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GPA’s Vintage Altec E-Zine

Altec-Lansing 604-8H Crossover Revelations

Enter the H Model... In early 2004 I acquired a pair of 604-8Hs, the last ALNICO magnet duplex model Altec produced before they switched to ferrite magnets. It was also the first Altec duplex model that combined the Tangerine phase plug with a constant directivity high frequency horn and a crossover that utilized dual equalization of the compression driver output. I swapped out my 604Bs for these Hs using the same cabinets, and was immediately impressed  by the differences in output - well controlled upper mids, significantly more high frequency extension, improved imaging detail and more apparent bass & mid bass. What was in......

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Altec-Lansing 604B

Phase Shift Between Drivers

I acquired a pair of 604Bs in the early 1990s, and had them refurbished with new 604E low frequency (LF) cones and new 16 ohm high frequency (HF) diaphragms at the Altec factory in Oklahoma City, Oklahoma. I subsequently used them with Altec N1500A crossovers for years in a secondary audio-visual system. (Follow the Vintage Altec Lansing N1500A schematic link for a look at that vintage series type crossover) My main system had horn loaded Altec 515-8Gs and 909-8As with custom phase corrected passive crossovers, and the 604Bs seemed to lag behind them in a number of sonic areas. In......

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Original Altec-Lansing 604

Altec-Lansing DUPLEX Speakers

Altec Lansing invented the first DUPLEX® Loudspeaker System in 1941 (some sources say 1943 - we're really not sure). Called the "601", it was of the field-coil type and included a small-format HF compression driver mounted to a 12" low frequency loudspeaker with a hole bored through the pole piece of the woofer which connected to a 2 x 3 multicellular horn. Thus began the famous DUPLEX® series of loudspeakers. In 1944, the first of the world-renown ALTEC "604" series of DUPLEX®Loudspeakers (left) was introduced. It utilized a new, permanent magnetic structure of Alnico V, had a 15" low frequency......

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The Altec-Lansing Model 19-MR3: The Loudspeaker That Never Was

The Altec-Lansing M500 Maestro is a largely lost and forgotten loudspeaker, but it is, perhaps, the best the company ever built. It arrived in the final days of Altec-Lansing, Inc., and production was cut short due to the sale of the company. Why is the M500 Maestro important to us today? It provides the framework for what would have been the replacement for the highly acclaimed Model 19. It has been suggested that the new model would have been called the Model 19MR or Model 19-MR3. So the M500 is of great importance to Altec-Lansing fans around the globe. The......

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Altec Stonehenge III

DIY Altec-Lansing Stonehenge III

Perhaps one or the other of you recalls that about two years ago I had two short posts, Björns Altec Stonehenge III replicas as well as the associated. He was lucky to have a beautiful NOS pair of Altec 604-8 G Duplex with AlNiCo magnets, together with related original turnout , which he summarily transplanted into a corresponding test cabinet made from OSB. So now, the adaptation of a corresponding to the original volume, visually far more sedate casing that (almost) without a parallel walls, meets the highest technical standards... Read more at 2A3 Maniac...

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Stevens Dream Altec 604 Loudspeaker

Stephæn’s Altec 604 Dream Speaker

Looking back, it's easy to comprehend why I'm a believer in the concept of thought as object - the notion that we bring into our lives that to which we give our attention. That's how I manifested many of the good things that I am fortunate to have this time 'round. But, sometimes I falter and forget that. I can be quick to immediately assume something is out of reach. That's exactly what happened last October when I learned that the speakers from the room I ranked best in show at RMAF 2005 were beyond my modest financial means. I......

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About Us

Great Plains Audio was born out of the Altec Lansing corporation in 1998. It carries forward the loudspeaker design and manufacturing tradition that began with Western Electric in the early 20th century. Great Plains Audio is the only place where the legendary Western Electric/Altec Lansing sound reproduction technologies live on.

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Oklahoma, USA, 73127