• Check out the Annual AK Secret Santa exchange Program, signup before November 23rd in the AK Charities & Christmas forum!

Open Baffle Epiphany!

Since my great experience with the Zeniths I've been viewing lots of vintage 12 inch alnico speakers on the auction site which came from tube powered consoles and organs. You can read about them on guitar forums as they're a popular choice for guitar tube amps ( probably the reason you see so many singles for sale rather than pairs ). Evidently there weren't that many companies making them so one can tell the manufacturer by a sequence of numbers: Jenson ( 220 ), CTS ( 137 ), Cleveland ( 433 ), ROLA ( 285 ), Heppner ( 575 ), and Oxford ( 465 ). According to one forum the ribbed cones usually mean it's a wide band speaker and hence desirable for use in OB speakers. Although these speakers are large they are very light weight and only require four mounting points. One thing to remember is these speakers will not take lots of power as they were designed to be driven by low power tube amps. I'd really like to try a pair from vintage organs as they may be built to higher specifications (?). Here's a pair labeled as Magnavox but built for Hammond organs. The highly regarded Hammond B3 organ which came out in the 1950's is still the standard used in jazz recordings.

898758920_tp.jpg
 
Last edited:
The Zeniths have arrived!! Gonna wire them up and make sure they play, then they go in the baffles.


I also have a new to me DAC (audio gd NFB-15 with all the mods) I purchased from a good fella here on AK arriving today, it's a good day for system upgrades.

GAME ON!!
 

Attachments

  • IMG_1989.JPG
    IMG_1989.JPG
    106.1 KB · Views: 21
All checked out. They are in the baffles and playing Spotify through a Nobsound TPA 3116. They needed a tweeter badly. the sound was a bit hollow. They sounded like a brand new speaker sounds. Thin, hollow, muffled etc. I wasn't too worried as I figured these haven't been played in who-knows-how-long. After about 20 minutes they started to warm up. The sound became full. It's probably too early to say anything, but they are already every bit as good as the Beta 12LTA and the RCA 10" alnicos I have.

They're just smooooooooooooooooth. lack of wizzer cone? about to fire up the 2a3 amp.
 
IMG_1990.JPG Here's a photo of them with an eminence compression driver pulling tweeter duty with a 1uf cap as the crossover. Pretty happy at the moment , but could use a bit more treble and will roll some various caps to find one I like best(don't think they're even loosened up yet though- I guess I'm one of those guys that believes in speaker break in).

Do these look the same to you guys with the other 49cz models? Little felt dust cap in the middle.
 
The ribs on mine extend all the way to the edge. There's no surround like you see with most speakers, it's all ribbed cone.

One thing for sure you'll never have to re-foam them as you can't. :D
 
jelly_bean said:
View attachment 953422 Here's a photo of them with an eminence compression driver pulling tweeter duty with a 1uf cap as the crossover. Pretty happy at the moment , but could use a bit more treble and will roll some various caps to find one I like best(don't think they're even loosened up yet though- I guess I'm one of those guys that believes in speaker break in).

Do these look the same to you guys with the other 49cz models? Little felt dust cap in the middle.
Click to expand...

Good job! You can dress those gaskets with flat black not gloss. I used a $3 trial jar from Home Depot ( Behr Beluga latex ) and a small brush.

I've never thought about break in for a used driver but I suppose with years of inactivity and with changes in temp and humidity during storage some would be required.
 
cipriano said:
The dust cap looks exactly like mine, but the surround appears to be different. Is the surround a different material than the ribbed paper cone?
Click to expand...
The surround around the dust cap is the same material as the outer gasket.

Let them play brown noise all night. They still sound great this morning, but they are not full range. They do not sound good without a tweeter. but with a tweeter, it falls into place. I'm thinking they are somehow quite a bit different than what you guys have.

Later model perhaps?
 
Last edited:
Maybe?

With the Zenith 49CZ802 drivers tweeters really aren't needed. Mr Glow-in-the-dark confirms this with his 49CZ852.

In my case tweeters add a bit of shimmer/sizzle on the top end but without them I don't feel I'm missing anything..
 
I run my 49CZ852s full range and the highs are excellent, but I'm an old fart and probably can't hear anything above 14 to 15K.
 
Been pretty happy with the zeniths. I do think they are slightly different than the other 49cz models with the smaller alnico magnets. They still need a tweeter for the tippy top stuff as the highs are not really there. But the midrange is absolutely incredible-some of the very best I've ever heard at any price. I could live happily with these for a long time... but since vintage alnico drivers are still fairly cheap, I'm also looking at a few other 12" and 8" models to see if they tickle my fancy too. :-)
 
You must log in or register to reply here.
Back
Top Bottom