Coral fullrange speakers 12"

[cypher]

Hi There,
I'm looking for any information about this speakers, especially TS parameters.
Perhaps someone is able to recognize them form attached pictures?
Many thanks,
Regards,
Arthur

[cypher]

Some more pict

[cypher]

And the last one..

[GM]

Greets!

These appear to be the same inexpensive ones sold under the LaFayette and Olson brands here in the USA decades ago. If so, I don't have T/S specs, but according to my notes I wound up with a 60" high x 23.875" W x 14.75" D bottom exit TL that I fine tuned in-room by varying its gap to the floor. Driver was 24.875" down from the top. All dimensions are inside (i.d.).

From this we see can conclude that between the small magnet and my 12+ ft^3 cab that it has a high Qts, so today most DIYers would probably prefer a 3 - 4 ft wide OB if they have the room.

GM

[rjbond3rd]

Hi GM, so did the floor-firing exit constitute a "port" somehow? Would it have been an MLTL? This height-adjustable bass response sounds like a unique design that would have some nice properties.

[Scottmoose]

Unless I'm reading it incorrectly, the cab will have been open at the base, & simply height adjustable to provide a form of slot loading that could be adjusted to tailor things to the room.

[GM]

Greets!

Right, you're creating a slotted vent. The 60" pipe by itself is good for low 50s tuning and mass loading brings it down into the 30s, which was all that was needed for 99.9% of all the available vinyl and tapes back then.

It's hardly unique though, it was used extensively to extend the early Radiola, etc., mock furniture horns. Not much genuinely new in speaker design and was revived in the late '50s when two channel stereo was being promoted.

Some consoles would have a single, centrally located wide BW DVC 'woofer' firing out the rear through a slot (4th order band-pass) which in turn could be fine tuned by varying the distance to the room's wall. Combined with small 'FR' drivers for the L/R channels at the outside front, or in some cases, on the side panels with adjustable hinged door panel reflectors to somewhat mimic a poor man's JBL Paragon, a complete, pretty decent stereo could be had in a nice looking, though large, piece of furniture.

GM

[Scottmoose]

Interesting. Thanks (as always ) for the background. Just been looking at some of that Radiola gear. Pretty -I can just imagine Ivor Novello numbers being played through some of those things.

Never had chance to hear a Paragon, more's the pity. Here's hoping that one day... I still find it astonishing that they never had any proper plans for the thing, & that the DIY ones have vanished into the ether. Reminds me of some old English coach builders like Mulliners (a criminal loss) where it was almost entirely in the hands of the artisans.

[GM]

You're welcome!

I've had very little exposure to the early radios and players beyond pictures, patents and as props in movies and while their sound quality was marginal at best, their technical ingenuity is for the most part extremely impressive and of course being a rich man's toy their craftsmanship was second to none for the times.

Frankly, I was seriously underwhelmed with the Paragon's performance, but what a joy to look at! The Hartsfield OTOH, beauty and 'brains'!

Hmm, IIRC someone (I thought JBL) at one time sold complete construction prints. For sure I've seen what appeared to be factory type construction drawings, but had no interest in building one, so made no attempt to get a copy. I imagine you could get one from somebody over on the JBL Heritage forum if you ask real nice, but getting the proper horns would probably be a time consuming DIY affair.

Yeah, try finding factory body template drawings to build the wood bucks for a 1950 Ferrari Barchetta. FoMoCo OTOH could at least into the late '70s provide you with tool and die drawings for a '29 FORD body and frame to use as a dimensional guide to scratch build one. The difference between hand crafted and mass production.

GM

[blumenco]

I bought a ton of those stereo console thingeys from thrift stores during college. fixed em up (the ones that were worth playing with), and gave or sold them to friends so they could have a "classy" system tho thrash their Ipods through while simultaneously having a place to spill their keg cups.

Some of those things sounded pretty darned good too. It definitely still makes me reevaluate whether or not we really need separate "stereo" speakers for simply enjoyable music.

Some were OB, some were floor loaded TL like you described.

A driver like shown above is par for the course (maybe a bit above). Nice sounding, likely. Play with it!