{"id":3789,"date":"2019-06-12T09:15:51","date_gmt":"2019-06-12T07:15:51","guid":{"rendered":"https:\/\/demdlx704as001.ad.harman.com\/?p=3789"},"modified":"2022-07-15T08:33:46","modified_gmt":"2022-07-15T06:33:46","slug":"ir-viewer-options","status":"publish","type":"post","link":"https:\/\/audioworx.transfunnel.co\/old\/?p=3789","title":{"rendered":"Legacy Viewer &#8211; Viewer Options"},"content":{"rendered":"<p class=\"text\">Within the impulse response viewer is possible to modify some parameters to improve the presentation of the IR and the relative transfer function.\u00a0Click on the settings icon of the relative chart.<\/p>\n<p class=\"text\">For the Impulse response, it is possible to cut the IR and window it.<\/p>\n<p class=\"text\"><img fetchpriority=\"high\" decoding=\"async\" class=\"medium-image alignnone wp-image-9194 size-full\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/window_signal.png\" alt=\"\" width=\"593\" height=\"569\" \/><\/p>\n<ul class=\"bullet-points\">\n<li><strong>start<\/strong>, in seconds.\u00a0 The start cut of the IR<\/li>\n<li><strong>end<\/strong>, in seconds.\u00a0 The end cut of the IR<\/li>\n<li><strong>Win Left Name<\/strong>, the window applied to the left side of the cut (see image below)<\/li>\n<li><strong>Win Left in Sec<\/strong>, the length of the left side window in seconds<\/li>\n<li><strong>Win Right Name<\/strong>, the window applied to the right\u00a0 side of the cut<\/li>\n<li><strong>Win Right in Sec<\/strong>, the length of the right side window in seconds<img decoding=\"async\" class=\"alignnone wp-image-3796 big-image\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/MMTransferFunction.png\" alt=\"\" width=\"602\" height=\"408\" \/><\/li>\n<li>Calibration Selection type<br \/>\nFor IR three types of calibration, accordingly to <a href=\"https:\/\/confluence.harman.com\/confluence\/download\/attachments\/59059942\/HATSUserManual.pdf?api=v2\">hats manual<\/a>, p.39<span class=\"confluence-embedded-file-wrapper confluence-embedded-manual-size\"><img decoding=\"async\" class=\"alignnone wp-image-9198\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/hats_cal_relation.png\" alt=\"\" width=\"853\" height=\"298\" \/><\/span><\/p>\n<ol>\n<li>Digital Values: the compensation constant are not considered, the results and the units are in a.u. (arbitrary unit) <strong><br \/>\nHATS equivalent Transfer Function v\/v (small v doesn&#8217;t stand for volt!).<br \/>\n<\/strong><em><em>In MM this is called arbitrary unit a.u. and it is displayed as dBFS<\/em><\/em><\/li>\n<li>Arbitrary OUTPUT calibration (output calibration not yet implemented in GTT) as a workaround for proper Units in Transfer Function\u00a0 (H(f)) (0dBFS \u2192 1Vpk)<br \/>\n<strong>HATS equivalent, Normalized Sound Pressure Level Pa\/V<\/strong><\/li>\n<li>Calibration (removed stimulus), (Hpa(f)) to have a PASCAL outcome, independent from the generator<br \/>\n<strong>HATS equivalent, Sound Pressure Level Pa<\/strong><\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p><span class=\"confluence-embedded-file-wrapper confluence-embedded-manual-size\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-9197\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/calibration_explanation.png\" alt=\"\" width=\"667\" height=\"480\" \/><\/span><\/li>\n<\/ul>\n<p class=\"text\">The Transfer function options in the Frequency domain allows displaying the IR as transfer function in the complex frequency domain (magnitude+phase). Two methods are implemented:<\/p>\n<p class=\"text\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-13925\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/01.png\" alt=\"\" width=\"394\" height=\"287\" \/><\/p>\n<ul class=\"bullet-points\">\n<li><strong>Method<\/strong>, now is fixed to FULL (welch is deactivated and selected automatically for recordings).<\/li>\n<li><strong>FULL<\/strong> the power spectrum, or single-sided auto-spectrum, contains the squared RMS amplitudes of the signal. The signal cut and the windows selected in the time domain (see above) is fully transformed and its Power density calculated. There are no options, the frequency array is automatically computed, based on the next power of 2 of the IR length for an FFT, the frequency bins are calculated accordingly. This method also provides the phase of the TF<br \/>\nIt is also possible to select the smoothing for spectrum and phase. Pressing apply will update the chart.<\/li>\n<\/ul>\n<ul>\n<li><strong>Minimum bins<\/strong>, the minimum number of bins of the FFT. If the signal is larger of minimum bins an FFT zero-padded to the next power of 2 is computed.<\/li>\n<li><strong>Smoothing<\/strong> of spectrum and phase<\/li>\n<li><strong>Weighting <\/strong>is used to emphasize or suppress some aspects of a phenomenon compared to others, for measurement<\/li>\n<\/ul>\n<ul>\n<li class=\"text\"><strong>Wrap phase<\/strong>: if selected, limit the phase in the range -180\/180 degree.<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3801 big-image\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/MMTransferFunction1.png\" alt=\"\" width=\"572\" height=\"414\" \/><\/li>\n<\/ul>\n<ul class=\"bullet-points\">\n<li><strong>WELCH (DEACTIVATED FOR END USER)<\/strong>, computes an estimate of the power spectral density by dividing the data into overlapping segments, computing a modified periodogram for each segment and averaging the periodograms.<br \/>\nThis method doesn\u2019t provide the phase of the TF (a zero vector is generated instead)<br \/>\n<em>P. Welch, \u201cThe use of the fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms\u201d, IEEE Trans. Audio Electroacoust. vol. 15, pp. 70-73, 1967.<\/em><em><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3804 medium-image\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/MMTransferConfig1.png\" alt=\"\" width=\"395\" height=\"217\" \/><\/em><\/li>\n<\/ul>\n<ul class=\"bullet-points\">\n<li><strong>BINS per segment<\/strong>, number of points used to calculate the FFT of every segment in WELCH<br \/>\n<strong>Segment Overlap<\/strong>, Percent of Bins per segment to overlap between segments<\/li>\n<li><strong>Segment Window<\/strong>, the window used for conditioning every segment<\/li>\n<\/ul>\n<p class=\"text\">With the viewer it is possible to inspect and analyze the recording as well<\/p>\n<ul class=\"bullet-points\">\n<li>select <span class=\"emph\">Recorded<\/span> as signal type, length and windowing works as usual but are applied to the recording<\/li>\n<li><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8220 medium-image\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/10\/rec-options.png\" alt=\"\" width=\"476\" height=\"458\" \/><\/li>\n<li>Two possible spectrum processings are available for recorded signals\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li>The Usual Power Spectrum<\/li>\n<li><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-13926\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/power.png\" alt=\"\" width=\"436\" height=\"376\" \/><\/li>\n<li>A Constant Q transform based on <a href=\"https:\/\/librosa.github.io\/librosa\/generated\/librosa.core.cqt.html\">librosa\u00a0<\/a><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-13927\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/rtalike.png\" alt=\"\" width=\"430\" height=\"371\" \/><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>Both can change the slope of pink noise (detrend)<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-13928\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/06\/noise.png\" alt=\"\" width=\"452\" height=\"390\" \/><\/li>\n<\/ul>\n<ul class=\"bullet-points\">\n<li>WHITE FLAT (default, the power spectrum shows white noise as flat)<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9188\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/10\/PN-3dB.png\" alt=\"\" width=\"649\" height=\"236\" \/><\/li>\n<li>PINK FLAT compensates the -3dB\/oct behavior of ordinary pink noise (the same noise is detrended in the image). The power of the two spectrums is preserved.<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9187\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/10\/PN-Flat.png\" alt=\"\" width=\"645\" height=\"243\" \/><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"bullet-points\">\n<li>Available Calibrations are:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9201\" src=\"https:\/\/audioworx.transfunnel.co\/old\/wp-content\/uploads\/2019\/10\/rec_cal.png\" alt=\"\" width=\"532\" height=\"105\" \/><\/li>\n<\/ul>\n<ul class=\"bullet-points\">\n<li>Digital Values: the compensation constant are not considered, the results and the units are in a.u. (arbitrary unit) <strong><br \/>\n<\/strong><em>In MM this is called arbitrary unit a.u. and it is displayed as dBFS<\/em><\/li>\n<li>Calibration\u00a0<strong> Sound Pressure of the recording in Pa<\/strong><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Within the impulse response viewer is possible to modify some parameters to improve the presentation of the IR and the relative transfer function.\u00a0Click on the settings icon of the relative chart. For the Impulse response, it is possible to cut the IR and window it. start, in seconds.\u00a0 The start cut of the IR end, [&hellip;]<\/p>\n","protected":false},"author":17,"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":[163],"tags":[],"coauthors":[138],"_links":{"self":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/3789"}],"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\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3789"}],"version-history":[{"count":16,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/3789\/revisions"}],"predecessor-version":[{"id":17399,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=\/wp\/v2\/posts\/3789\/revisions\/17399"}],"wp:attachment":[{"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3789"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3789"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3789"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/audioworx.transfunnel.co\/old\/index.php?rest_route=%2Fwp%2Fv2%2Fcoauthors&post=3789"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}