Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Cabinets-Speakers => Topic started by: russ on August 27, 2009, 11:07:26 am
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So, I dug out the old box to look at my original dead Jenson 12 in. speaker! Can anybody help me here? It looks for all the world like an old version of a P12N! Mine has red and silver screw caps for the wire leads!! The bell cover is plain, no sticker or names on the metal anywhere. A few numbers. I'm thinking of having this repaired. The diameter at the center of the cone, (voice coil) is 2 and 1/2 inches.
Russ.
{EDIT: threads merged -PRR}
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So, I dug out the old box to look at my original dead Jenson 12 in. speaker! Can anybody help me here? It looks for all the world like an old version of a P12N! Mine has red and silver screw caps for the wire leads!! The bell cover is plain, no sticker or names on the metal anywhere. A few numbers. I'm thinking of having this repaired. The diameter at the center of the cone, (voice coil) is 2 and 1/2 inches.
I wonder what it's worth. My amp guy said it wasn't working, but the magnet in under the bell is , well, magnetic....
The P12N at Mojo is over $200.00 8 ohm. My Bassman is 50 watt and so is the P12N.
russ
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what are the numbers?
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Along the metal outer back; 2207218 (orB); then: MI-120 C8512
On the back side of the cone; Stamped in white, 8012B 16wC6
The coil in under the magnet is orange color, magnet black; all look intact, cone too, very clean
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This is the message I rec'd back from an inquiry from a local rebuilder: ( I thought it was a C12N at this point)
"Russ
If there is No Sound coming out of the Woofer & Voice Coils are bad, There is nothing I can do but order a Replacement Jensen Woofer. I only use Manufacturers recone kits. No After Market kits & Jensen does not have Recone kits available, Only Replacement Woofers. There are other people out there that do recone with after market kits, We do not. You can bring in your Woofer & I can Sweep it & see if What ever is wrong with it is something I can repair, But as I said If the Voice Coils are bad all I'll be able to do is Order a Replacement Woofer. I do not stock Jensen Woofers. I think a Replacement Jensen C12N is about $112.00 + Freight ( $10 to $15 ) & Tax."
russ
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Along the metal outer back; 2207218 (orB); then: MI-120 C8512
Jensen Concert series, designed as aftermarket replacements. Qute close to a C12P (1.5" VC if I remember correctly). Well worth a recone.
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In the Amp Tweaks and repairs section i have some numbers and answers. it looks like a replacement, Jensen Concert series. My cab had only one in it when we opened it up, do not know the history. Can't remember, have had it for 40 years now and it was used when I bought it. What was original? Do not know.... 32 in blackface 2x12 from 1967....
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Well, thanks! Any idea how much I'd lay out for a good recone?
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call tonetronix in ohio, check there website ....good a place as any to start
http://www.tonetronix.com/speaker-repair.html
I know nothing about them but i'll probably send a couple of 8" alnico jensens there .....looks like good prices
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> the magnet in under the bell is , well, magnetic....
Magnets hardly fail.
The Voice Coil is many turns of very fine wire. That fails.
Get a $2 speaker. Cut the cone and suspension, take the cone assembly out. Inside the magnet-gap is a paper cylinder wrapped with fine wire held with glue. If you "blow" the speaker before autopsy, you typically find the end-turn of wire melted and thrown right off the paper former, and broken; although you can also have a busted solder-joint and even without over-powering.
The speaker is perhaps worth repair. This is not a DIY job, unless you plan speaker-work as a heavy hobby. The cost will not be a lot lower than the cost of a new speaker. The replacement will normally get a new cone as well as voice-coil: it is too tricky to put a new coil on an old cone. So only the magnet and frame will be old, the working-parts will be new.
It may or may not be worth repair; depends on many unique factors. How good was it when new? How good are available replacement parts? Can it maybe be re-built with parts for a related and more-interesting model? Talk to a good speaker-repair person. Weber VST either does that or can advise.
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Those were very timely and apropos comments and i sure am thinking. I'm wodering if this would be worth more as a museum piece with all the original numbers. As I recall, the sound was very perfect as opposed to an eminence and a fender int ehbox now. They hum and at different frequencies. The fender 42 dollar speaker is 75 watts. I have to take the box open againto document the bad hiss speaker by speaker and then decipher again. My amp man put the fender in that I ordered from a different shop and then when he found this dead Jenson inside, put in an eminence. I do not remember how I got to only having one Jenson dead inside this cab, but it was the 70's / 60's!
So, would this rebuild match another speaker that I could somehow find. I mean, good clean mellow bassy sound that;s quiet would be worth it, and of course a lto of filter cap changes and tube changes down theroad but that;s maintenance.
Any way, thanks for the input.
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Consensus is that this is a Concert speaker similar to a C12P.