SOFA virtual surround is amazing and you should try it!!
I was asked a question in another issue and I felt like this deserved a post of its own. If anyone's on reddit or whatever, please feel free to re-post this. I want to spread the word. The people who did this deserve recognition.
May I ask have you compared sofa filter vs atmos, or any hesuvi file
This is a long post because the short version is that SOFA is absolutely amazing and I want to encourage people as much as I possibly can, to try it, so they can enjoy it like I am, and so they can appreciate the people who gave it to us like I do.
Perspective...
Before I answer this I'm gonna say, I'm a bit of an audiophile snob and strongly opinionated about audio quality. It's not a status or fashion thing or anything, just a consequence of circumstance. Like, I'm a fish snob, because as a kid, I grew up around sailors, so when I ate a fish, we caught it, and we took this live fish and beheaded and gutted and scaled it right there on the gunwales, and took it into the galley and cooked it and then we ate it while we fished for more fish. Every fish I ate was alive 10 minutes ago. So I got used to fresh fish and became a fish snob. It was the same for me with music.
I started out playing musical instruments at a very young age (3 - mostly classical and jazz and blues guitar, and a little drumming) and was really into physics and electronics, and it all blended together and grew into a strong case of audiophilia.
Later on I used to run a small recording studio, as well as a substantial home studio worth more than the house it was in, I've done professional PA setups for large concerts (and conferences), high-end car audio systems professionally (a side gig but getting paid nonetheless).... Before you could buy headphone amps, I built my own based on the schematics for the amp from one of my mixing desks, it was as big as a cassette Walkman and had a battery life of just over an hour or so because this was long before lithium or rechargeable batteries, and I used it to drive full-size over-ear studio monitor headphones on the move, and people used to stare at me because back then, people didn't do that (although it's normal now, wearing beats by dre would make you a freak back then) my portable DAP was the size of a small backpack, literally, I carried a backpack so I could play music on the move.
When I set up home hifi systems for myself or friends (they always ask me to do it) I take room responses and measure speaker distances to calibrate the speakers and tune everything perfectly, I generally use 5.1 (because practically nothing is a 7.1 or more source yet) but I don't ever use a single subwoofer, because I don't subscribe to the notion that low frequency audio is omnidirectional (fight me, Dolby!
I always tell all my friends to keep their speakers off the walls and off of cabinets and tabletops and away from corners and fill empty wall space because it all sounds cruddy, all my headphones are customised with special pads and tips and cables and all manner of stuff - although I don't go in for the stupid money grabbers like gold plated digital connectors (lol), or balanced cables for 1m long cable runs, that do nothing for quality at all, I do braid and solder and sheath my own cables to get the lengths correct for my body and the device, to avoid cable microphonics, and avoid ear fatigue...
....I'm an audio snob. So take my opinions from that perspective. You may think of this as over-cooked snobbery from some idiot who takes it way too seriously, or maybe you'll think this adds more weight to what I'm saying, maybe a little of both... that's up to you (and I take no offense either way), but I feel like understanding my perspective is important here, because I'll be rather blunt about it (although I removed expletives hehehe)
Observations:
Contenders:
Yep. I tried both atmos and hesuvi some time ago, a few times each over time, HeSuVi moreso, most recently a couple of years ago, when I was on Windows, and thought it was completely average at best, like all the other virtual surround solutions I'd ever heard. I was staunchly anti-virtual-surround, always had been, and try as I might - and I did try, because I believe in the theory that good quality virtual surround is 100% possible, I'd never heard anything that changed my mind. Even most true surround systems didn't do much for me, I mostly preferred good quality stereo (as in, two channel audio, but I didn't mind multiple speaker approaches to 2 channel, like quadraphonic speakers playing stereophonic signals) . I mentioned how I set up my surround systems but a great deal of the time they are only playing stereo, just three or four speakers per side.
The only superior solution I'd heard for virtual surround is in the battlefield game series starting from BF4 and the same tech in early BF1 (they broke it a little in later patches of BF1 and BFV was just ordinary), when they had Dolby engineers come on board at EA and they do a 360x360 degree practically infinite resolution sphere (pretty sure it's degrees measured in 32bit floating point, so... a lot of fractions of a degree (actually the math is easy 360/0xFFFFFFFF*2= 0.00000016763806346982 degree resolution)) of audio, and position every sound in the game according to the location of the model in the game, so it's like infinite speakers. That really blew me away, you could stand next to a static audio source like a fire in a barrel, and turn your in-game character around in circles and look up and down and hear very clearly exactly where the sound was., and walk around with your eyes closed and tell how far you'd walked... it sounded real AF. They did a great job. There are a few similar implementations in games these days, because they can use the position of the in-game object as the source of the audio and it's all very precisely defined, so it was all about their algorithm for positioning, and naturally, Dolby are gonna kick some butt with that kind of thing. BF4 was ground-breaking. Not only in positioning but in occlusion and reflection (like the echoes of footsteps on hard floors indoors, or the sound of footsteps through a wooden wall vs through glass, etc)
SOFA:
But otherwise, I'd never heard virtual surround worth a damn. HeSuVi really improved a lot over the years (it's been around a LONG time now!) and to their credit, they've really got that going pretty well. No doubt, that takes second place. But it became a distant second when I read about the SOFA filter in pipewire, and thought, meh, I'll give it a try.... I'm always open to possibilities.... and I was b l o w n a w a y . Mind you, I spend an entire month finding the most correct model of my ears that I could out of the tens (hundreds?) of thousands of models freely available online - and the model makes a BIG difference (and I intend to make use of a tool that will take a 3D scan of your ear and make a model from that, when I have the time to get the equipment to take the scan) and two full days getting the speaker positions just right (which turned out to be nowhere near where I expected). But the results are just astounding. I was so amazed, I was like "holy cow, people need to hear this" but it's kinda like VRR monitors, or high refresh rate.... you can't demonstrate it without actually looking at the real thing, and you can't explain this without actually hearing it.... so I played it to a tech savvy friend to be like "how amazing is this", intending to show off the technology, and played helicopter sounds flying around him... and he's a war vet and I gave him a PTSD attack I kid you not. I'm not proud of that, it was a stupid accident and an absent-minded foolish choice for a demo sound, I'm a total frickin' idiot and I regret it terribly.... but it's a strong illustration of how real it sounds. He lasted about 3 or 4 seconds before he literally threw the headphones off his head and said, and I quote, "if this S### gets any better people are gonna end up killing themselves in movie theatres". And they were tuned for my ears, not his, so he wasn't even getting the full experience. With his hearing loss from artillery, not even close to the full experience. And his reaction was that strong.
Now I use it everywhere. My entire audio chain is surround, now. When I started using pipewire I was locked to stereo everywhere, unless it was a surround source playing to a surround speaker rig. If there was stereo anywhere in the chain, it was all mixed down to stereo at the source and treated as stereo throughout the entire chain. There are even posts on this issues log where you can see me talking about troubles I had locking it down that way. Now I upmix everything (a simple copy, no processing/filtering/delays/etc) because SOFA spreads it so perfectly that it doesn't distort the quality of the audio, which is a big deal to me as a musician and music lover. Usually virtual surround of upmixed music sounds like trash, the frequency response is all messed up and you lose a bunch of sound and it boosts certain other sounds... Hi-hats are super prone to distortion, guitars lose their tone, orchestras lose their depth and dynamics (that's one of the strongest ill-effects I find).... SOFA doesn't do any of that. You just feel like you're literally sitting in the middle of the band or orchestra sitting in a circle around you facing inward, like a reversed concert stage. I have a 5.1 recording of a concert I attended and it literally sounds like being there, it's amazing.
The only thing it's missing is a good tool to mix it with head tracking - and such tools DO exist, but they're a bit hard to set up, so I haven't done that yet, but I'm going to do it. Because the positioning is so strong that you feel like you can't move your head at all, or the whole 'world' in audio moves with your head and it's just bizarre to the brain.
But it's just amazing, there's a mind-blowing number of models available - which is a blessing and a curse, because you DO need to find the right model for your ears/head, to truly benefit from it, and it's like finding a needle in a haystack.... but pipewire's implementation makes it so easy to get it just right. Once you find the model, you just have to get the speaker positions just so, and it's literally just punch in the angles, really simple stuff.
I really want to encourage people to put in the effort - and it is a fairly considerable effort to be honest - to try it out, so they can experience it, and so they can appreciate thee amazing work that all the people involved have done - from uni nerds doing doctoral theses and publishing their models, to programmer nerds at pipewire making it a thing we can all experience, these people have done something amazing and I want everyone to know about it and to feel the enjoyment of it and to feel the appreciation for these people. I feel like nobody is talking about it and it's as if I'm the only person in the world who has ever eaten chocolate, I just want to give everyone a block of it and be like DUDE HOW AMAZING IS THIS?!
To quote my build instructions for my PC, just me thinking out loud to myself in a commented-out line
# These people amaze me
And I want everyone to know about it. Pipewire+SOFA is the absolute duck's nuts.