{"id":1481,"date":"2015-07-18T11:26:48","date_gmt":"2015-07-18T11:26:48","guid":{"rendered":"http:\/\/2016.carlssonplanet.com\/en\/speakers\/the-pop-box\/"},"modified":"2015-10-09T13:39:39","modified_gmt":"2015-10-09T11:39:39","slug":"the-pop-box","status":"publish","type":"page","link":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/","title":{"rendered":"The Pop Box"},"content":{"rendered":"

\"Click<\/a>
\nMore pictures of the Pop Box<\/a><\/p>\n

HISTORY<\/strong>
\nIn 1964 designs and directions for construction of a speaker that would strike Sweden with amazement was presented. The origin was that the magazine \u201dRadio & Television” in 1962 presented a cheap and simple do-it-yoruself transformer-less tube amplifier with \u201dextraordinarily excellent measures\u201d. The amplifier was constructed by Jon Idestam-Almqvist and required good speakers. J I-A choosed after various experimentation a design based on patents of Stig Carlsson and on \u201dKolboxen\u201d. This at that point nameless speaker was presented i R&T 4\/64, this issue is said to be the most stolen copy of a magazine from libraries in swedish history. Click below to read this article.<\/p>\n

Original DIY discription from Swedish magazine Radio & Television<\/a><\/p>\n

The speaker – which soon was named \u201dPopboxen\u201d (Pop-box) was equipped as a\u00a0Sonab OA5 typ II<\/a> and designed as a slightly wider OA 5 Typ II on high legs, with openly mounted tweeters, a long time before OA 5 Typ 1 with it\u2019s enclosed tweeter was introduced! Popboxen also had a true bass-reflex tube and the tweeters were arranged around the cavity on top where the mid-bass elemant fired upwards. \u201dPopboxen\u201d was constructed in two versions: one equipped with high-ohm elements powered by the cheap valve-amplifier, and another with same impedances for the speaker elements as SONAB OA5, to be powered by standard amplifiers. The latter probably sold in thousands.<\/p>\n

LISTENING IMPRESSIONS<\/strong>
\nPowered by the valve amplifier R&T considered that this speaker sounded better than any other speaker available on the swedish market, no matter price. We have not had the opportunity to listen to the valve-powered high-ohm version. But when listening to restored and aupgraded \u201dPopboxen\u201d-speakers with standard OA5 speaker-elements one is struck by how almost inconceivably well this speaker sounds. Treble is far better than in the serial produced\u00a0Sonab OA5 Typ 1 and the bass has a much better resolution and is more airy even compared to Sonab OA5 Typ 2. Look what a bass-reflex tube can accomplish! In addition we got the impression of less resonances from the cabinet than from the serial produced version. But this, of course, is due to the actual DIY-builders competence and selection of matter.<\/p>\n

Considering how incredibly well and without strain a renovated pair of the large valve-powered SONAB OA6 still sounds today we believe that a pair of valve-powered and renovated \u201dPopboxen\u201d also still sounds splendid. This model in many parts correspond with OA6 with the same high-ohm midbass-element, same high-ohm tweeters, the same output transformer less amplifier-principle and the same valves, ECC83 input-valve and EL86 output-valve. It is almost only the 10-inch-basses that are missing.<\/p>\n

RESTORING & UPRADING<\/strong>
\nEasy concerning the version without amplifier. Service the bass-elements, if the edge-surrounds are chapped, try to seal them with ultrathin rice paper and visco-elastic glue. Measure the the resistance of the element. Compare RESTORING & UPGRADING<\/a>. Otherwise the bass-element has to be replaced by good second-hand or new elements. Production was discontinued in 1980 so the possibility to find new ones is drastically reduced. HiFiKit (www.hifikit.se) is considering to start to produce them again, we hope for that. Otherwise CarlssonPlanet sometimes can help with good second-hand elements. The tweeters usually works fine, but you are recommended to exchange them for new, compare RESTORING & UPGRADING<\/a>. If you not exchange them, as a matter of precaution first check the DC resisitance. It should measure about 7 or 13 ohms depending on the version of \u201dPopboxen\u201d. Check that the cabinet is air-tight, some cabinets can have cracks in the joints. Seal carefully with sealant that remains elastic. Feel free to brace the cabinet with extra braces – measure to half-millimetre exactness, cut thin braces and apply glue to the ends of the braces and press them into place in the middle of the cabinet\u2019s largest free areas. Pieces of thin car damping sheet applied in proper places is favourable. Preferably fit gold-plated terminals to the backside of the bottom of the cabinet. It is easy. Drill the holes from inside (first fold away the glass wool, use gloves), press in the terminals and tighten as hard as possible. Then preferably solder on a new solid wire. Unless for this, restoration is done according to RESTORING & UPGRADING<\/a><\/p>\n

\"Click<\/a><\/p>\n

TECHNICAL DATA<\/strong><\/h3>\n

As published in the magazine \u201cRADIO & TELEVISION\u201d, no. 4\/1964.<\/p>\n

There are two different designs to this speaker.
\nOne to be used in normal systems and one to be used with an Output Transformer Less tube amplifier to be used with 800 Ohms speakers. The OTL amplifier was a DIY project by Jonathan Idestam-Almqvist with very impressive data published earlier in the same magazine No. 9\/1962.<\/em><\/p>\n

Principle:<\/strong> Two way bass reflex. Omni directional, tuned to 45Hz
\nBox volume:<\/strong> 41 litres
\nMeasures W x H x D:<\/strong> 28 x 66 x 42 cm, including height of feet,
\nWeight:<\/strong> 10 Kg
\nSize and weight may vary some due to the individual builder\u2019s choice of design and material.
\nImpedance:<\/strong> Approx 7 Ohms alternately 800 Ohms
\nCrossover frequency:<\/strong> 2.500 Hz
\nFrequency response:<\/strong> 40-14.000 Hz, within 6 dB.
\nSpeakers 8 ohms version<\/strong>
\nMid-bass:<\/strong> 1 pc 22 cm, 8 ohms Philips 9710M.
\nTweeters:<\/strong> 4 pcs 5 cm, 8 ohms Peerless MT20HFC
\nSpeakers 800 ohms version<\/strong>
\nMid-bass:<\/strong> 1 pc 22 cm, 800 ohms Philips 9710AM.
\nTweeters:<\/strong> 4 pcs 5 cm, 16 ohms Peerless MT20HFC used together with a Perless transformer, 1000 ohms to 16 ohms, 10 Watts
\nThe tweeters are set around the 9710.<\/p>\n

Prices:<\/strong>
\nSecond hand: 150 up to 800 SEK.
\nRestored and upgraded with new tweeters (Peerless CT62) prices ranging up even up to 3.000 \u2013 4.000SEK.<\/p>\n

Bj\u00f6rn H\u00e5kansson – Translator<\/b><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

More pictures of the Pop Box HISTORY In 1964 designs and directions for construction of a speaker that would strike Sweden with amazement was presented. The origin was that the magazine \u201dRadio & Television” in 1962 presented a cheap and simple do-it-yoruself transformer-less tube amplifier with \u201dextraordinarily excellent measures\u201d. The amplifier was constructed by Jon […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":603,"menu_order":4,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-1481","page","type-page","status-publish","hentry"],"yoast_head":"\nThe Pop Box - CarlssonPlanet<\/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:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The Pop Box - CarlssonPlanet\" \/>\n<meta property=\"og:description\" content=\"More pictures of the Pop Box HISTORY In 1964 designs and directions for construction of a speaker that would strike Sweden with amazement was presented. The origin was that the magazine \u201dRadio & Television” in 1962 presented a cheap and simple do-it-yoruself transformer-less tube amplifier with \u201dextraordinarily excellent measures\u201d. The amplifier was constructed by Jon […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/\" \/>\n<meta property=\"og:site_name\" content=\"CarlssonPlanet\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/carlssonplanet\" \/>\n<meta property=\"article:modified_time\" content=\"2015-10-09T11:39:39+00:00\" \/>\n<meta property=\"og:image\" content=\"http:\/\/old.carlssonplanet.com\/forum\/gallery\/image.php?mode=medium&image_id=423\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:site\" content=\"@AlltomCarlsson\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/\",\"url\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/\",\"name\":\"The Pop Box - CarlssonPlanet\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/#primaryimage\"},\"thumbnailUrl\":\"http:\\\/\\\/old.carlssonplanet.com\\\/forum\\\/gallery\\\/image.php?mode=medium&image_id=423\",\"datePublished\":\"2015-07-18T11:26:48+00:00\",\"dateModified\":\"2015-10-09T11:39:39+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/#primaryimage\",\"url\":\"http:\\\/\\\/old.carlssonplanet.com\\\/forum\\\/gallery\\\/image.php?mode=medium&image_id=423\",\"contentUrl\":\"http:\\\/\\\/old.carlssonplanet.com\\\/forum\\\/gallery\\\/image.php?mode=medium&image_id=423\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/the-pop-box\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Hem\",\"item\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Speakers\",\"item\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Produced\",\"item\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/speakers\\\/produced\\\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"The Pop Box\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/#website\",\"url\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/\",\"name\":\"CarlssonPlanet\",\"description\":\"Everything about the Carlsson loudspeakers!\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/carlssonplanet.com\\\/en\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"The Pop Box - CarlssonPlanet","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:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/","og_locale":"en_US","og_type":"article","og_title":"The Pop Box - CarlssonPlanet","og_description":"More pictures of the Pop Box HISTORY In 1964 designs and directions for construction of a speaker that would strike Sweden with amazement was presented. The origin was that the magazine \u201dRadio & Television” in 1962 presented a cheap and simple do-it-yoruself transformer-less tube amplifier with \u201dextraordinarily excellent measures\u201d. The amplifier was constructed by Jon […]","og_url":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/","og_site_name":"CarlssonPlanet","article_publisher":"https:\/\/www.facebook.com\/carlssonplanet","article_modified_time":"2015-10-09T11:39:39+00:00","og_image":[{"url":"http:\/\/old.carlssonplanet.com\/forum\/gallery\/image.php?mode=medium&image_id=423","type":"","width":"","height":""}],"twitter_card":"summary_large_image","twitter_site":"@AlltomCarlsson","twitter_misc":{"Est. reading time":"5 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/","url":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/","name":"The Pop Box - CarlssonPlanet","isPartOf":{"@id":"https:\/\/carlssonplanet.com\/en\/#website"},"primaryImageOfPage":{"@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/#primaryimage"},"image":{"@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/#primaryimage"},"thumbnailUrl":"http:\/\/old.carlssonplanet.com\/forum\/gallery\/image.php?mode=medium&image_id=423","datePublished":"2015-07-18T11:26:48+00:00","dateModified":"2015-10-09T11:39:39+00:00","breadcrumb":{"@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/#primaryimage","url":"http:\/\/old.carlssonplanet.com\/forum\/gallery\/image.php?mode=medium&image_id=423","contentUrl":"http:\/\/old.carlssonplanet.com\/forum\/gallery\/image.php?mode=medium&image_id=423"},{"@type":"BreadcrumbList","@id":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/the-pop-box\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Hem","item":"https:\/\/carlssonplanet.com\/en\/"},{"@type":"ListItem","position":2,"name":"Speakers","item":"https:\/\/carlssonplanet.com\/en\/speakers\/"},{"@type":"ListItem","position":3,"name":"Produced","item":"https:\/\/carlssonplanet.com\/en\/speakers\/produced\/"},{"@type":"ListItem","position":4,"name":"The Pop Box"}]},{"@type":"WebSite","@id":"https:\/\/carlssonplanet.com\/en\/#website","url":"https:\/\/carlssonplanet.com\/en\/","name":"CarlssonPlanet","description":"Everything about the Carlsson loudspeakers!","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/carlssonplanet.com\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/pages\/1481","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/comments?post=1481"}],"version-history":[{"count":6,"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/pages\/1481\/revisions"}],"predecessor-version":[{"id":8082,"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/pages\/1481\/revisions\/8082"}],"up":[{"embeddable":true,"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/pages\/603"}],"wp:attachment":[{"href":"https:\/\/carlssonplanet.com\/en\/wp-json\/wp\/v2\/media?parent=1481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}