I’d like to try share explanation of CMSS-3D and the “down mixing” that makes the Katana and other Virtual Surround Sound products by Creative, and what makes them special.
Creative has made sound products and DSPs that use HRTF’s (Head Related Transfer Function, which describes the way sound is split by our faces and bounced around our ears) for longer than a patent would last, and have some unique functionality. Let’s say we feed a Katana a 16-bit, 96 kHz, 5.1 channel sound input. If you imagine a 5.1 speaker setup in the living room, there are fairly large gaps inbetween speakers. Especially useful with games, the Creative DSP (now SBAxx-1) uses the information about how sound volume pans between these speakers to essentially guess positions between speakers, creating a “ring” of sound rather than just 5 funnels of direction. A 7.1 signal creates more accurate directionality, but a complete “ring” is the goal. Now, to simulate that surround sound ring, the DSP essentially converts any given clock position around this ring and applies the time delay between when your left ear and right ear would hear it (we humans only have 2 “input” channels), and creates a down mix with the time delays “baked in,” for whatever the output device, such as the Katana or headphones connected to the Katana. The signal remains 16-bit 96 kHz through this entire process, so there’s no downsampling.
Because Creative’s Virtual Surround solution is based on the math of HRTFs from any direction, it was actually able to utilize FULL 3D sound output back in the day when games would output such data, so you could have sounds coming from above (like Dolby Atmos and DTS-X) and below (imagine trying to set up speakers below the floor in a home theater!). Bioshock and Borderlands 2 were really cool in 3D surround, and can you imagine 3D surround in flight sims, horror games, or adventure games? Fortunately, 3D audio is starting to make a comeback with some Virtual Reality titles, but 3D audio by itself is much more accessible for those with budget or motion sickness constraints, and does a great job of expanding the environment and immersion beyond the screen in front of you.
Creative has made sound products and DSPs that use HRTF’s (Head Related Transfer Function, which describes the way sound is split by our faces and bounced around our ears) for longer than a patent would last, and have some unique functionality. Let’s say we feed a Katana a 16-bit, 96 kHz, 5.1 channel sound input. If you imagine a 5.1 speaker setup in the living room, there are fairly large gaps inbetween speakers. Especially useful with games, the Creative DSP (now SBAxx-1) uses the information about how sound volume pans between these speakers to essentially guess positions between speakers, creating a “ring” of sound rather than just 5 funnels of direction. A 7.1 signal creates more accurate directionality, but a complete “ring” is the goal. Now, to simulate that surround sound ring, the DSP essentially converts any given clock position around this ring and applies the time delay between when your left ear and right ear would hear it (we humans only have 2 “input” channels), and creates a down mix with the time delays “baked in,” for whatever the output device, such as the Katana or headphones connected to the Katana. The signal remains 16-bit 96 kHz through this entire process, so there’s no downsampling.
Because Creative’s Virtual Surround solution is based on the math of HRTFs from any direction, it was actually able to utilize FULL 3D sound output back in the day when games would output such data, so you could have sounds coming from above (like Dolby Atmos and DTS-X) and below (imagine trying to set up speakers below the floor in a home theater!). Bioshock and Borderlands 2 were really cool in 3D surround, and can you imagine 3D surround in flight sims, horror games, or adventure games? Fortunately, 3D audio is starting to make a comeback with some Virtual Reality titles, but 3D audio by itself is much more accessible for those with budget or motion sickness constraints, and does a great job of expanding the environment and immersion beyond the screen in front of you.