{"id":159,"date":"2019-04-24T23:44:03","date_gmt":"2019-04-25T06:44:03","guid":{"rendered":"http:\/\/eequalspi.com\/?p=159"},"modified":"2019-04-24T23:44:03","modified_gmt":"2019-04-25T06:44:03","slug":"microphone-polar-plots","status":"publish","type":"post","link":"https:\/\/eequalspi.com\/index.php\/2019\/04\/24\/microphone-polar-plots\/","title":{"rendered":"Microphone Polar Plots"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">For a while, I&#8217;ve been thinking about noise cancelling microphones.  I realized the other day that in order to ever hope to build one, I needed to model it first. What I ended up doing was building a model in matlab (of course), which includes the following simple classes:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"560\" height=\"420\" src=\"http:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/Delay.png\" alt=\"\" class=\"wp-image-160\" srcset=\"https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/Delay.png 560w, https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/Delay-300x225.png 300w\" sizes=\"auto, (max-width: 560px) 85vw, 560px\" \/><\/figure>\n\n\n\n<ol class=\"wp-block-list\"><li>A waveform class to allow for quick generation of sine waves.<\/li><li>A wavesource class to allow positioning of those waveforms in space.<\/li><li>A microphone class to generate wave recievers positioned in space, which computes the distance between itself and the source in order to phase shift the incoming wave.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Then, to get waveforms, you can take the output audio from multiple microphones (which is effectively time aligned) and do math with it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then, by sweeping the wave sources through space, we can plot the pickup patterns of different wave forms.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"560\" height=\"420\" src=\"http:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarPlot.png\" alt=\"\" class=\"wp-image-161\" srcset=\"https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarPlot.png 560w, https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarPlot-300x225.png 300w\" sizes=\"auto, (max-width: 560px) 85vw, 560px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">By sweeping the frequency of the waveform over successive sweeps, we can see that impact as well.<br><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"881\" height=\"661\" src=\"http:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarSweep.png\" alt=\"\" class=\"wp-image-162\" srcset=\"https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarSweep.png 881w, https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarSweep-300x225.png 300w, https:\/\/eequalspi.com\/wp-content\/uploads\/2019\/04\/polarSweep-768x576.png 768w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Fun. More to come?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Get the code here: <a href=\"https:\/\/github.com\/wespo\/DirectionalMicrophone\">https:\/\/github.com\/wespo\/DirectionalMicrophone<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>For a while, I&#8217;ve been thinking about noise cancelling microphones. I realized the other day that in order to ever hope to build one, I needed to model it first. What I ended up doing was building a model in matlab (of course), which includes the following simple classes: A waveform class to allow for &hellip; <a href=\"https:\/\/eequalspi.com\/index.php\/2019\/04\/24\/microphone-polar-plots\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Microphone Polar Plots&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[14,15,13],"class_list":["post-159","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-audio","tag-microphone","tag-noise-cancelling"],"_links":{"self":[{"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/posts\/159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/comments?post=159"}],"version-history":[{"count":1,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/posts\/159\/revisions"}],"predecessor-version":[{"id":163,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/posts\/159\/revisions\/163"}],"wp:attachment":[{"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/media?parent=159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/categories?post=159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/eequalspi.com\/index.php\/wp-json\/wp\/v2\/tags?post=159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}