{"id":4295,"date":"2019-06-14T01:08:09","date_gmt":"2019-06-13T23:08:09","guid":{"rendered":"https:\/\/demdlx704as001.ad.harman.com\/?p=4295"},"modified":"2019-12-13T14:47:59","modified_gmt":"2019-12-13T13:47:59","slug":"biquad-3","status":"publish","type":"post","link":"https:\/\/audioworx.transfunnel.co\/old\/?p=4295","title":{"rendered":"Biquad"},"content":{"rendered":"<p class=\"text\">This object computes bi-quadratic filter coefficients and calculates the output of the input audio buffers<br \/>\nprocessed through the filters that users specify.<\/p>\n<p class=\"text\">From SFD, the user can select what type of filtering to carry out via the &#8220;Biquad Topology field&#8221;:<\/p>\n<ul class=\"bullet-points\">\n<li>Direct Form I<\/li>\n<li>Direct Form II<\/li>\n<li>Transposed Direct Form II<\/li>\n<\/ul>\n<p class=\"text\">This object operates in one of the six modes:<\/p>\n<ul class=\"bullet-points\">\n<li><span class=\"emph\">Parameter Mode<\/span> \u2013 This mode generates a set of filters per channel, so each channel has its own set of unique filters.<\/li>\n<li><span class=\"emph\">Crossover Mode<\/span> \u2013 This mode generates a set of filters in the order of one through four per channel.<\/li>\n<li><span class=\"emph\">Coefficient Mode<\/span> \u2013 In this mode, the object does not generate any filter coefficients \u2013 it simply receives them from the tuning tool.<\/li>\n<li><span class=\"emph\">Parameter One Mode<\/span> \u2013 This mode generates a set of filter coefficients for all audio channels. The only difference between this mode and the Parameter mode is that this mode generates one set of coefficients for all channels as opposed to one set per channel.<\/li>\n<li><span class=\"emph\">Parameter One Mode Set Control Frequenc<\/span>y \u2013 This mode only uses one filter and applies the filter characteristics to all channels as does the Parameter One Mode above. It also exposes one control (accessible from the HU) variable to manipulate the cut-off frequency.<\/li>\n<li><span class=\"emph\">Coefficient One Mode<\/span> \u2013 This mode generates a single set of filter coefficients for all audio channels. The only difference between this mode and the Coefficient mode is that this mode generates one set of coefficients for all channels as opposed to one set per channel.<\/li>\n<li><span class=\"emph\">Equalizer Mode<\/span> \u2013 This mode generates a unique set of filters for every channel.<\/li>\n<li><span class=\"emph\">Equalizer One Mode<\/span> \u2013 This mode generates a single set of filters for all audio channels. The difference between this mode and Equalizer mode is that this mode generates a unique set of filters for all channels as opposed to one set per channel.<\/li>\n<\/ul>\n<p class=\"text\">Equalizer modes support ramping functionality whenever filter type or parameters change at run-time.<br \/>\nRamping variables are based on sampling rate, block length and ramp time. Implemented ramping strategy is<br \/>\nbased on first-order low-pass interpolation scheme.<\/p>\n<p class=\"text\">In the SFD, users can set the number of channels (the number of input and output channels is the same) as<br \/>\nwell as the number of filters. Users can also select the object corresponding to the required mode.<\/p>\n<p class=\"text\">In the GTT, the object exposes several of its variables based on mode:<\/p>\n<p class=\"text\"><span class=\"emph\">Parameter Mode <\/span>\u2013 For each filter in each channel, the object exposes:<\/p>\n<ul class=\"bullet-points\">\n<li>Frequency (cut-off)<\/li>\n<li>Gain (in dB)<\/li>\n<li>\u00a0Q-value<\/li>\n<li>\u00a0Type of filter:\n<ul class=\"bullet-points\">\n<li>All pass 1<\/li>\n<li>All pass 2<\/li>\n<li>High pass 1<\/li>\n<li>High pass 2<\/li>\n<li>Low pass 1<\/li>\n<li>Low pass 2<\/li>\n<li>High shelf 1<\/li>\n<li>High shelf 2<\/li>\n<li>Low shelf 1<\/li>\n<li>Low shelf 2<\/li>\n<li>Parametric (Peaking)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p class=\"text\">If using the GTT (specifically) for tuning, these additional types of filters are available:<\/p>\n<ul class=\"bullet-points\">\n<li style=\"list-style-type: none;\">\n<ul class=\"bullet-points\">\n<li>High pass Butterworth 3<\/li>\n<li>High pass Bessel 3<\/li>\n<li>High pass Butterworth 4<\/li>\n<li>High pass Bessel 4<\/li>\n<li>High pass Linkwitz-Riley 4<\/li>\n<li>Low pass Butterworth 3<\/li>\n<li>Low pass Bessel 3<\/li>\n<li>Low pass Butterworth 4<\/li>\n<li>Low pass Bessel 4<\/li>\n<li>Low pass Linkwitz-Riley 4<\/li>\n<\/ul>\n<\/li>\n<li>Bypass (on\/off)<\/li>\n<\/ul>\n<p class=\"text\"><strong>Crossover Mode<\/strong> \u2013 For each filter in each channel, the object exposes:<\/p>\n<ul class=\"bullet-points\">\n<li>Frequency (Cut-off)<\/li>\n<li>Type of filter\n<ul>\n<li>Bypass<\/li>\n<li>High pass 1<\/li>\n<li>High pass Butterworth 2<\/li>\n<li>High pass Bessel 2<\/li>\n<li>High pass Linkwitz Riley 2<\/li>\n<li>High pass Butterworth 3<\/li>\n<li>High pass Bessel 3<\/li>\n<li>High pass Butterworth 4<\/li>\n<li>High pass Bessel 4<\/li>\n<li>Low pass Linkwitz-Riley 4<\/li>\n<li>Low pass 1<\/li>\n<li>Low pass Butterworth 2<\/li>\n<li>Low pass Bessel 2<\/li>\n<li>Low pass Linkwitz Riley 2<\/li>\n<li>Low pass Butterworth 3<\/li>\n<li>Low pass Bessel 3<\/li>\n<li>Low pass Butterworth 4<\/li>\n<li>Low pass Bessel 4<\/li>\n<li>Low pass Linkwitz-Riley 4<\/li>\n<\/ul>\n<\/li>\n<li>Bypass (on\/off)<\/li>\n<\/ul>\n<p class=\"text\"><strong>Coefficient Mode<\/strong> \u2013 For each filter per channel, these five values representing filter coefficients are exposed:<\/p>\n<ul class=\"bullet-points\">\n<li class=\"text\">b0<\/li>\n<li class=\"text\">b1<\/li>\n<li class=\"text\">b2<\/li>\n<li class=\"text\">a1<\/li>\n<li class=\"text\">a2<\/li>\n<\/ul>\n<p class=\"text\"><strong>Parameter One Mode<\/strong> \u2013 This is identical to the Parameter Mode, except, instead of presenting the variables for each filter per channel, this mode only presents a set of coefficients per filter, regardless of the number of<br \/>\nchannels.<\/p>\n<p class=\"text\"><strong>Parameter One Mode Set Control Frequency <\/strong>\u2013 This is identical to Parameter One Mode but it has only one filter.<br \/>\nThe Biquad object does not expose any variables for control except for the <strong>Parameter One Mode Set Control Frequency<\/strong>, where it exposes the cut-off frequency of the filter.<\/p>\n<p class=\"text\"><strong>Coefficient One Mode<\/strong> \u2013 For each filter regardless of the number of channels, below five values representing<br \/>\nfilter coefficients are exposed:<\/p>\n<ul class=\"bullet-points\">\n<li class=\"text\">b0<\/li>\n<li class=\"text\">b1<\/li>\n<li class=\"text\">b2<\/li>\n<li class=\"text\">a1<\/li>\n<li class=\"text\">a2<\/li>\n<\/ul>\n<p class=\"text\"><strong>Equalizer Mode<\/strong> \u2013 For each filter in each channel, the object exposes the following parameters for both tuning and state-tuning:<\/p>\n<ul class=\"bullet-points\">\n<li class=\"text\">Frequency (in Hz)<\/li>\n<li class=\"text\">Gain (in dB)<\/li>\n<li class=\"text\">Q-value<\/li>\n<li class=\"text\">Type of filter:\n<ul>\n<li>Bypass<\/li>\n<li>Bypass<\/li>\n<li>All pass 1<\/li>\n<li>All pass 2<\/li>\n<li>High pass 1<\/li>\n<li>High pass 2<\/li>\n<li>Low pass 1<\/li>\n<li>Low pass 2<\/li>\n<li>High shelf 1<\/li>\n<li>High shelf 2<\/li>\n<li>Low shelf 1<\/li>\n<li>Low shelf 2<\/li>\n<li>Parameteric<\/li>\n<li>Bandpass<\/li>\n<li>Bandstop<\/li>\n<li>Amplifier<\/li>\n<li>Resonant<\/li>\n<li>Bell<\/li>\n<li>Low shelf variable-slope<\/li>\n<li>High shelf variable-slope<\/li>\n<li>Peaking GEQ<\/li>\n<li>Peaking HPro<\/li>\n<li>Low shelf HPro<\/li>\n<li>High shelf HPro<\/li>\n<li>Peaking AFS<\/li>\n<li>Peaking PA Plus<\/li>\n<li>Peaking Crown<\/li>\n<li>Low shelf PA Plus<\/li>\n<li>High shelf PA Plus<\/li>\n<\/ul>\n<\/li>\n<li class=\"text\">Bypass (on\/off)<\/li>\n<li class=\"text\">Width (in octaves- only for Bell filter)<\/li>\n<li class=\"text\">Asymmetry (on\/ off- only for Bell filter)<\/li>\n<li class=\"text\">Slope (in dB per octave- only for variable-slope low\/ high shelving filters)<\/li>\n<\/ul>\n<p class=\"text\"><strong>Equalizer One Mode<\/strong> \u2013 This is identical to the <strong>Equalizer Mod<\/strong>e. Except, instead of specifying the parameters for each filter per channel, this mode specifies the same set of coefficients per filter, regardless of the number of<br \/>\nchannels.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This object computes bi-quadratic filter coefficients and calculates the output of the input audio buffers processed through the filters that users specify. From SFD, the user can select what type of filtering to carry out via the &#8220;Biquad Topology field&#8221;: Direct Form I Direct Form II Transposed Direct Form II This object operates in one [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ocean_post_layout":"","ocean_both_sidebars_style":"","ocean_both_sidebars_content_width":0,"ocean_both_sidebars_sidebars_width":0,"ocean_sidebar":"0","ocean_second_sidebar":"0","ocean_disable_margins":"enable","ocean_add_body_class":"","ocean_shortcode_before_top_bar":"","ocean_shortcode_after_top_bar":"","ocean_shortcode_before_header":"","ocean_shortcode_after_header":"","ocean_has_shortcode":"","ocean_shortcode_after_title":"","ocean_shortcode_before_footer_widgets":"","ocean_shortcode_after_footer_widgets":"","ocean_shortcode_before_footer_bottom":"","ocean_shortcode_after_footer_bottom":"","ocean_display_top_bar":"default","ocean_display_header":"default","ocean_header_style":"","ocean_center_header_left_menu":"0","ocean_custom_header_template":"0","ocean_custom_logo":0,"ocean_custom_retina_logo":0,"ocean_custom_logo_max_width":0,"ocean_custom_logo_tablet_max_width":0,"ocean_custom_logo_mobile_max_width":0,"ocean_custom_logo_max_height":0,"ocean_custom_logo_tablet_max_height":0,"ocean_custom_logo_mobile_max_height":0,"ocean_header_custom_menu":"0","ocean_menu_typo_font_family":"0","ocean_menu_typo_font_subset":"","ocean_menu_typo_font_size":0,"ocean_menu_typo_font_size_tablet":0,"ocean_menu_typo_font_size_mobile":0,"ocean_menu_typo_font_size_unit":"px","ocean_menu_typo_font_weight":"","ocean_menu_typo_font_weight_tablet":"","ocean_menu_typo_font_weight_mobile":"","ocean_menu_typo_transform":"","ocean_menu_typo_transform_tablet":"","ocean_menu_typo_transform_mobile":"","ocean_menu_typo_line_height":0,"ocean_menu_typo_line_height_tablet":0,"ocean_menu_typo_line_height_mobile":0,"ocean_menu_typo_line_height_unit":"","ocean_menu_typo_spacing":0,"ocean_menu_typo_spacing_tablet":0,"ocean_menu_typo_spacing_mobile":0,"ocean_menu_typo_spacing_unit":"","ocean_menu_link_color":"","ocean_menu_link_color_hover":"","ocean_menu_link_color_active":"","ocean_menu_link_background":"","ocean_menu_link_hover_background":"","ocean_menu_link_active_background":"","ocean_menu_social_links_bg":"","ocean_menu_social_hover_links_bg":"","ocean_menu_social_links_color":"","ocean_menu_social_hover_links_color":"","ocean_disable_title":"default","ocean_disable_heading":"default","ocean_post_title":"","ocean_post_subheading":"","ocean_post_title_style":"","ocean_post_title_background_color":"","ocean_post_title_background":0,"ocean_post_title_bg_image_position":"","ocean_post_title_bg_image_attachment":"","ocean_post_title_bg_image_repeat":"","ocean_post_title_bg_image_size":"","ocean_post_title_height":0,"ocean_post_title_bg_overlay":0.5,"ocean_post_title_bg_overlay_color":"","ocean_disable_breadcrumbs":"default","ocean_breadcrumbs_color":"","ocean_breadcrumbs_separator_color":"","ocean_breadcrumbs_links_color":"","ocean_breadcrumbs_links_hover_color":"","ocean_display_footer_widgets":"default","ocean_display_footer_bottom":"default","ocean_custom_footer_template":"0","footnotes":"","ocean_post_oembed":"","ocean_post_self_hosted_media":"","ocean_post_video_embed":"","ocean_link_format":"","ocean_link_format_target":"self","ocean_quote_format":"","ocean_quote_format_link":"post","ocean_gallery_link_images":"off","ocean_gallery_id":[]},"categories":[81,10],"tags":[],"coauthors":[165],"_links":{"self":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/4295"}],"collection":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4295"}],"version-history":[{"count":10,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/4295\/revisions"}],"predecessor-version":[{"id":10601,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/4295\/revisions\/10601"}],"wp:attachment":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4295"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcoauthors&post=4295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}