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Pre-war Radio features Bose-Wave type Speaker!
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Return to top of page · Post #: 1 · Written at 7:07:11 PM on 7 November 2019.
	NewVista Location: Silver City WI, US Member since 10 May 2013 Member #: 1340 Postcount: 977
Saw this unusual pre-war radio off in a corner at Habitat-for-Humanity charity store: As a "luxury-feature", it has a complex bass system - forerunner of BOSE 'Wave' principle!

Return to top of page · Post #: 2 · Written at 8:30:58 PM on 7 November 2019.
	Brad Administrator Location: Naremburn, NSW Member since 15 November 2005 Member #: 1 Postcount: 7301
Photo uploaded. ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ A valve a day keeps the transistor away...

Return to top of page · Post #: 3 · Written at 9:21:06 PM on 7 November 2019.
	GTC Location: Sydney, NSW Member since 28 January 2011 Member #: 823 Postcount: 6687
So ... did you grab it?

Return to top of page · Post #: 4 · Written at 10:07:24 AM on 8 November 2019.
	Irext Location: Werribee South, VIC Member since 30 September 2016 Member #: 1981 Postcount: 470
A primitive transmission line!!

Return to top of page · Post #: 5 · Written at 11:07:45 AM on 8 November 2019.
	MonochromeTV Location: Melbourne, VIC Member since 20 September 2011 Member #: 1009 Postcount: 1182
The "Acoustical Labyrinth" was also a feature on some Australian made Stromberg Carlson console radio's built from 1936/7 onwards. https://trove.nla.gov.au/newspaper/article/77936745/7669862

Return to top of page · Post #: 6 · Written at 12:11:33 PM on 8 November 2019.
	NewVista Location: Silver City WI, US Member since 10 May 2013 Member #: 1340 Postcount: 977
".. did you grab it?" I left it there as that store has been getting somewhat savvy on pricing, having $85 on sticker, but now $68 and, by policy, reducing by 20% every month. Would still be worth it as its 6F6 P/P outputs are worth $50 each alone. Collectors visit there and have been taking note of this one, but no takers yet. Would like to hear its bass, but was turned off after noting that Labyrinth assembly is constructed out of a special taut type of double-walled corrugated 'cardboard' - whereas the picture on the back implies that it is constructed with thick wood (which would be required for successful operation IMO.) As expected, tapping the top of the labyrinth chamber made a boxy resonant "thump" - meaning a lot of the backwave bass would simply re-radiate through the 'cardboard' (with added distortion) before making it to the (1/4 or 1/8 wavelength?) channel exit, in my estimation.

Return to top of page · Post #: 7 · Written at 12:25:41 PM on 8 November 2019.
	NewVista Location: Silver City WI, US Member since 10 May 2013 Member #: 1340 Postcount: 977
https://trove.nla.gov.au/newspaper/article/77936745/7669862 This is interesting, a good find! Would like to see how they did the earlier 1936 version.

Return to top of page · Post #: 8 · Written at 1:49:04 PM on 8 November 2019.
	Fred Lever Location: Toongabbie, NSW Member since 19 November 2015 Member #: 1828 Postcount: 1250
Hi NV, yeah its a folded horn to get some feet length into the back wave. That would give it phase displacement but more than that a "second source" radiator outlet at low frequencies. Also agree the thing would want to be solid and well damped wood, otherwise it will just be a radiator/absorber not a pipe! Having made a few bass boxes with folds I can see the short comings, but maybe better than nothing. In a era of open back consoles with nil bass response ANYTHING that guided the back wave would be better and probably sound amazing in comparison. Fred.

Return to top of page · Post #: 9 · Written at 6:04:29 PM on 8 November 2019.
	NewVista Location: Silver City WI, US Member since 10 May 2013 Member #: 1340 Postcount: 977
This is cool: Tech (in Canada?) takes one of these apart and also discovers (at 3 minute mark) "oops, it's made out of cardboard!" https://www.youtube.com/watch?v=mViuN3zGePk

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