[Jukebox-list] 12 inch speaker replacements

James Alexander jalexandercc11 at att.net
Fri Sep 14 06:26:04 PDT 2012


Gentlemen:

I'm attempting to provide an accurate answer to this question.   The normal 
equipment used in a Seeburg 222 juke consists of an SHFA-1 stereo 
amplifier---this is a tube type amp with push-pull 6973 output stages that 
generates about 20 watts per channel.  Sometimes later model Seeburg amps (also 
with 6973 outputs) are dropped into 222 jukes because they can be easily 
substituted, are a littlle less complex and therefore are easier to repair, and 
support the later motorized remote volume control function.  I'm assuming that 
your quoted 36 watt figure is a mistake. 


The speakers used in a 222 juke are 12"  16 ohm full range high-resonance single 
cone speakers. There is one 12" speaker per channel, apparently mounted on a 
baffle-board with a separator.   The 2 medallions mounted on the front spkr 
grills have portruding screw fasteners into the area in front of the speaker 
cones, which might be a limitation to using certain performance 12'" co-axial 
speaker driver.

Seeburg purchased raw-frame speaker drivers from manufacturers that were in that 
business,(like most other juke manufacturers) rather than manufacturing them on 
their own. They bought drivers from Utah, Jensen, Oxford, Heppner and possibly 
others.   Most of these US manufacturers are now out of the business.   In 
recent times, the physical sizes of speaker system designs are being reduced to 
offer more performance out of less bulky size units.  Speaker efficiency 
(conversion of audio signal to acoustic energy) isn't much of a concern because 
it's inexpensive to assemble high wattage audio amp designs very cheaply today.

The few places one can turn to buy high efficiency speakers are the pro sound 
business and the musical instrument (guitar and keyboard apps).  Lots of 
raw-frame speaker choices exist there, with not so many choices available in 16 
ohm drivers.

The former US Jensen Corp was famous for making many OEM driver units to other 
electronics manufacturer, including a strong legacy in the MI 
business.   Italian speaker manufacturer Sica bought the rights to the Jensen 
name and is currently building replicas of Jensen's most popular MI driver 
units, using modern manufacturing methods.  Sica is making some recone kits to 
retrofit original US built Jensen models.If you go through the current 
Sica/Jensen catalog it appears that there are many near-similar 12" speakers, 
each having minor magnet and cone construction differences.  For MI 
applications, this makes a big difference in performance, where guitarists 
frequently operate their speakers near the limits of their capability.  This 
isn't usually the case when a speaker is used as a playback device.    For a 
jukebox app, there's little to be gained by spending the additional money to buy 
any of the Alnico magnet designs versus the ceramic magnet designs.     In a 
cone construction, look for a design that yields a close to linear freq 
response.  Certain guitar,keyboard and organ speaker designs use cones that 
generate a peaky freq response, necessary to get the tone that musicians are 
looking for. 


To sum up, if you are looking for close to the original sound performance you 
had in a single cone full range speaker, there are several Sica/Jensen designs 
that can fill this need.   These are the PAC-12N, the Mod 12-70 and the Mod 
12-50.  All are available with choice of 4, 8 or 16 ohm voice coils and have an 
MSRP of under $100 ea. 


If you'd like to upgrade the sound performance of your 222 drivers to a speaker 
choice with improved specifications over the originals, consider any of the 
following:

Eminence Beta 12 LTA  (#290-409) is a 12" single-cone extended range speaker, 
employing a whizzer cone attached to the 12" cone.   Available in 8 ohms only.

You can "build" an extended performance 12" Eminence brand coaxial speaker by 
assembling the following parts:

Eminence Beta 12-CX 12" co-axial woofer (#290-504) 8 ohms
Eminence ASD-1001 high freq driver (#290-525) 8 ohms
Eminence PXB2-2K5CX  (#290-635) board-mount 2500 Hz 2 way 12 db/O crossover 
ntwk.  8 ohms in/out

I'd buy an 8 ohm Lpad  (20 watts or better rating) to install on the HF output 
leg of the crossover network in order to have the HF driver output match the 
performance of the 12" woofer cone.  The acoustics of the spkr cabinet and the 
listening space will haver a big influence on this setting.      Buying the 
above combination  (approx $175 total MSRP per speaker pkg) will yield several 
db more level (higher efficiency than the single cone 12" spkr)and an extended 
"sparkling" high freq response compared to the original devices.   An Eminence 
coaxial speaker will clear the medallion mounts in the 222 cabinet and doesn't 
require any special cutting.fitting, etc.
You will need to buy a couple of 8 ohm 20 watt power handling resistors in order 
to perfectly match impedances.

All the part numbers in parenthesis are Parts Express SKU numbers (an 
electronics distrib in Ohio with an on-line store) for the Eminence components.  
You can find suitable 8 ohm LPads and resistors there.

Before buying ANY replacement driver units, check the measurements and 
specifications to make sure they will fit your application.  I've verified that 
these are electrically/acoustically good matches.

The Eminence brand components have become today's choice for those who design 
and build custom speaker systems.   These components are widely available in the 
US and Canada. 


Other pro-sound 12" speakers that can fit your 222 juke come from B & C 
,Selenium, Atlas-Soundolier, Lowell and  JBL Pro Audio.  Any of these coaxial 
speakers, equipped with crossover will cost in excess of $250US  MSRP ea. if you 
are buying these as new devices.

Hope this helps address your 222 speaker question


Jim Alexander
         




________________________________
From: Carl Haines <cshaines at verizon.net>
To: Jukebox mailing list <jukebox-list at lists.netlojix.com>
Sent: Thu, September 13, 2012 3:52:11 PM
Subject: Re: [Jukebox-list] 12 inch speaker replacements

On Sep 13, 2012, at 2:12 PM, ascott822 at aol.com wrote:

> Please suggest modern replacements for 12 inch speakers in the Seeburg 222.  
>The amp is a 36 watt.  Customer wants them replaced, not reconed.  I've been 
>considering the Jensen vintage ceramic rated at 50W or the Jensen Jet series 
>rated at 70W.  Would I be going wrong with either of these?  Please advise.  I 
>want the box to sound great, if possible.  Allen

What is the customer complaint and how is the rest of the sound system 
equipped?  What is the amp?  What is the cartridge?  Is the crossover network 
present?  The reason for asking is that there are other areas that could be 
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