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"Name that...speaker"

Discussion in 'Speakers' started by Steve Smiley, Nov 10, 2018.

  1. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Hello AKers, I picked up a little project that I could use your help with. My research suggests that the horns are an Oxford variety. I can't find anything on the 12" woofer. it seems like it might be a full range number. probably an inexpensive console number. I am doing a bit of a refurb on them to see what kind of sound I can get out of it. I built a X-over based off of the single 4uf capacitor that was on the horn. I used the technical resources on the PE website to get around about design and put resistors in it to tone down the horn a bit. I'm working to seal up the cabinet to see what that does for the base, if anything. The original box has this rectangle vent cut out of the bottom of the baffle. I have no idea if that is necessary but for starters I'll go with a sealed box.

    I get that this could be a real exercise in futility, but I'm learning a lot. In the end, my sister thinks the console is kind of cool looking and will look good in her cottage. I'm not overly optimistic that this is a diamond in the rough but here's to my audio education!
    IMG_6568.JPG IMG_6573.JPG IMG_6577.JPG IMG_6615.JPG IMG_6571.JPG
     
    Lavane likes this.

     

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  2. gguillot

    gguillot AK Subscriber Subscriber

    Messages:
    1,700
    Location:
    Indianapolis, IN
    That's an interesting console! Never seen a design like that before. Some folks will probably chime in on those drivers...

    Look like some good candidates for econowave setup.
     
  3. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Yes, I thought the design was interesting as well. The folks at the thrift store were very supportive of me taking the console apart in the middle of the store to see what was inside. It was a "half off" day so I picked it up for $12. They even helped me load it up in my truck :) The center lower section has a few different blanks to fill the space. One is a cut-a-way so you can put your electronics in that section and still have access. I picture a TT on the shelf of it...
     
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  4. garyush

    garyush New Member

    Messages:
    8
    Back in the early 70’s I had a Capehart stereo that had Oxford horn tweeters in speakers. They sounded ok but I was only 14-15 at the time so really didn’t know much until I heard a real stereo system.
     
  5. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    I found a slightly dated posting on a Canadian market site that had that identical driver arrangement in a stand-alone speaker, but with furniture style legs. Makes me wonder if this wasn't a standard set up for some large furniture manufacturer.
     
  6. bowtie427ss

    bowtie427ss arigato gozaimashita Subscriber

    Messages:
    17,102
    Location:
    Land of Milk & Honey Boo Boo
    With the paper hinge on the woofers they likely have a fairly low Qts hence the large rectangular ports.

    A sealed alignment is probably at the opposite end of the spectrum of where they want to be. But, it's easy enough to try. My advice would be to keep any mods reversible.
     

     

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  7. bowtie427ss

    bowtie427ss arigato gozaimashita Subscriber

    Messages:
    17,102
    Location:
    Land of Milk & Honey Boo Boo
    More likely the product of a "house brand" contracted thru a furniture manufacturer near them.

    The cabinets may even have been sold empty with a few different load options offered to pair with them.
     
  8. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Thank you Bowtie, for the advice. I will keep it reversible. All the parts are currently pretty flexible. I wondered if the rectangular port was going to be a critical piece to this puzzle. I gather if it isn't right sealed, I should know right away? If it is a "fail" would the solution be the same rectangular port, or would a port of some type be an option? Or am I putting way too much thought into this? It would not be the first time...
     
  9. Gazdatronik

    Gazdatronik Super Member

    Messages:
    1,365
    Location:
    Chattanooga TN via Chicago
    Those baskets on the woofers sure look like Oxfords, what with the raised ribs joining the magnet support.

    Otherwise I can't find the external spider design like that.
     
  10. CopperWizard

    CopperWizard Well-Known Member

    Messages:
    836
    Location:
    Eugene, OR
    Hmm. I thought the paper surround suggested higher Qts.
     
  11. RTally

    RTally Speaker addict Subscriber

    Messages:
    629
    Location:
    Knoxville, Tennessee
    The patent on the big driver is from 1963: https://patents.google.com/patent/US3074504A/

    The spider-like part in the middle of the cone is a damper to reduce cone excursion at resonance. See Figure 1, items 17 (damper diaphragm) and 19 (weight).

    [​IMG]
     

     

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  12. musichal

    musichal poet emeritus Subscriber

    Messages:
    11,261
    Location:
    Norman OK
    Is it just me, or do those hand-wound, zip-tied inductors indicate some later re-tuning by some audio nut like us?
     
  13. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Indeed, the inductors are courtesy of Jantzen. I pieced together a X-over with parts I had on hand. I originally listened to the drivers open-baffle style and noted that the horns were a little overpowering. I wanted to pad them with a resistor and learned how I needed to use one in parallel across the tweeter leads and one in-line to keep the impedance the same to use the 4uf original cap (you can see I replaced original electrolytic cap with a poly-pro, but same value). Now that we know what we know from the US patent info (thank you RTally, I looked up #8074504, good find with #3074504!) maybe the inductor on the woofer side is unnecessary. I tested the crossover, again, open-baffle, and it sounded better...but how much can you really tell with the baffle resting on your knees:dunno:

    Thank you all for your input, I'm really enjoying learning from you. And, nobody has told me to quit while I'm ahead, so I will forge on!
     
  14. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    And given the date on that patent, what would we guess as the vintage on these drivers? Mid 60's?
     
  15. RTally

    RTally Speaker addict Subscriber

    Messages:
    629
    Location:
    Knoxville, Tennessee
    Often, manufacturers start making and selling products after the patent application is filed (1961 in this case). Most definitely they were selling it by the time the patent issued in 1963, particularly since the patent app was filed by the manufacturer. These speakers are rare. I've never seen any info on them in AK. I would guess the vintage is early 60s.
     
  16. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Thanks RTally, that is pretty cool. I've been getting more and more into this. I have tons I'd like to learn. I understood about 15% of what the patent application communicated, but I wasn't totally lost. My daughter thinks I'm nuts. Even more so than my wife. My daughter said to me the other day, "Daddy, how many pairs of speakers do we need anyway?" I now my wife was chuckling under her breath (although she is very supportive of the escape it provides me). To counter that, my son asked me last week if we could "mod" a pair of speakers together. Music to my ears! He is 8 yrs. old. We have rescued a pair of Canton HC100 bookshelves from their plastic (?) boxes and built some small cabinets out of reclaimed wood from old Michigan State dorm bunks. he thought that was pretty cool.

    Thanks everybody!
     

     

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  17. Lavane

    Lavane AK Subscriber Subscriber

    Messages:
    7,398
    Location:
    northern cal.
    I would think the bass reflex slot at the bottom would help a bit with the low end. That is a pretty unique looking piece. A nice 10 to 20wpc receiver would probably be all you need to drive those speakers.
     
  18. borus

    borus Luthier tube guy Subscriber

    Messages:
    486
    Location:
    VA Beach
    Please try to mount those horns from the front they may not fit but should be smother sounding if you do.
     
  19. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    I certainly believe I can mount those horns from the front, I appreciate it Borus, especially given that I think I might end up making new baffles today anyway. Normally that might not be too much effort but these cabinets are not square top and bottom.

    Thank you Lavane, bowtie, et al, I won't be surprised then if end up with replacing the rectangular port on the baffle. If I end up with a vent on the baffle, I guess working really hard to seal them up becomes a little less necessary? I actually spent the previous few days repairing them so I can get a tight seal, including wood glue to fill up a few worm holes:)

    I will work hard to get them to a place where I can do some listening today, while I still have people's attention. I appreciate the help everyone, I need it!

    I'll embrace the exploration.
     
  20. Steve Smiley

    Steve Smiley New Member

    Messages:
    24
    Location:
    Mid Michigan
    Ok, the results are in, although it wasn't a blow out. The vent does help a bit with the bass. It has just a bit more presence but it doesn't extend very deep with either. The speakers have a pretty good soundstage. The horns are really pretty nice. I think the resistors were a good idea.

    So I will commit to the vent, and that direction will help me move forward with the project. Now the question is:

    Do I just put in an identical smallish rectangular port in each baffle, like the original?

    I could see two circular ports, either side of center (easy to do with a hole saw).

    Is there any way for my to figure out a port tube? I wouldn't know where to start to try and size and tune one?

    How about a "shelf vent" at the bottom of the cabinet, kind of like you might see in some subwoofer cabinets?

    I'm open to all suggestions, thank you community!

    It won't surprise you to hear that the woofer cone and paper surround are very stiff (and the spider probably is too). Now that might be good for the cone, but perhaps less-so for the surround. Go easy on me if this is way out there, but what about cutting away the old paper surround and attach a new foam surround to it? Anything to gain by freeing up that cone a little? I think I may remember reading in another thread (Optimus 7 topic) that there might be a way to soften a paper surround. Maybe I should look back on that one. That might be a lot better than permanently damaging this unique driver (by cutting out the original surround).

    By the way, these are actually sounding pretty good. They are showing promise. That, or I'm really exhausted...

    Thank you again for any feedback!

    Steve
     

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