{"id":2640,"date":"2012-09-09T12:38:43","date_gmt":"2012-09-09T12:38:43","guid":{"rendered":"http:\/\/www.audioexcite.com\/?p=2640"},"modified":"2018-12-14T15:13:19","modified_gmt":"2018-12-14T15:13:19","slug":"raal-140-15d-ribbon-tweeter-measurements","status":"publish","type":"post","link":"https:\/\/www.audioexcite.com\/?p=2640","title":{"rendered":"RAAL 140-15D Ribbon Tweeter Measurements!"},"content":{"rendered":"<p><a href=\"https:\/\/www.audioexcite.com\/?page_id=2523\">RAAL 140-15D Measurements!<\/a><\/p>\n<p>I\u2019ve made some extensive measurements on the RAAL 140-15D ribbon tweeter and before the measurements I installed brand new replacement ribbons in both the RAAL tweeter samples and tightened up the ribbons as in this instruction video from RAAL.<\/p>\n<p><iframe loading=\"lazy\" width=\"720\" height=\"540\" src=\"https:\/\/www.youtube.com\/embed\/bvylZF9eJOA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe><\/p>\n<p>As instructed, it worked perfectly. \ud83d\ude42<\/p>\n<p>Since it\u2019s possible to shape the frequency response both vertically and horizontally with the supplied \u201cfoam deflection pads\u201d, it seemed as the tweeter measurement setup could almost be done in an infinite number of variations.<\/p>\n<p>I finally decided and ended up with the following tweeter configurations:<\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DPN.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2649\" title=\"RAAL-140-15D-DPN\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DPN.jpg\" alt=\"\" width=\"298\" height=\"448\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DPN.jpg 298w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DPN-199x300.jpg 199w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP1.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2650\" title=\"RAAL-140-15D-DP1\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP1.jpg\" alt=\"\" width=\"298\" height=\"448\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP1.jpg 298w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP1-199x300.jpg 199w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP2.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2651\" title=\"RAAL-140-15D-DP2\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP2.jpg\" alt=\"\" width=\"298\" height=\"448\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP2.jpg 298w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP2-199x300.jpg 199w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP3.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2652\" title=\"RAAL-140-15D-DP3\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP3.jpg\" alt=\"\" width=\"298\" height=\"448\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP3.jpg 298w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-DP3-199x300.jpg 199w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><\/a><\/p>\n<p><strong>Upper Left:<\/strong> DPN = No \u201cdeflection pads\u201d.<br \/>\n<strong>Upper Right:<\/strong> DP1 = With \u201cdeflection pads\u201d and 7cm visible ribbon.<br \/>\n<strong>Lower Left:<\/strong> DP2 = With \u201cdeflection pads\u201d and 5cm visible ribbon.<br \/>\n<strong>Lower Right:<\/strong> DP3 = With \u201cdeflection pads\u201d and 3cm visible ribbon.<\/p>\n<p>The best overall balance and linearity between the horizontal and vertical frequency response is to use the \u201cdeflection pads\u201d in the <strong>DP1<\/strong> or <strong>DP2<\/strong> setting e.g. 7cm or 5cm visible ribbon.<\/p>\n<p>I wouldn\u2019t recommend using the RAAL ribbon without the \u201cfoam deflection pads\u201d. Without it the performance decreases in all aspects, both in frequency response and in distortion performance. Nevertheless I made a lot of measurements without the foam pads to have as a baseline to compare with.<\/p>\n<p>Even though the RAAL ribbon is a very robust ribbon tweeter I made all frequency measurements with a 44uF protection cap connected in series with it.<\/p>\n<p><strong>Flush-mounting or not?<\/strong><\/p>\n<p>I\u2019ve tested the RAAL ribbon with and without flush-mounting it on the baffle and the test results shows that there is no big diffraction problem and frequency response impact if it\u2019s not flush-mounted.<\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DPN.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2665\" title=\"RAAL 140-15D-1L flush vs noflush-- TW-axis 0deg DPN\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DPN.jpg\" alt=\"\" width=\"359\" height=\"121\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DPN.jpg 1117w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DPN-300x101.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DPN-1024x345.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP1.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2666\" title=\"RAAL 140-15D-1L flush vs noflush-- TW-axis 0deg DP1\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP1.jpg\" alt=\"\" width=\"359\" height=\"121\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP1.jpg 1117w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP1-300x101.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP1-1024x345.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP2.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2667\" title=\"RAAL 140-15D-1L flush vs noflush-- TW-axis 0deg DP2\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP2.jpg\" alt=\"\" width=\"359\" height=\"121\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP2.jpg 1117w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP2-300x101.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP2-1024x345.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP3.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2668\" title=\"RAAL 140-15D-1L flush vs noflush-- TW-axis 0deg DP3\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP3.jpg\" alt=\"\" width=\"359\" height=\"121\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP3.jpg 1117w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP3-300x101.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2013\/09\/RAAL-140-15D-1L-flush-vs-noflush-TW-axis-0deg-DP3-1024x345.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><\/p>\n<p><strong>Blue<\/strong> = No flush-mount<\/p>\n<p><strong>Red<\/strong> = Flush-mount<\/p>\n<p><strong>Upper Left:<\/strong> DPN<\/p>\n<p><strong>Upper Right:<\/strong> DP1<\/p>\n<p><strong>Lower Left:<\/strong> DP2<\/p>\n<p><strong>Lower Right:<\/strong> DP3<\/p>\n<p>The face-plate of the RAAL ribbon is only 2mm thick and flush-mounting it is more or less a cosmetically decision rather than technical. All my published measurements are made with the RAAL ribbon flush-mounted using a 2-3mm thick felt carpet covering the entire baffle.<\/p>\n<p><strong>What about distortion?<\/strong><\/p>\n<p>The distortion figures isn\u2019t up to the very best dome tweeter\u2019s performance e.g. ScanSpeak D3004\/664000 Beryllium tweeter, but for a ribbon tweeter still a respectable performance.<\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-90db-DP2.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2620\" title=\"140-15D-2R -- 15cm 90db DP2\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-90db-DP2.jpg\" alt=\"\" width=\"359\" height=\"206\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-90db-DP2.jpg 1234w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-90db-DP2-300x172.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-90db-DP2-1024x590.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-90db.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-1929\" title=\"D3004-664000-2R -- 10cm 90db\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-90db.jpg\" alt=\"\" width=\"359\" height=\"206\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-90db.jpg 1234w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-90db-300x172.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-90db-1024x590.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-95db-DP2.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-2627\" title=\"140-15D-2R -- 15cm 95db DP2\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-95db-DP2.jpg\" alt=\"\" width=\"359\" height=\"206\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-95db-DP2.jpg 1234w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-95db-DP2-300x172.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/09\/140-15D-2R-15cm-95db-DP2-1024x590.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><a href=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-95db.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-1933\" title=\"D3004-664000-2R -- 10cm 95db\" src=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-95db.jpg\" alt=\"\" width=\"359\" height=\"206\" srcset=\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-95db.jpg 1234w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-95db-300x172.jpg 300w, https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/05\/D3004-664000-2R-10cm-95db-1024x590.jpg 1024w\" sizes=\"auto, (max-width: 359px) 100vw, 359px\" \/><\/a><\/p>\n<p><strong>Upper left:<\/strong> RAAL 140-15D Ribbon tweeter (DP2) @ 1m 90dB<\/p>\n<p><strong>Upper right:<\/strong> ScanSpeak D3004\/664000 Beryllium tweeter @ 1m 90dB<\/p>\n<p><strong>Lower left:<\/strong> RAAL 140-15D Ribbon tweeter (DP2) @ 1m 95dB<\/p>\n<p><strong>Lower right:<\/strong> ScanSpeak D3004\/664000 Beryllium tweeter @ 1m 95dB<\/p>\n<p>As can be seen on the distortion charts the gap between them\u00a0narrows down with increasing SPL. Also the harmless second-order harmonics is actually lower for the ribbon. And obviously the dome tweeter can be crossed-over much lower without distortion issues.<\/p>\n<p>When using the supplied \u201cfoam deflection pads\u201d it actually helps lowering the distortion as well as controlling the vertical horizontal frequencies dispersion.<\/p>\n<p>Based on the distortion figures I would recommend as many other people have for the RAAL ribbon tweeter, a cross-over point of about 3kHz or higher. If the max SPL requirement isn\u2019t a concern or if you use steep filtering a 2-2.5kHz cross-over point could possibly work.<\/p>\n<p>With the <strong><span style=\"color: #666699;\">Sequence Three \u2013 Grand Reference<\/span><\/strong> loudspeaker design I\u2019m aiming for a cross-over point of around 3kHz, so it\u2019s seems to be working as I planned and expected. Further measurements and of course listening test will finally decide the exact cross-over point. With the AT mid-range and the RAAL ribbon I will have a possible cross-over range somewhere between 2.5-3.5kHz. Not a super wide range, but wide enough to make it work.<\/p>\n<p>To sum up, I think the RAAL 140-15D measurement performance lives up to my expectations and I\u2019m eager to continue with the <span style=\"color: #666699;\"><strong>Sequence Three \u2013 Grand Reference<\/strong><\/span> loudspeaker design. Next up is to publish the results from the AudioTechnology mid-range measurements.<\/p>\n<p>For further detailed measurements see: <a href=\"https:\/\/www.audioexcite.com\/?page_id=2523\">RAAL 140-15D Measurements<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>RAAL 140-15D Measurements! I\u2019ve made some extensive measurements on the RAAL 140-15D ribbon tweeter and before the measurements I installed brand new replacement ribbons in both the RAAL tweeter samples and tightened up the ribbons as in this instruction video from RAAL. As instructed, it worked perfectly. \ud83d\ude42 Since it\u2019s possible to shape the frequency [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-2640","post","type-post","status-publish","format-standard","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/2640","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2640"}],"version-history":[{"count":35,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/2640\/revisions"}],"predecessor-version":[{"id":7086,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/2640\/revisions\/7086"}],"wp:attachment":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2640"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2640"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2640"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}