{"id":483762,"date":"2026-06-09T11:15:07","date_gmt":"2026-06-09T11:15:07","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/483762\/"},"modified":"2026-06-09T11:15:07","modified_gmt":"2026-06-09T11:15:07","slug":"pico-driven-ultrasound-enables-scaled-acoustic-model-of-home-stereo","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/483762\/","title":{"rendered":"Pico-Driven Ultrasound Enables Scaled Acoustic Model Of Home Stereo"},"content":{"rendered":"

There are plenty of ways to get sound into your house: good old fashioned headphones, the Dolby surround setup we all lusted after back in the day, or the 21st century\u2019s ubiquitous soundbar, with its \u2018spatial audio\u2019 magic. Which will work in your space? If you were an audio engineer, you\u2019d set up listening area and use a microphone to map the space\u2013 but that would be thousands of points and sounds like tedium. [PlasmatronX] had a better idea: use Schlieren imaging to see the sound waves as the travel through the space. Schlieren imaging has trouble with audio frequencies, though, and imaging the entire living room was going to be difficult. So he scaled it all down\u2013 including the sound waves, by shifting to ultrasonic frequencies.<\/a><\/p>\n

He\u2019s using the usual mirror-and-razor Schlieren setup with an 8\u2033 telescope mirror\u2013 and if you don\u2019t know what that is, we did a deep dive<\/a> on this kind of optical flow visualizer a while back. Inside the circular imaging area where that lets him see density changes, he\u2019s set up what he calls a CAT\u2013 Computer Acoustic Tomography\u2013 array. It\u2019s a rig on a turntable he can set up ultrasonic transducers on, to match the various speaker setups he wants to test, and turn so he can see from all angles what the scaled-down waves are doing. To capture those waves, which aren\u2019t going to be standing still, he adds a stroboscope. All the ultrasound signals are being generated by a Pi Pico, and are scaled 4:1 in the frequency domain\u2013 that is, a high 10kHz whine becomes inaudible 40kHz. Those signals are fed through a DIY 8-channel amp into both ultrasonic transducers and larger \u2018cat-repellent speakers\u2019 from AliExpress.<\/p>\n

The microcontroller is actually a Pico 2W, which is using its \u201cW\u201d to communicate via Bluetooth with a Pi 4. That SBC is running the camera, the stepper for the turntable, and image processing, along with the timing for the audio signals. After that it\u2019s a matter of setting up a scaled down 7.1 surround setup and itty-bity soundbar, and test it on a (stuffed) guinea pig. Obviously you can see a big difference between the steered beams from the tiny soundbar and the true surround, but how that translates to listening pleasure will be at least somewhat subjective.<\/p>\n

What\u2019s less subjective is the obvious effect soft furnishings add to the simulation. Now he doesn\u2019t take the time to find a material that will scale the frequency response of a set of curtains, but we\u2019re not sure how much that matters. At 5kHz or 20kHz, they\u2019re going to deaden sound, and you can see that here, and you can see it\u2019s a much bigger deal for the shaped beams of the soundbar than it is for surround sound. In the end, [PlasmatronX] decides to stick to headphones, but the whole video<\/a> is very much worth watching, so we\u2019ve embeddded it below. If you want to try it yourself he\u2019s put his code on GitHub.<\/a><\/p>\n

Thanks to [PlasmatronX] for the tip!<\/p>\n","protected":false},"excerpt":{"rendered":"There are plenty of ways to get sound into your house: good old fashioned headphones, the Dolby surround…\n","protected":false},"author":2,"featured_media":483763,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[85,46,370,141],"class_list":["post-483762","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-il","tag-israel","tag-physics","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/483762","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=483762"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/483762\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/483763"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=483762"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=483762"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=483762"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}