Is the horn a piezo?
If so it may not have any XO components at all
A 5uF capacitor implies that the ovoid driver is doing all the midrange
That looks very likely. Perhaps jmhitchcock will tell us if it has a magnet or not. I'm still puzzling over the wiring in the photo though!
I’ll go out to the garage and take some pics of the horn and crossover wiring once the kids go to bed.
The QUEST for Musical Magic ...
Three generations of MEN in your family could bond-together building diyAudio Musical Magic speakers.
Quest 1: an 18" wide Klone of the Tweek Geeks BMF-1. $650/speaker in parts, Bi-Amp or DSP tri-amp.
Quest 2: 28" wide Big Easy uses new tech coaxial compression driver +18" woof $900/speaker in parts. Bi-Amp w/DSP option.
MANY-MINDs: Open Source "Tower XL"
The Meaning of Life is Family ....
commit your MEN to the QUEST for Musical Magic from diyAudio
PS. a network fault printed "sex toys" but omitted " like medical teaching tools 'invisible man' and 'invisible woman"
Three generations of MEN in your family could bond-together building diyAudio Musical Magic speakers.
Quest 1: an 18" wide Klone of the Tweek Geeks BMF-1. $650/speaker in parts, Bi-Amp or DSP tri-amp.
Quest 2: 28" wide Big Easy uses new tech coaxial compression driver +18" woof $900/speaker in parts. Bi-Amp w/DSP option.
MANY-MINDs: Open Source "Tower XL"
The Meaning of Life is Family ....
commit your MEN to the QUEST for Musical Magic from diyAudio
PS. a network fault printed "sex toys" but omitted " like medical teaching tools 'invisible man' and 'invisible woman"
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Pardon my rather crude drawing of the wiring. Let me know if it helps or doesn’t make any sense at all. I also added a pic of the horns.
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That small, closed-back tweeter that Zenith used, likely has a 30 to 40 ohm voice coil - I've come across them in doing console work at the shop.
Zenith had some odd setups through the years, I never could figure out some of it.
But I suppose it's to justify their marketing/advertising, - the more speakers, the better.
Yes wiseoldtech, it can be seen in the photo that it is a Foster 49-1094 45 ohm tweeter.
It is definitely wired in parallel with the 'woofer' and that is what had me puzzled.
Is it because of its high impedance that it is not overloaded by the bass frequencies?
I've seen similar tweeters which carry a third terminal from which a 2uF capacitor connects to the voice coil terminal in order to supply the high pass filter as shown in the attached image of the Zenith radio..
Here's a link to the refurbishment of a similar Zenith console. Note the carbon resistor which is incorporated in its crossover!
Repurposing a 70s console -
Techtalk Speaker Building, Audio, Video Discussion Forum
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Looking back at the goals stated in your first post, maybe trying to save those old and odd Zenith speakers is going to be an exercise in diminishing returns. It sounds like you’re not interested in a “full-on down to the studs restoration.” It seems to me that you have a piece of furniture that holds happy memories for your wife and also happens to make music. With a modern amp and streaming music, it’s never going to sound like it did back in the day, and I doubt you would want it to.
Why not pull out all the electronics, including the speakers and crossovers, and find someone who can use them as spare parts for a real restoration? Then, install the new amp (stereo or 2.1 if you want a subwoofer), install your chromecast device. That install could be as easy as cutting and staining a new floor for the well under the lid and just setting them inside. Then replace the speakers with some decent automotive 2-way 6x9s. If your plan includes a subwoofer, it would likely sound just fine installed in the center floor of the console... or get a car subwoofer box and screw it down in the same space.
The console will look like it did in your wife’s memory, but sound more like 21st century ears expect music to sound.
Why not pull out all the electronics, including the speakers and crossovers, and find someone who can use them as spare parts for a real restoration? Then, install the new amp (stereo or 2.1 if you want a subwoofer), install your chromecast device. That install could be as easy as cutting and staining a new floor for the well under the lid and just setting them inside. Then replace the speakers with some decent automotive 2-way 6x9s. If your plan includes a subwoofer, it would likely sound just fine installed in the center floor of the console... or get a car subwoofer box and screw it down in the same space.
The console will look like it did in your wife’s memory, but sound more like 21st century ears expect music to sound.
Could it be the only reasons those 45 ohm drivers are there is to bring the total impedance up and to allow the marketing department to use the phrase “4 way speakers?”
Please measure DC resistance across small cone terminals, with nothing else attached to them, and post it here.
I suspect it will read "open" , which then might indicate some small series capacitor inside the closed back bell, between it and the actual cone.
Usually those are "outside" as mentioned above, but inside placement is not impossible.
FWIW large Piezo drivers often include a complex crossover and protection system inside the back plastic envelope, besides the plain piezo element.
I suspect it will read "open" , which then might indicate some small series capacitor inside the closed back bell, between it and the actual cone.
Usually those are "outside" as mentioned above, but inside placement is not impossible.
FWIW large Piezo drivers often include a complex crossover and protection system inside the back plastic envelope, besides the plain piezo element.
Those Zenith 49-1094 "tweeters" are just a 45 ohm speakers with a stiff cone, thus favoring treble response. - no need for any crossover caps.
Since they're of such a high ohms, they present little to no load on the whole system.
They put out a weak sound, but as I mentioned before, allows marketing to add an extra speaker in advertising.
Absolutely! We decided to stick with the current speakers for now. I ordered new caps for the crossover, removed the speakers and started stripping the finish.
This week my goals are:
1) finish stripping the old finish
2) build the storage compartment where the old amp and turntable were
3) prep the cabinet for the new stain
4) Decide on the amp we will use (Leaning towards a sonos amp my friend will sell cheap if I want it)
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Cool! Thanks for the inspiration. I have been infected with my wife’s obsession with reviving and repurposing “Mid-century Modern” stuff.
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