{"id":32,"date":"2010-10-03T14:11:19","date_gmt":"2010-10-03T13:11:19","guid":{"rendered":"http:\/\/storycase.co.uk\/radio\/?p=32"},"modified":"2018-06-09T22:14:05","modified_gmt":"2018-06-09T22:14:05","slug":"the-beolit-speaker-problem","status":"publish","type":"post","link":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/","title":{"rendered":"The Beolit Speaker Problem"},"content":{"rendered":"

\"\"Bang and Olufsen’s iconic range of transistor radios designed by Jacob Jensen and hugely popular in the seventies had one or two faults that could develop over time. As the Beolit was designed so well many have survived but\u00a0some suffer from poor sound reproduction.<\/p>\n

Warning – this gets technical and requires some technical knowledge and equipment.<\/p><\/blockquote>\n

When working correctly the sound quality is\u00a0excellent for a battery powered transistor radio due mainly to the large elliptical loudspeaker and transformer-less audio output design. The audio amplifier uses a complimentary pair of germanium transistors that tend to sound warmer than silicon devices that replaced them. Germanium was the first semi-conductor\u00a0used to manufacture transistors but suffered from a run-away characteristic when they overheat and burn out. Output stages had to incorporate thermistors or other devices to detect the increase in temperature and shut down the output transistors to stop the self destruction.<\/p>\n

Over time the speaker cone becomes stiff and can’t move freely leading to a ‘tinny’ weak sound. The voice coil seems to stick – pulled in towards the magnet. It is possible to apply a controlled low DC voltage to the coil which allows the coil to heat up and pull itself out providing you get the voltage polarity to push in the right direction. Positive to the plus terminal on the speaker pushes the cone out on a working speaker. If you have a faulty speaker it’s worth trying this technique but it comes with a caveat that I take no responsibility for the outcome! It need just the right amount of heat to loosen the coil but not too much that melts the coil former. I tried about 15 seconds at 1-2 amps and then applied a low frequency – around 50Hz so the vibration helped it free.<\/p>\n

A combination of DC volts and 50-100Hz sine wave is best using two 1000\u00b5F capacitors in series to stop the voltage from damaging the output stage. You can use the radio’s amplifier but check the coupling capacitor has not gone short circuit. The orange and grey plastic cylindrical capacitors are prone to fail in this way and I suspect one reason why the speaker gets stuck in the first place.<\/p>\n

If you have no luck freeing the speaker coil finding a replacement speaker is the next step. The 7×5 inch SEAS unit fitted is less than 50mm deep with a 60mm diameter magnet and most 4\u03a9 speakers have larger deeper magnets. There was a replacement made by Vifa, another Danish company part number S18\/12FD-1 but one I have was\u00a0manufactured back in 1983 so difficult to find. A similar unit was also used in some thin line B&O speakers as a mid range driver.<\/p>\n

One option is to fit a 6×4 inch speaker on a plate cut to the original 7×5 inch outline. This allows a wider choice of a more standard size speaker but the bass response may not be quite as good as the original. Visatron make a 9 x 15cm unit FR 9.15 that fits and sounds remarkably good for the size.<\/p>\n

I’ve seen some Beolits with a replacement speaker glued onto the front panel – a drastic step but the only option if you can’t find a slimline replacement. Don’t do this at home \ud83d\ude42 Less authentic choices are 4-5 inch round speakers but again many better performance drivers have large magnets intended for in-car mounting and too large for the Beolit.<\/p>\n

Grundig fitted good quality elliptical speakers to their seventies transistor radios such as the Yacht Boy or Concert Boy ranges. However the depth of these exceed 50mm and are only 7×4.3 inch so don’t fit.<\/p>\n

Hope this helps improve the sound of your Beolit.<\/p>\n","protected":false},"excerpt":{"rendered":"

Bang and Olufsen’s iconic range of transistor radios designed by Jacob Jensen and hugely popular in the seventies had one or two faults that could develop over time. As the Beolit was designed so well many have survived but\u00a0some suffer… Continue Reading →<\/a><\/p>\n","protected":false},"author":1,"featured_media":29,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,18],"tags":[7],"class_list":["post-32","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-beolit","category-restoration","tag-problem"],"yoast_head":"\nThe Beolit Speaker Problem - Radio Retro<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The Beolit Speaker Problem - Radio Retro\" \/>\n<meta property=\"og:description\" content=\"Bang and Olufsen’s iconic range of transistor radios designed by Jacob Jensen and hugely popular in the seventies had one or two faults that could develop over time. As the Beolit was designed so well many have survived but\u00a0some suffer... Continue Reading →\" \/>\n<meta property=\"og:url\" content=\"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/\" \/>\n<meta property=\"og:site_name\" content=\"Radio Retro\" \/>\n<meta property=\"article:published_time\" content=\"2010-10-03T13:11:19+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2018-06-09T22:14:05+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"2592\" \/>\n\t<meta property=\"og:image:height\" content=\"1944\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"rick\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rick\" \/>\n\t<meta name=\"twitter:label2\" content=\"Estimated reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/\"},\"author\":{\"name\":\"rick\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#\\\/schema\\\/person\\\/09a8b498e2b63805f59451dd22c11801\"},\"headline\":\"The Beolit Speaker Problem\",\"datePublished\":\"2010-10-03T13:11:19+00:00\",\"dateModified\":\"2018-06-09T22:14:05+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/\"},\"wordCount\":631,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2010\\\/10\\\/SSL10892.jpg\",\"keywords\":[\"Problem\"],\"articleSection\":[\"Beolit\",\"Restoration\"],\"inLanguage\":\"en-GB\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/\",\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/\",\"name\":\"The Beolit Speaker Problem - Radio Retro\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2010\\\/10\\\/SSL10892.jpg\",\"datePublished\":\"2010-10-03T13:11:19+00:00\",\"dateModified\":\"2018-06-09T22:14:05+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#breadcrumb\"},\"inLanguage\":\"en-GB\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-GB\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#primaryimage\",\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2010\\\/10\\\/SSL10892.jpg\",\"contentUrl\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2010\\\/10\\\/SSL10892.jpg\",\"width\":\"2592\",\"height\":\"1944\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/beolit\\\/the-beolit-speaker-problem\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"The Beolit Speaker Problem\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#website\",\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/\",\"name\":\"Radio Retro\",\"description\":\"Don't throw it away!\",\"publisher\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-GB\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#organization\",\"name\":\"Radio Retro\",\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-GB\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2014\\\/11\\\/IMG_0324.jpg\",\"contentUrl\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/wp-content\\\/uploads\\\/2014\\\/11\\\/IMG_0324.jpg\",\"width\":1200,\"height\":800,\"caption\":\"Radio Retro\"},\"image\":{\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#\\\/schema\\\/logo\\\/image\\\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/#\\\/schema\\\/person\\\/09a8b498e2b63805f59451dd22c11801\",\"name\":\"rick\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-GB\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g\",\"caption\":\"rick\"},\"url\":\"https:\\\/\\\/storycase.co.uk\\\/radio\\\/author\\\/rick\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"The Beolit Speaker Problem - Radio Retro","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/","og_locale":"en_GB","og_type":"article","og_title":"The Beolit Speaker Problem - Radio Retro","og_description":"Bang and Olufsen’s iconic range of transistor radios designed by Jacob Jensen and hugely popular in the seventies had one or two faults that could develop over time. As the Beolit was designed so well many have survived but\u00a0some suffer... Continue Reading →","og_url":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/","og_site_name":"Radio Retro","article_published_time":"2010-10-03T13:11:19+00:00","article_modified_time":"2018-06-09T22:14:05+00:00","og_image":[{"width":2592,"height":1944,"url":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg","type":"image\/jpeg"}],"author":"rick","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rick","Estimated reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#article","isPartOf":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/"},"author":{"name":"rick","@id":"https:\/\/storycase.co.uk\/radio\/#\/schema\/person\/09a8b498e2b63805f59451dd22c11801"},"headline":"The Beolit Speaker Problem","datePublished":"2010-10-03T13:11:19+00:00","dateModified":"2018-06-09T22:14:05+00:00","mainEntityOfPage":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/"},"wordCount":631,"commentCount":0,"publisher":{"@id":"https:\/\/storycase.co.uk\/radio\/#organization"},"image":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#primaryimage"},"thumbnailUrl":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg","keywords":["Problem"],"articleSection":["Beolit","Restoration"],"inLanguage":"en-GB","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/","url":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/","name":"The Beolit Speaker Problem - Radio Retro","isPartOf":{"@id":"https:\/\/storycase.co.uk\/radio\/#website"},"primaryImageOfPage":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#primaryimage"},"image":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#primaryimage"},"thumbnailUrl":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg","datePublished":"2010-10-03T13:11:19+00:00","dateModified":"2018-06-09T22:14:05+00:00","breadcrumb":{"@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#breadcrumb"},"inLanguage":"en-GB","potentialAction":[{"@type":"ReadAction","target":["https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/"]}]},{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#primaryimage","url":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg","contentUrl":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2010\/10\/SSL10892.jpg","width":"2592","height":"1944"},{"@type":"BreadcrumbList","@id":"https:\/\/storycase.co.uk\/radio\/beolit\/the-beolit-speaker-problem\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/storycase.co.uk\/radio\/"},{"@type":"ListItem","position":2,"name":"The Beolit Speaker Problem"}]},{"@type":"WebSite","@id":"https:\/\/storycase.co.uk\/radio\/#website","url":"https:\/\/storycase.co.uk\/radio\/","name":"Radio Retro","description":"Don't throw it away!","publisher":{"@id":"https:\/\/storycase.co.uk\/radio\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/storycase.co.uk\/radio\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-GB"},{"@type":"Organization","@id":"https:\/\/storycase.co.uk\/radio\/#organization","name":"Radio Retro","url":"https:\/\/storycase.co.uk\/radio\/","logo":{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/storycase.co.uk\/radio\/#\/schema\/logo\/image\/","url":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2014\/11\/IMG_0324.jpg","contentUrl":"https:\/\/storycase.co.uk\/radio\/wp-content\/uploads\/2014\/11\/IMG_0324.jpg","width":1200,"height":800,"caption":"Radio Retro"},"image":{"@id":"https:\/\/storycase.co.uk\/radio\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/storycase.co.uk\/radio\/#\/schema\/person\/09a8b498e2b63805f59451dd22c11801","name":"rick","image":{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/secure.gravatar.com\/avatar\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/640152bc2d2bd02654bf49df900799eaf604cf9f55f97d09f71e3132d648d916?s=96&d=mm&r=g","caption":"rick"},"url":"https:\/\/storycase.co.uk\/radio\/author\/rick\/"}]}},"_links":{"self":[{"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/posts\/32","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/comments?post=32"}],"version-history":[{"count":10,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/posts\/32\/revisions"}],"predecessor-version":[{"id":626,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/posts\/32\/revisions\/626"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/media\/29"}],"wp:attachment":[{"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/media?parent=32"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/categories?post=32"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/storycase.co.uk\/radio\/wp-json\/wp\/v2\/tags?post=32"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}