3 min read

Some thoughts on virtual surround sound

There’re software solutions and hardware solutions. Software solutions run on general operating systems like macOS, Windows, iOS, Linux, and Androids, while hardware solutions run in DACs like Creative’s Sound BlasterX G6, Sennheiser GSX 1000, or headphones like Audeze Morbius...
Some thoughts on virtual surround sound
  1. There’re software solutions and hardware solutions. Software solutions run on general operating systems like macOS, Windows, iOS, Linux, and Androids, while hardware solutions run in DACs like Creative’s Sound BlasterX G6, Sennheiser GSX 1000, or headphones like Audeze Morbius. However, it’s not always easy to distinguish the two. More often than not a DAC is using its proprietary software to virtualize surround or stereo sound, like the SBX implementation found in Sound Blaster X4.
  2. There’s spatial sound framework in Windows 10 and 11. Windows Sonic, Dolby Atmos for Headphones, and DTS Headphone:X all utilizes this framework. It is kind of system-wide, and kind of not, because it needs source apps to specify it as sound output destination. It’s a hit or miss experience. System sound won’t go through it, neither do YouTube videos, but Netflix will. Potplayer needs some tweaking, and Foobar2000 does it out of the box. Many games supports it but not all.
  3. For a true system-wide VSS solution on Windows, you can try HeSuVi out. I used to route 7.1ch surround sound into DAS like Reaper to activate Dolby Atmos for Headphones, too.
  4. Sound BlasterX G6 is great, until I found that it won’t receive surround sound on macOS. If you don’t own a Mac, it can virtualize 7.1 on Windows, or 5.1 on anything that outputs Dolby Digital (AC3) bitstream through S/PDIF.
  5. Apple Silicon Macs do not send bitstream output system-wide. That is, if you connect a Mac to a TV through HDMI, and then hook a G6 to the TV through S/PDIF, you can only select 2ch output in MIDI setup under macOS. There will be “encoded digital sound” options or so but it’s greyed out. However, it’s possible to passthrough DD bitstream through HDMI to the TV and G6. You just need to use specific apps, like the TV app or VLC. Also the audio codec needs to be AC3, not AAC, not TrueHD, not even EAC3 (Dolby Digital Plus). Silly I know.
  6. At this point I believe Apple has already abandoned not just S/PDIF but the whole bitstream idea. Maybe it’s licensing, I’m not sure. Messing with S/PDIF on macOS is like trying to play a DVD movie on macOS — you can do it, but it feels obsolete. I can imagine Tim Apple saying “Just buy a new AV receiver and use HDMI instead, It just works!” And it’s true. HDMI can do LPCM 8ch while S/PDIF can only do PCM 2ch and DD 5.1ch.
  7. Yes so there’re two ways of transmitting 7.1ch surround sound right now: HDMI and USB. HDMI is more universal and if you’re building a real surround sound system, it is the way to go. Almost any sound source — smart TVs, computers, consoles — supports it, so do AV receivers. But if you want to build a virtual surround system, good luck with it.
  8. Almost all hardware VSS solutions use USB for 7.1ch surround sound. They’ll support Windows 100%, but Linux and macOS are not always supported. PS4/5 and Xbox are not supported.
  9. Smyth Research Realiser A16 is an exception (Edit: No it’s not. See 11.). It can take HDMI input, but it also costs US$4,195. Yamaha AVRs also have their own virtualizer called Silent Cinema, but I’m unsure of its effect.
  10. I bought a Sound Blaster GC7 and I’ll test it once it arrives. I’m curious of how SXFi sounds, but I also want SBX, so GC7 it is. It can do 7.1ch LPCM from PC/Mac through USB and 5.1ch DD through S/PDIF so it’s very universal. Aside from no HDMI input, it’s also a bit too big compared to G6. I might carry it around so it’s a concern for me.
  11. Apparently Creative also has a soundbar called SXFi Carrier that supports HDMI 2.1 input, including LPCM 8ch and Dolby Atmos (TrueHD!), and of course DD and DD+. It’s also US$999. Not cheap, but it seems like a “budget” buy compared to A16.