DOSBox-X provides comprehensive DOS audio emulation through several independently configurable subsystems. TheDocumentation Index
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[mixer] section sets the global audio pipeline parameters. The [midi] section handles General MIDI and Roland MT-32 output. The [sblaster] section emulates Creative Sound Blaster cards (the most common DOS audio standard), while [gus] handles the Gravis UltraSound. The [speaker] section covers the PC speaker, Tandy 3-Voice, and Disney Sound Source. The [innova] section emulates the Innovation SSI-2001 SID-chip card, and [imfc] provides IBM Music Feature Card support. Most changes require a restart of DOSBox-X to take effect.
Mixer — [mixer]
Enable silent mode. When set, all audio hardware is still emulated (so programs do not crash), but no sound is actually output to the host audio system. Useful for recording sessions or automated testing.
Global mixer sample rate in Hz. All emulated audio devices are mixed and output at this rate. Setting any device’s individual rate higher than this value will likely degrade that device’s audio quality. Common values:
8000, 11025, 16000, 22050, 32000, 44100, 48000.Audio block size in samples. Larger blocks reduce the chance of audio stuttering by providing more buffer headroom, but increase audio latency. Possible values:
256, 512, 1024, 2048, 4096, 8192.Amount of audio data (in milliseconds) to keep pre-buffered on top of the block size. Increasing this value provides more headroom against buffer underruns at the cost of additional latency.
When enabled, applies a slow DC bias correction to the master audio mix. This prevents audio distortion in DOS games whose digitized audio samples have a significant DC offset away from zero (for example, In Extremis). The correction is applied gradually so that normal audio is unaffected.
Enable sample-accurate audio mixing. This improves timing accuracy for Tandy 3-Voice, OPL, and Gravis UltraSound output — notably for DOS demoscene productions that require it — at the cost of slightly higher CPU usage.
Swap the left and right stereo audio channels globally. Useful if your speakers or headphones are connected in reverse.
MIDI — [midi]
Type of MPU-401 MIDI interface to emulate. Possible values:
intelligent— full MPU-401 intelligent mode (recommended for most games)uart— simpler UART mode onlynone— disable MPU-401 emulation
I/O base address of the MPU-401 interface. Set to
0 to use the default address (330h for IBM PC mode, E0D0h for PC-98 mode). Other valid values for IBM PC: 300, 310, 320, 330, 332, 334, 336, 340, 360. Values in the c0d0–f8d0 range are for PC-98 MPU98 mode.IRQ used by the MPU-401. Set to
-1 to let DOSBox-X assign an IRQ automatically.Device that receives MIDI data from the MPU-401. Possible values:
default— use the system default MIDI outputwin32— Windows MIDI mapperalsa— ALSA sequencer (Linux)oss— OSS MIDI (Linux)coreaudio— macOS Core Audio synthesizer (can load a soundfont viamidiconfig)coremidi— macOS Core MIDI output portmt32— Roland MT-32 emulation (requires ROMs inmt32.romdir)synth— built-in synthesis (soundfont viamidiconfig)fluidsynth— FluidSynth software synthesizertimidity— TiMidity++ software synthesizernone— discard all MIDI output
Device-specific configuration for the selected MIDI device, typically the device ID or part of its name (find available devices with the
listmidi mixer command). For coreaudio or synth, specify a soundfont path here. For hardware MT-32 devices with buffer overflow issues, append delaysysex (e.g. midiconfig=2 delaysysex).Sample rate for software MIDI synthesizers. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.MT-32 Emulation
Directory containing the MT-32 or CM-32L ROM files required for MT-32 emulation. Accepted filenames:
MT32_CONTROL.ROMorCM32L_CONTROL.ROM— control ROMMT32_PCM.ROMorCM32L_PCM.ROM— PCM ROM
MT-32 model variant to emulate. Possible values:
auto— automatically select based on available ROM filesmt32— emulate the original Roland MT-32cm32l— emulate the Roland CM-32L (enhanced model)
FluidSynth
Audio driver for FluidSynth to use. Not needed on Windows. Available drivers depend on FluidSynth’s compile-time configuration. Possible values:
pulseaudio, alsa, oss, coreaudio, dsound, portaudio, sndman, jack, file, default.Path to the SF2 or SF3 soundfont file used by FluidSynth for MIDI synthesis. A soundfont must be specified when
mididevice=fluidsynth. Example: fluid.soundfont=GeneralUser_GS.sf2.Sound Blaster — [sblaster]
Type of Creative Sound Blaster card to emulate. Possible values:
sb1/sb1.0/sb1.5— Sound Blaster 1.xsb2/sb2.0/sb2.01— Sound Blaster 2.xsbpro1— Sound Blaster Pro (first generation)sbpro2— Sound Blaster Pro 2sb16— Sound Blaster 16 (default, most compatible)sb16vibra— Sound Blaster 16 with ViBRA chipsetgb— Game Blaster (CMS / Creative Music System)ess688/ess1688— ESS Technology compatible cardsreveal_sc400— Reveal SC-400 compatible cardnone— disable Sound Blaster emulation
I/O base address of the Sound Blaster card. For IBM PC mode:
220, 240, 260, 280, 2a0, 2c0, 2e0. For NEC PC-98 Sound Blaster 16 mode: d2, d4, d6, d8, da, dc, de. The most common DOS setting is 220 (0x220).IRQ used by the Sound Blaster. Common values are
5 and 7 depending on card type. Set to 0 for the card default, or -1 to start with IRQ unassigned. Possible values: -1, 0, 3, 5, 7, 9, 10, 11, 12.When the guest records audio from the Sound Blaster card, also send the input source to the speakers so it can be heard in real time.
Audio source used when the guest is recording. Possible values:
silence, hiss, 1khz tone, microphone (Windows WASAPI microphone input).When enabled, prefer a Bluetooth HFP (Hands-Free Profile) microphone if available. This allows using a BT headset microphone but reduces audio quality to telephone grade (typically 8–16 kHz). When disabled, higher-quality microphones are preferred.
DMA channel for 8-bit Sound Blaster audio transfers. Set to
-1 to start with DMA unassigned. Possible values: -1, 0, 1, 3, 5, 6, 7.High (16-bit) DMA channel for Sound Blaster 16 transfers. Set to
-1 to start unassigned. Possible values: -1, 0, 1, 3, 5, 6, 7.Start with the Sound Blaster output speaker already enabled. Sound Blaster Pro and older cards boot with the speaker disabled by default; some early DOS games do not issue the speaker-enable command and will produce no sound unless this is set to
true. Has no effect for Sound Blaster 16 emulation.Allow the Sound Blaster’s on-card mixer to affect the DOSBox-X master mixer levels. Disable if a program incorrectly mutes or distorts the DOSBox-X audio mix.
OPL FM synthesis mode. With
auto, the mode is determined by the sbtype setting. All OPL modes are AdLib-compatible. Possible values:auto— determined automaticallyopl2— OPL2 (AdLib, SB1/SB2)dualopl2— dual OPL2 (SB Pro stereo)opl3— OPL3 (SB16, AWE32)opl3gold— OPL3 Goldesfm— ESS FMnone— disable OPLhardware— pass through to real OPL hardwarehardwaregb— pass through for Game Blaster hardware
OPL emulation backend. Possible values:
default— DOSBox-X default emulatorcompat— compatibility-focused emulator (often better quality)fast— fast but less accuratenuked— most accurate emulation, highest CPU costmame— MAME OPL emulatoropl2board— real OPL2 Audio Board hardware (setoplport)opl3duoboard— OPL3 Duo! Board hardwareretrowave_opl3— Retrowave OPL3 board hardwareesfmu— ESS FM emulation
Sample rate for OPL FM synthesis output. Use
49716 for the highest quality. Possible values: 8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.Serial port used when
oplemu=opl2board. Specifying this enables passthrough to a real OPL2 Audio Board connected via serial. Leave empty unless you have real OPL hardware.Bus type for Retrowave series OPL boards. Possible values:
serial, spi (SPI is only supported on Linux).Serial port used to communicate with a Retrowave OPL3 board. Required when
oplemu=retrowave_opl3.Base I/O address of a real Sound Blaster card when using hardware passthrough (
oplemu=hardware). Valid values: 210, 220, 230, 240, 250, 260, 280.Enable Goldplay emulation. Goldplay is a technique some DOS games use to play digitized audio through the PC speaker or Sound Blaster by rapidly toggling the speaker gate.
Automatically set the
BLASTER DOS environment variable at startup with the current SB configuration. Most DOS games read this variable to determine the Sound Blaster address, IRQ, and DMA channels.Gravis UltraSound — [gus]
Enable Gravis UltraSound (GUS) emulation. When enabled, a GUS card is presented to the DOS guest at the configured I/O base, IRQ, and DMA settings.
Sample rate for GUS audio output. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.Amount of RAM installed on the emulated GUS card, in kilobytes. Set to
-1 to use the default for the selected gustype.Master GUS GF1 volume in decibels. Reducing this (e.g. to
-6.00) can help prevent clipping on DOS games and demos with loud music.I/O base address of the GUS card. Possible values:
210, 220, 230, 240, 250, 260, 280, 2a0, 2c0, 2e0, 300.IRQ used by the GUS. Possible values:
3, 5, 7, 9, 10, 11, 12.DMA channel used by the GUS. Possible values:
0, 1, 3, 5, 6, 7.Type of Gravis UltraSound to emulate. Possible values:
classic— original GUS chipsetclassic37— original GUS with ICS Mixer (revision 3.7)max— GUS MAX (with CS4231 codec)interwave— GUS Plug and Play (InterWave chipset)
Path to the Gravis UltraSound software directory. This directory should contain a
MIDI subdirectory with GUS patch files. Timidity-compatible patch sets work with GUS emulation.PC Speaker & Other — [speaker]
Enable PC speaker emulation. The PC speaker is a single-channel square-wave generator built into the system board, used by many early DOS games and system sounds.
Sample rate for PC speaker sound synthesis. Higher values improve audio quality. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716, 65536.Enable Tandy 3-Voice sound emulation. Possible values:
auto— emulate only whenmachine=tandyon— always emulate Tandy soundoff— disable Tandy sound
Sample rate for Tandy 3-Voice audio synthesis. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.Enable Disney Sound Source emulation (also compatible with Covox Voice Master and Speech Thing devices). This is a simple parallel-port DAC used by some early DOS games for digitized speech and music.
Enable IBM PS/1 audio emulation. Possible values:
on, off.Sample rate for PS/1 audio emulation. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.Innovation SSI-2001 — [innova]
Enable Innovation SSI-2001 emulation. The SSI-2001 is a SID-chip based sound card used in a small number of DOS games.
Sample rate for SSI-2001 SID chip emulation. Possible values:
8000, 11025, 16000, 22050, 32000, 44100, 48000, 49716.I/O base port for the SSI-2001 card (typically 280h). Possible values:
220, 240, 260, 280, 2a0, 2c0, 2e0, 300.SID emulation quality level. Higher values produce better audio at greater CPU cost. Possible values:
0, 1, 2, 3.