master=alsa_input.usb-MTRACK.analog-stereo channels=1 master_channel_map=front-left channel_map=mono

front-left마이크가 켜져 있는 채널은 M MTRACK-Track 소스의 실제 이름으로 대체됩니다(예: 사용 pactl list short). 그런 다음 새 소스에서 녹음합니다.

유일한 실제 문제가 Pulseaudio가 8개 채널을 모두 스테레오로 다운믹스하고 레벨을 줄이는 것이라면 이제 괜찮을 것입니다.

다른 문제가 있는 경우 설명에 설명된 대로 Pulseaudio 없이 ALSA만 사용하여 8개 채널을 모두 테스트하여 Pulseaudio를 배제하고 문제가 ALSA 드라이버에 있는지 확인할 수 있습니다.

관련 정보