Eames Quadreflex

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old thread, old speakers, retro = hip !

Hi There !


I'd like to dig up this old thread, as I got permission to build a pair for our living room (waf ;) )

Is there anyone who knows more of these cabs ?
maybe drawings or detailed pictures ?

Or would it be best to design something new that would look like the outer form ?


Cheers,

Empee
 
Modern designs take into account all the errors made in the past .
I see now the drivers are better off the median axis of the cabinets , as a non centered-in-the-very-middle of the baffle gives an opportunity to early reflections from the baffle to be spread not uniformly due to the varying distance of the driver from the boards .
Also ,in that design which may remind a sort of 'Onken' for the bass load , the baffle is quite un-existent ...:eek:
 
Hi Pico,


Thanks for your comment!

I fully agree about the errors of the past.
Still, there are numerous speakerbuilders who still use centrered speakers and
razorsharp cabinet edges :cubist:

And really, even with these shortcommings, some speakers really sound very, very good.


But the question about the Quadraflex remains:

is it a bass reflex ?
is it a horn ?
is it some sort of aperiodic box ?
or maybe even a closed box inside a nice looking shell ?


Who is to enter a museum armed with some screwdrivers and measuring tape ? :D


:drink:
Empee
 
Goodmorning !


Wow,
The Frazier look like a good starting point !

Just add a front facing driver to make the whole fullrange ?


Hey; I just described the RCA twinpower.....
:D
 

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These Eames enclosures look to me to be a big vent reflex with the vent/horn
on all four sides of the driver instead of above and below as done by scottmoose
and Planet 10. I guess that the speaker mounting baffle should have rounded or
tapered edges and I'm sure you could model it as a big vent in Horn Response.

On a smaller scale it might be an answer to my own question in the full range
thread.
jamikl
 
For me the major issue of that design is at a pure physical matter< the driver has an halo of emission around that somehow interferes with the quasi-:confused: spherical point source represented by the woofer> and may end in confused sound....

Well, when the driver's acoustic radiating plane is recessed somewhat relative to the vent's, it imparts a mild BP loading that if properly designed will act as an acoustic XO between the front, rear radiation to minimize comb filtering. This does require a stepped up HF response to keep it nominally flat out to a high system cut-off though.

GM
 
But speaking of wich;
isn't an Onken basically a Big Vent Reflex ?

another option;
an aperiodic cabinet inside an outer-shell wich is there just for looks ?

Sure, with the right driver specs.

Right, I coined the BVR phrase to describe a large expanding vent system such as the Quadraflex's, so it would apply to the Onken also, though not the RCA which is a folded up front and back loaded horn. Indeed, the Jensen Ultraflex/Onken were based on Thuras's original BVR patent test boxes.

There's been much mystique/misunderstanding about these cabs, but in an interview decades later, Thuras said that he only made such a large cab with a Sd = Av vent system to keep the patent's math simple. The sample driver was actually put in production in a much smaller ~8 ft^3 cab tuned with a Av = 1/4 Sd reflex vent to tune it to Fs.

GM
 
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