Stromberg Carlson 435-M Labyrinth
 

When it rains it pours, especially with local CL ads for antique radios.

This model is not pictured in Radioatticarchives, so I figure it may be less common. The amplifier is PP 6V6 tubes, similar to GE sets of 1940.
It has both AM and SW with preset pushbuttons on one chassis plus a second
chassis for the pre-1948 FM band that is 42-50 Mc
The real interesting part is the cardboard tuned ports for the speaker.
This claims, in an advertisement, to block all unwanted sounds from coming out the front.
Also got a nice Philco 37-9 and a chassis from a Majestic 92 (which is a Grigsby Grunow 90B)

https://farm1.staticflickr.com/334/2...0b1ddc08_z.jpg
https://farm1.staticflickr.com/503/2...4b957c65_z.jpg

You'll find the Stromberg Service data on my website: http://audiophool.com/MadeInRoch.html

Cardboard labyrinth
 

The labyrinth concept is OK and very interesting for a radio of that era. It should have been a "selling point".
But cardboard and any easily-vibrating material is bad for anything acoustic. It colours the sound by absorbing some frequencies and reinforcing others, and thus the frequency response has peaks at the fundamentals and harmonics of every piece of vibrating surface in the speaker enclosure.
That said, I wolud not be very surprised if the set had a very pleasant sound. Acoustics is a very subjective subject. And the theories on the physics books work much better in the books than in the real life.
Good luck with your new-old radio!!

Some Bose radios use labyrinths made of plastic. The same plastic piece that forms the cabinet. May or may not be "hifi"...

Labyrinths were used in a lot of medium-level equipment with smaller-than ideal speaker enclosures, to try and make them give a better bass.

But it was a surprise to me seeing one in a vintage radio. Maybe I am not so old, after all. :D

Soviet-made Elektronika stereo record players of the ´80 vintage had plastic labyrinths inside the speaker enclosures. I saw one once and the labyrinth was not even fixed to the cabinet. Nice noises it made.

The one I saw was junk, so maybe it came from the factory correctly fixed to the enclosure, and later someone opened the enclosure, unscrewed the labyrinth and ended with some "extra" screws.

That's similar to my 440-M, which also had the acoustical labyrinth. You can read about that radio, with a link to the labyrinth patent, in this article:

http://antiqueradio.org/StrombergCarlson440M.htm

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

http://antiqueradio.org/art/Stromber...n440MFront.jpg

Most of those sets came through with the wide radio-phono cabinet, much less desirable.