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View Full Version : Rarity! permanent magnet Lansing Monitor 500A



Steve Schell
12-04-2007, 02:39 PM
Part of the fun of chasing rare old speakers and studying their history is that once you think you've seen it all, something new and mind blowing suddenly appears.

My friend Larry Storey, vintage audio hunter/gatherer/rescue expert extraordinaire, found this very significant loudspeaker yesterday. It is a Lansing Monitor 500A, similar to my 500A except for the use of permanent magnet drivers. The story of my 500A, which was also found by Larry back in 2000, can be found here:

http://www.audioheritage.org/html/perspectives/found.htm

The Lansing Monitors were introduced in early 1936, and were built in various forms into the mid to late 1940s Altec era. The basic recipe was a folded W style bass horn (miniaturized Shearer) with one or two woofers, 500Hz. multicellular horn with large format compression driver and 500Hz. dividing network. Mine is an early one, based on low serial number on the 284 driver, early style multicellular horn and its mention in the Lansing Bulletin, which would have been printed by late 1936 or early 1937.

The Lansing Monitors are extremely rare; I've only known of the existence of about a half dozen of them in the modern era. This one is just off the charts rare, as it uses permanent magnet drivers that we didn't know existed at the time this speaker was apparently manufactured. I would peg the date of manufacture as likely 1936 or 1937 due to the great similarity to my 500A, the early Shearer style dividing network and the early style multicellular horn, which was only built for the first year or two to my knowledge.

The high frequency driver is a model 384, serial number 102. It is the p.m. equivalent of the 284 field coil driver, and uses an outer ring magnet design. This is why the label is attached to the rear cover instead of the side; they didn't want to drill and rivet into the magnet. We have not seen this style of rear cover before, with voice coil leads being dressed out the side. The voice coil terminals could not be installed on the top plate like the 284 due to the permanent magnet design. This is the first evidence we have of the 384 model, although there is documentation of later 384B and 387 large format p.m. drivers.

Remember the Salon Iconic that peahix found not long ago and sold on ebay? It was manufactured in 1940 and used the same woofer with monster permanent magnet, model 1518. We had never seen this woofer prior to the appearance of the Salon, though it is described in the literature. The 1518 sold for more than double the price of the 415, its field coil equivalent.

http://audioheritage.org/vbulletin/showthread.php?t=18409&highlight=salon+iconic

Anyway, here are some pictures of Larry's incredible find. It appears to have been hung upside down originally, just like my 500A.

Steve Schell
12-04-2007, 02:43 PM
Here are a couple more pictures:

Hofmannhp
12-04-2007, 02:52 PM
Here are a couple more pictures:

Hi Steve,

seems that the woofer doesn't have a serial number in this times?
Will be wonderful for our registry.

HP

Steve Schell
12-04-2007, 02:58 PM
Hi HP,

There appears to be a loosely attached label on the top of the woofer basket, but Larry hasn't been able to get a good photo of it or see its information as yet due to the difficult location. We're working on this.

Hoerninger
12-04-2007, 03:10 PM
Great find, thank you for sharing!

I would be interested to know how the spider is performed, is there a foto?
The spider of a Klangfilm fieldcoil (ca.1940) I have seen.
Anyway, interesting fotos so far. :)
____________
Peter

Hofmannhp
12-04-2007, 03:15 PM
Hi HP,
..... We're working on this.

thanks Steve......I set a placeholder with your posted pics.....hope you allow this......this is real history.

HP

Titanium Dome
12-04-2007, 04:50 PM
Steve is happy once again!

It has a nice industrial look and patina to it.

mikebake
12-04-2007, 04:58 PM
What kind of venue was it in? Give us the sleuthing story!!

Steve Schell
12-04-2007, 11:50 PM
Hoerninger, my guess is that the 1518 used the same 2" voice coil and Magnavox-supplied phenolic spider as the other Lansing woofers, but it would be nice to know for sure. I'll try to find out.

Hofmannhp, please use the photos in any way you see fit. I posted them here partly to add to our historical record.

TD, I am definitely into shabby chic, but you knew that already.

Mike, I am not privy to all the details, but this speaker evidently once hung upside down in an auditorium, like my 500A. It has holes drilled through the box for the fly hardware in a manner similar to mine. This may have been done at the factory.

Hofmannhp
12-05-2007, 12:50 AM
......Hofmannhp, please use the photos in any way you see fit. I posted them here partly to add to our historical record.
.....

ok Steve,

if you want, take a look what I have done with this records in the Registry.
Actually I no more have a problem to record speakers or drivers where no SN is known, specially in the case of stuff like this from the 30s or 40s.

HP

glen
12-06-2007, 12:45 PM
Very neat find!

Another piece of the puzzle.

Thanks for sharing Steve!

macaroonie
12-06-2007, 04:57 PM
Look how good the bass cone is from behind after 60 years.

JBLnsince1959
12-10-2007, 05:17 PM
WOW!!!!!!!:bouncy:

boputnam
12-10-2007, 05:55 PM
Steve, those are incredible - congrats and thanks for the post(s).

They look like they might have sat in 5" of water at one time. Pity the duty these behemoth cabinets must bear when not being properly looked after... :(