{"id":16072,"date":"2026-03-24T06:53:24","date_gmt":"2026-03-24T06:53:24","guid":{"rendered":"https:\/\/sistc.com\/?p=16072"},"modified":"2026-06-16T09:26:47","modified_gmt":"2026-06-16T09:26:47","slug":"dual-microphone-array-beamforming-design","status":"publish","type":"post","link":"https:\/\/sistc.com\/zh\/dual-microphone-array-beamforming-design\/","title":{"rendered":"\u53cc\u9ea6\u514b\u98ce\u9635\u5217\u8bbe\u8ba1\uff1a\u76f8\u4f4d\u5dee\u3001\u6ce2\u675f\u6210\u5f62\u548c\u5de5\u7a0b\u6743\u8861"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">In Part 1, we introduced the fundamentals of microphone arrays and beamforming.<br>Now, we move into the <strong>engineering core<\/strong>\u2014how a <strong>2-microphone (dual-mic) array actually works<\/strong>, and why it remains the foundation of most modern voice systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Despite its simplicity, the dual-mic array reveals nearly all the critical principles behind advanced array architectures.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Why Start with a 2-Microphone Array?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A microphone array can consist of dozens\u2014or even hundreds\u2014of elements.<br>However, every complex array can be reduced to interactions between <strong>pairs of microphones<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This makes the dual-mic array the <strong>fundamental building block<\/strong> for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Smart speakers<\/li>\n\n\n\n<li>AI voice modules<\/li>\n\n\n\n<li>Wearables<\/li>\n\n\n\n<li>Automotive voice systems<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">At SISTC, many optimized solutions begin with <strong>dual-MEMS microphone architectures<\/strong>, then scale into multi-channel arrays.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 Explore our MEMS microphone portfolio:<br><a href=\"https:\/\/sistc.com\/product-category\/mems-microphone\/\">https:\/\/sistc.com\/product-category\/mems-microphone\/<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The Key Concept: Phase Difference<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When a sound wave reaches two microphones placed at a distance <strong>D<\/strong>, it arrives at slightly different times.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This creates a <strong>phase difference<\/strong>, which determines whether signals:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reinforce each other (constructive interference)<\/li>\n\n\n\n<li>Cancel each other (destructive interference)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">What affects phase difference?<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Microphone spacing (D)<\/li>\n\n\n\n<li>Sound frequency (\u03bb)<\/li>\n\n\n\n<li>Arrival angle (\u03b8)<\/li>\n\n\n\n<li>Applied delay (\u03c4)<\/li>\n\n\n\n<li>Phase inversion (\u03c1)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This relationship is the <strong>core mechanism behind beamforming<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Two Fundamental Array Types<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Dual-mic arrays can operate in two main modes:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Additive Array (Summation Mode)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Working principle:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Signals are added together<\/li>\n\n\n\n<li>Optional time delay aligns signals from a target direction<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Characteristics:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Flat frequency response (on-axis)<\/li>\n\n\n\n<li>Strong signal gain<\/li>\n\n\n\n<li>Directionality depends on frequency<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">Typical configurations:<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Broadside array<\/li>\n\n\n\n<li>Endfire array<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. Differential Array (Subtraction Mode)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Working principle:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>One signal is inverted and subtracted<\/li>\n\n\n\n<li>Output = difference between microphones<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Characteristics:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Strong directionality even at low frequencies<\/li>\n\n\n\n<li>Built-in noise suppression<\/li>\n\n\n\n<li>Limited bandwidth (low-frequency roll-off + high-frequency aliasing)<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Broadside vs Endfire: Directional Behavior<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Broadside Array<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Maximum sensitivity <strong>perpendicular<\/strong> to mic axis<\/li>\n\n\n\n<li>Symmetrical pickup pattern<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Endfire Array<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Maximum sensitivity <strong>along the mic axis<\/strong><\/li>\n\n\n\n<li>Strong forward focus<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 Endfire arrays are widely used in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Smart speakers<\/li>\n\n\n\n<li>Voice assistants<\/li>\n\n\n\n<li>Automotive cabins<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">From Omni to Cardioid: Pattern Formation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">By adjusting delay and phase, dual-mic arrays can create classic directional patterns:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Pattern<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>Omnidirectional<\/td><td>Equal sensitivity in all directions<\/td><\/tr><tr><td>Dipole (Figure)<\/td><td>Two opposite lobes<\/td><\/tr><tr><td>Cardioid<\/td><td>Forward-focused pickup<\/td><\/tr><tr><td>Supercardioid<\/td><td>Narrower front lobe<\/td><\/tr><tr><td>Hypercardioid<\/td><td>Highest directivity<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"624\" height=\"351\" src=\"https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Array-factor-of-two-element-differential-end-fire-array.png\" alt=\"\" class=\"wp-image-16073\" srcset=\"https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Array-factor-of-two-element-differential-end-fire-array.png 624w, https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Array-factor-of-two-element-differential-end-fire-array-300x169.png 300w, https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Array-factor-of-two-element-differential-end-fire-array-18x10.png 18w, https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Array-factor-of-two-element-differential-end-fire-array-600x338.png 600w\" sizes=\"(max-width: 624px) 100vw, 624px\" \/><figcaption class=\"wp-element-caption\">Array factor of two-element differential end-fire array<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">These patterns are essential for <strong>voice isolation in noisy environments<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">SNR Improvement in Dual-Mic Arrays<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A key advantage of dual-mic arrays is <strong>SNR enhancement<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When signals align:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Signal power increases by <strong>+6 dB<\/strong><\/li>\n\n\n\n<li>Noise power increases by <strong>+3 dB<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 Net improvement:<br><strong>+3 dB SNR gain<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is critical for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Far-field voice pickup<\/li>\n\n\n\n<li>Low-power AI devices<\/li>\n\n\n\n<li>Edge computing systems<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">The Trade-offs Engineers Must Consider<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Designing a dual-mic array involves multiple trade-offs:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Microphone Spacing (D)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Larger spacing \u2192 better directionality<\/li>\n\n\n\n<li>But \u2192 earlier spatial aliasing<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"561\" height=\"316\" src=\"https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Dual-element-array-microphone-building-unit.jpg\" alt=\"\" class=\"wp-image-16061\" srcset=\"https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Dual-element-array-microphone-building-unit.jpg 561w, https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Dual-element-array-microphone-building-unit-300x169.jpg 300w, https:\/\/sistc.com\/wp-content\/uploads\/2026\/03\/Dual-element-array-microphone-building-unit-18x10.jpg 18w\" sizes=\"(max-width: 561px) 100vw, 561px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">2. Frequency Dependency<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Additive arrays:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Lose directionality at low frequencies<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Differential arrays:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Maintain directionality<\/li>\n\n\n\n<li>But suffer from bandwidth limitations<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. Noise Sensitivity<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Differential arrays:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>More sensitive to mismatch between microphones<\/li>\n\n\n\n<li>Require precise calibration<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. Implementation Complexity<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Adding:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Time delay<\/li>\n\n\n\n<li>Phase control<\/li>\n\n\n\n<li>Gain weighting<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">increases system complexity\u2014especially in real-time AI applications.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How SISTC Optimizes Dual-Mic Performance<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">At SISTC, we go beyond basic array design by integrating:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 High-consistency MEMS microphones<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tight sensitivity matching<\/li>\n\n\n\n<li>Low self-noise<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Advanced noise reduction algorithms<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Adaptive filtering<\/li>\n\n\n\n<li>AI-based voice enhancement<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Hardware + software co-design<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Signal conditioning circuits<\/li>\n\n\n\n<li>Embedded processing modules<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 Explore our integrated solutions:<br><a href=\"https:\/\/sistc.com\/product-category\/sensor-module\/\">https:\/\/sistc.com\/product-category\/sensor-module\/<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Real-World Applications<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Dual-mic arrays are widely used in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Smart home voice control<\/li>\n\n\n\n<li>Bluetooth headsets<\/li>\n\n\n\n<li>Automotive voice systems<\/li>\n\n\n\n<li>Industrial voice interfaces<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">They provide an optimal balance between:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Performance<\/li>\n\n\n\n<li>Cost<\/li>\n\n\n\n<li>Power consumption<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The dual-microphone array is the <strong>foundation of modern beamforming systems<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By leveraging:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Phase difference<\/li>\n\n\n\n<li>Time delay<\/li>\n\n\n\n<li>Signal subtraction<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">it enables:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Directional audio capture<\/li>\n\n\n\n<li>Noise suppression<\/li>\n\n\n\n<li>Efficient voice interaction<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">In the next article, we will explore how <strong>multi-element arrays (N-mic systems)<\/strong> dramatically enhance performance\u2014and what it takes to design them effectively.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><a href=\"http:\/\/references\/\">References<\/a><\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Analog Devices application note AN-1328, available at&nbsp;<a href=\"https:\/\/www.analog.com\/media\/en\/technical-documentation\/application-notes\/AN-1328.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/www.analog.com\/media\/en\/technical-documentation\/application-notes\/AN-1328.pdf<\/a>&nbsp;[accessed June 2021]. Describes principle of operation, design, and construction of professional grade studio or live performance microphone using up to 32 analog MEMS microphones connected to op amps and a difference amplifier. Design is a volumetric array consisting of two additive broadside arrays in a differential end-fire configuration.<\/li>\n\n\n\n<li>TDK InvenSense applicaton note AN-1140, available at&nbsp;<a href=\"https:\/\/invensense.tdk.com\/wp-content\/uploads\/2015\/02\/Microphone-Array-Beamforming.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/invensense.tdk.com\/wp-content\/uploads\/2015\/02\/Microphone-Array-Beamforming.pdf<\/a>&nbsp;[accessed June 2021]. Discusses basic principles and performance of various array configurations.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In Part 1, we introduced the fundamentals of microphone arrays and beamforming.Now, we move into the engineering core\u2014how a 2-microphone (dual-mic) array actually works, and why it remains the foundation [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_joinchat":[],"footnotes":""},"categories":[103],"tags":[],"class_list":["post-16072","post","type-post","status-publish","format-standard","hentry","category-technical-blog"],"_links":{"self":[{"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/posts\/16072","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/comments?post=16072"}],"version-history":[{"count":1,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/posts\/16072\/revisions"}],"predecessor-version":[{"id":16475,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/posts\/16072\/revisions\/16475"}],"wp:attachment":[{"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/media?parent=16072"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/categories?post=16072"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sistc.com\/zh\/wp-json\/wp\/v2\/tags?post=16072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}