Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Cabinets-Speakers => Topic started by: Shrapnel on May 18, 2009, 01:39:00 am

Title: Jensen P12RJ
Post by: Shrapnel on May 18, 2009, 01:39:00 am
What can anyone tell me about these speakers?

1)
P12RJ, C7200
P8465-01
220145

2)
P12RJ,C7198
P8464-01
220143

both came out of a Lowrey Organ (same one)

Closest data I can get is they're both Jensens, with permanent magnets, 12" Guitar amp quality (the R), made in late 1961. (45th week first one, 43rd for the second)

What I don't quite interpret is the C7xxx codes, and I assume the P846x-01 are Lowrey part numbers. How does a RJ differ from a R, other than magnet size?

Also heard these were 16 Ohm, 20-25 Watt speakers.
Title: Re: Jensen P12RJ
Post by: FYL on May 18, 2009, 06:26:07 am
R = power rating/voice coil dia, here 12 watts/1" (curent ratings for Italian Sica/Recoton models are different)
J = bass/mid. Wide range models from the Concert series have no suffix.
Cxxxx = type of cone (straight, curved, ribbed, smooth, molded, seamed, etc...)
Title: Re: Jensen P12RJ
Post by: Shrapnel on May 18, 2009, 01:25:54 pm
Can't be 12 watters, can they?  The two listed above are paralleled in an Organ Amp rated at 30 Watts. (2-7591 tubes).

But thanks for the heads-up on the added J... they were set up, using a crossover network (12dB/Octave), with one Bogen branded (Quam-Nichols mfg.) 8".
Title: Re: Jensen P12RJ
Post by: FYL on May 18, 2009, 01:40:33 pm
Quote
Can't be 12 watters, can they?

They were spec'ed at 12 watts by Jensen...

Title: Re: Jensen P12RJ
Post by: Shrapnel on May 18, 2009, 05:22:42 pm
Out of curiosity, when were those specs published?
Title: Re: Jensen P12RJ
Post by: FYL on May 18, 2009, 05:40:14 pm
Quote
Out of curiosity, when were those specs published?

I would say early to mid '50s, judging from the line-up.

Here are the specs from a '55 brochure
Title: Re: Jensen P12RJ
Post by: Shrapnel on May 18, 2009, 09:08:15 pm
I probably should have done this sooner, but here is a pic of one... well not the EXACT ones I have, as this one is produced during a different week... but it is the same model, and year as ONE of the two. (Both look alike from the basket side, other than week, and Cxxxx code)

the '55 is closer,, but still these were manufactured in '61 I believe.