Mystery 60'ish coaxial loudspeaker

[hd220]

I bought at a GW several weeks ago a pair of the speakers pictured below. Would have left them but for $7.50 pair, what the heck. They sound reasonable well, very efficient. Midrange is right in front, in your face. Reasonably well extended low and middle highs but not overly extended high end. As expected, little low end. I have several similarly sized bookshelf speakers that these are no match for in the low end.

Cabs are vinyl wrapped but overall in great shape considering what their age might be. No badge or markings that identify to me the make or model. Baffle/grill is one piece and will only come off from the inside. They measure 14"H x 9 1/2"W x 8 1/4"D. Very similar in dimensions to a recently purchased Szabo 525 pair, but the Szabo's blow it away.

Does any know what these speakers are. I'm guessing the co-axial driver is an old Philips Deforest but I could be wrong.

 

[hd220]

More pictures:

 

[tom1356]

Not a coaxial but a full-range driver with a whizzer cone to add some high frequencies.

 

[audiozaz]

Does not strike me as a Philips either. They usually have part# preceded by "AD".

I'm guessing this is an 8" driver?

az

 

[barredowl]

Yeah whizzer cone not a true coaxial.

 

[stickman]

Those drivers look better suited to use in a doctor's office PA/intercom system than for music listening. The lack of an EIA code on the driver likely indicates they came from the orient somewhere. Just by the looks I would have guessed Quam as the brand name of the driver, but real Quam units have EIA codes. Hmm...

 

[nick12345]

Looks like something from "The Shack"...

 

[hd220]

OK . . . so I've learned a few things. Not a Philips speaker (I should have known that having worked for Philips many years ago); not a co-axial but full range with whizzer. However, it is not 8" but a 10" driver. There is nothing to indicate it might have come from the "Rat Shack". Still looking to know who might have made them but will probably strike out on that part. Wasn't expecting much in the way of it's potential but hey, for seven and a half bucks for both, they will make a good patio set.

 

[mhardy6647]

Not from Radio Shack, but it looks like a US-made basket. If you have a pair, try 'em on JE Labs (Joseph Esmilla) open baffles with a low-powered vacuum tube (preferably single-ended) amplifier; they might surprise you.

 

[audiozaz]

They measure 14"H x 9 1/2"W x 8 1/4"D.

However, it is not 8" but a 10" driver.

Is the baffle Euclidian?

az

 

[mhardy6647]

Ask Redboy about non-Euclidian speaker basket geometries :-(
http://www.audiokarma.org/forums/showthread.php?t=359816

 

[audiozaz]

Ask Redboy about non-Euclidian speaker basket geometries :-(
http://www.audiokarma.org/forums/showthread.php?t=359816

Bad case of intersecting planes.

az

 

[mhardy6647]

Bad case of intersecting planes.

az

yeah, maybe those two woogers passed through LaGuardia on their way to Redboy's :-O

 

[audiozaz]

yeah, maybe those two woogers passed through LaGuardia on their way to Redboy's :-O

Or went for a cruise aboard the USS Eldridge.

az

 

[hd220]

Yup. I quess that what makes these speakers special, the mfr managed to squeeze a 10" driver in the space of a 9 1/2" cab width.

Sorry guys, my mistake. They are 8".

 

[audiozaz]

Yup. I quess that what makes these speakers special, the mfr managed to squeeze a 10" driver in the space of a 9 1/2" cab width.

Sorry guys, my mistake. They are 8".

S'allright! We got a few chuckles out of it, so it's all good!

If they have a high-ish Qts as I suspect, you could try to run them with the backs removed to see if bass performance is better. The 98¢ mod could also help that "unterminated" whizzer; it consists in putting a thing strip of foam between the whizzer edge and the cone.

az

 

[adpopulum]

The "DGxx" code might be a clue. I have come across many RSC speakers in Canada sporting a DWxx" code. Could be a variation on that code? BTW, RSC stands for Radio Speakers of Canada. They did make Canadian manufactured Jensen's

 

[hd220]

Will remove the backs and try that out.

Question, removing that backs, is that like creating a bass reflex ported speaker, the open back being the port? ie. from Wikipedia for "bass reflex": " . . . using the sound from the rear side of the diaphragm to increase the efficiency of the system at low frequencies . . . ", without the ability to tune the (open back) port.

. . .so, is there a possibility of making this a ported speaker eventually?

 

[audiozaz]

Will remove the backs and try that out.

Question, removing that backs, is that like creating a bass reflex ported speaker, the open back being the port? ie. from Wikipedia for "bass reflex": " . . . using the sound from the rear side of the diaphragm to increase the efficiency of the system at low frequencies . . . ", without the ability to tune the (open back) port.

. . .so, is there a possibility of making this a ported speaker eventually?

It would be more of an open-baffle. More accurately a U-frame if I'm not mistaken. They usually have a higher roll-off point than fully enclosed boxes, but if the speaker does have a high Qts, it might make for tighter, more accurate bass, in this case.

az