On Saturday, September 17, 2016 at 1:52:59 PM UTC-4, Max wrote:> A lot of the CPU-economical algorithms that I've seen call for slow > variations in delays, etc to avoid perception of repeating patterns or > resonances. I haven't experimented with that aspect, so I don't know > if the LFO patterns themselves could be perceived. It seems like it > could lend an unrealistic sound though. > > The techniques that I've been curious about are: > FDN: Feedback Delay Networks > DWN: Digital Waveguide Networks > Waveguide Mesh methods > SDN: Scattering Delay Networks > > The latter was featured in a paper by Enzo De Sena and Julius O Smoth, > "Efficient Synthesis of Room Acoustic via Scattering Delay Networks": > > https://arxiv.org/pdf/1502.05751.pdf > > That references other papers by Vorlander, Savioja, and others, that > feature some of the other approaches above. > > I was curious about whether anyone has experimented with those.Seems interesting but unfortunately one needs to buy the article to access the media. How does it sound?
Anatomy of a reverb algorithm
Started by ●September 14, 2016
Reply by ●November 15, 20162016-11-15
Reply by ●November 17, 20162016-11-17
On Tue, 15 Nov 2016 06:33:39 -0800 (PST), Bruno Afonso <bafonso@gmail.com> wrote:>On Saturday, September 17, 2016 at 1:52:59 PM UTC-4, Max wrote: > >> A lot of the CPU-economical algorithms that I've seen call for slow >> variations in delays, etc to avoid perception of repeating patterns or >> resonances. I haven't experimented with that aspect, so I don't know >> if the LFO patterns themselves could be perceived. It seems like it >> could lend an unrealistic sound though. >> >> The techniques that I've been curious about are: >> FDN: Feedback Delay Networks >> DWN: Digital Waveguide Networks >> Waveguide Mesh methods >> SDN: Scattering Delay Networks >> >> The latter was featured in a paper by Enzo De Sena and Julius O Smoth, >> "Efficient Synthesis of Room Acoustic via Scattering Delay Networks": >> >> https://arxiv.org/pdf/1502.05751.pdf >> >> That references other papers by Vorlander, Savioja, and others, that >> feature some of the other approaches above. >> >> I was curious about whether anyone has experimented with those. > >Seems interesting but unfortunately one needs to buy the article to access the media. How does it sound?The paper came up for me back when I was initially searching for info. Maybe they've locked it down since then. SDNs are a simplified version of waveguide networks, and given the objective of running in realtime (video games, VR, etc), I was surprised that it would work at all in realtime. DWN's are notorious CPU hogs. I have seen some sites that had samples online. Don't have the URLs handy at the moment but I'll try to locate them again later. I thought the sound was pretty good, considering that they're only accurately simulating the first wall reflections. I'm not sure how they're doing subsequent 2nd order and higher, but I get the impression that they reuse the same waveguide that was used for the first reflections. I'd love to know more about how that could work. I've also heard one demo where it seemed like percussive events would trigger resonant peaks. So perhaps more video game apps than hifi, or maybe the demo itself had problems.
