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GPA family of loudspeakers

An Introduction to Great Plains Audio and Troy Audio – Keeping the Altec Tradition Vibrant! by Jeff Day

12-07-2019 | By Jeff Day |

If you read my “Today’s Fresh Catch: The Great Plains Audio 802-16G Series II & 416-16B Drivers” post (HERE), you know I am pretty excited about the Great Plains Audio and Troy Audio commitment to keeping the vintage Altec tradition vibrant.

GPA family of loudspeakers

I asked our Great Plains Audio and Troy Audio friends if they would tell us a little about the past, present, and future of Great Plains Audio and Troy Audio (nee Altec), and today I received a nice overview from Santos Oropel, which I have provided for you below. Thank you, Santos!

My chance meeting with Eliseo (Troy Audio), Bill Hanuschak (Great Plains Audio), and Santos Oropel (Troy Audio) in Munich – a great group of guys!

“Great Plains Audio was formed in 1998 after the closing of the Altec Lansing factory in Oklahoma City. It was clear to Bill Hanuschak, who worked for them from 1980 until they closed, that there would be a need for someone to continue the maintenance of the large number of Altec acoustic products in use around the world.

Bill went to EVI/Telex, who had purchased Altec Lansing, with a plan to purchase all of the tooling, drawings, and equipment Altec used to build and service their loudspeakers, and to become their authorized service center for all of the Altec Lansing products that were still under warranty at that time.

In addition, Great Plains Audio assumed repair duties for all of the older, classic products that had served Altec’s customers since its inception with the parts manufactured from the original Altec tooling.

Great Plains Audio is also the source for original parts and warranty service for Altec Lansing Professional, which was a division of Altec Lansing Technologies. This includes all of their speaker products that were built through 2005.

Keep reading:


GPA Compression Driver

Today’s Fresh Catch: The Great Plains Audio 802-16G Series II & 416-16B Drivers by Jeff Day

Today’s Fresh Catch: The Great Plains Audio 802-16G Series II & 416-16B Drivers

11-17-2019 | By Jeff Day |

Being the vintage Altec enthusiast that I am – I have 3 pairs of gigantic vintage Altec loudspeakers in my modest sized home – you can imagine how excited I am by this particular “Today’s Fresh Catch”, the Great Plains Audio (nee Altec) 802-16G Series II compression drivers and the 416-16B low-frequency drivers.

GPA Compression Driver

First let me tell you how impressed I am with the quality of the packaging & packing that the Great Plains Audio drivers were shipped to me with – first rate!

It’s always a good sign when I see companies put that much thought into their packaging & packing, as I know that means they’ve also put an impressive amount of thought into their designs as well, and are proud enough of them to make sure they get to the customer in perfect condition.

Great Plains Audio 802-16G Series II compression drivers. MSRP $900 USD each.

I thought it would be handy for you if I included a copy of the fact sheet for the 802-16G Series II compression drivers.

All of my vintage Altec’s utilize 16 Ohm AlNiCo drivers, so that’s what what Bill Hanuschak sent to me for the review, but for all of you that use the 8 Ohm versions, those are also available as well.

Keep reading: https://jeffsplace.positive-feedback.com/todays-fresh-catch-the-great-plains-audio-802-16g-series-ii-416-16c-drivers/

The 415-8B is the newest loudspeaker manufactured by Great Plains Audio



The 415-8B is the newest loudspeaker manufactured by Great Plains Audio

This project was inspired by Mr. Jean Hiraga who is well known in the high-end world for his crossover designs, redesigns and modification of loudspeakers and amplifier.
After building successful speaker systems using used Altec 415’s he contacted Great Plains Audio with the idea of make them again.

So here it is the brand new 415-8B.

The Biflex principle solves the problem of obtaining full frequency reproduction from a single-cone loudspeaker. It is no longer necessary to compromise between the small cone of minimum weight diameter best for HF reproduction and the larger, heavier cone, optimum for bass response. The Biflex speaker utilizes the principle of dampened cone compliances. The entire area of the speaker cone propagates the low frequencies, and the smaller central cone the high frequencies

Below 1000 Hz , the stiffness of the mid-cone compliance couples the inner and outer sections into a single moving element. Above 1000 Hz , the balanced mass of the outer section prevents the transmission of sound beyond the mid-compliance. The outer portion of the cone uncouples at this point, permitting the inner section to operate independently.

The Biflex design coupled with the famed Altec standards, produces a loudspeaker with specifications for exceeding those of many two and three-way speaker designs.

Inner cone couples to outer cone and the center cone structure vibrates to reproduce frequencies below 1000 cycles



The 415-8B employs an Alnico V magnet for maximum efficiency; the edge wound copper/clad aluminum edge-wound voice coil is situated in a deep magnetic gap to maintain proper cone linearity, this results in extremely low distortion, even during excessive cone excursion.

Although the 415 does have the extended high frequency response to 14,000 Hz alone, because of its efficiency it will match up well with other GPA components such as the 802-8G driver and our N1200-8C crossover for that extended HF output above 20 kHz.

Customers will find that the new 415-8B will maintain the same high quality and reliability as all the other products Great Plains Audio has been building for years

Each member of our team at Great Plains Audio has over 20 years of experience in building high quality audio products. We employ our combined skills and expertise to make the 415-8B one of the best loudspeakers in the world.

The Vintage Altec Experience by Jeff Day

The Vintage Altec Experience by Jeff Day

Let’s start with a short Altec history lesson 

Original text published: https://jeffsplace.positive-feedback.com/the-vintage-altec-experience/

I’ve been wanting to write an article about the “musicality magic” of vintage Altec loudspeakers for a while now, so consider this a mini-installment towards that goal, with – I hope – much more to come.

Let’s start with a short Altec history lesson.

Altec’s origins are inextricably linked to the Western Electric movie theater loudspeaker systems of the mid-1920’s.

The movie theater industry was a new and rapidly growing market in the mid-1920’s and Western Electric was busy providing loudspeakers to movie theaters across the USA.

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GPA 212-8A

Great Plains Audio Model 212-8A

Great Plains Audio designs and manufactures some of the finest loudspeakers in the world. We continue this tradition of excellence with the release of our newest loudspeaker, the Great Plains Audio Model 212-8A. The extension of usable lower frequency limits and the expansion of available dynamic range have placed greater demands on audio monitoring systems. As audio-video facilities are constructed or upgraded to accommodate HDTV, equal attention should be placed on providing a superior acoustic setting. Th e 212-8A will deliver the high definition audio reproduction required for this environment. Recording studios, mastering facilities, and home theater rooms are also......

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GPA 604-8H-III-Rev-02

Great Plains Audio 604-8H III Rev. 2 Duplex

The Great Plains Audio 604-8H III Rev. 2 is more than just an evolution in the classic series of 604 Duplexes, it's an AUDIO REVELATION! For more than fifty years, there has been one studio monitor loudspeaker that has been the defacto standard by which all others have been measured. Though it has been through various generations, it is still known by the simple model number which graced the very first unit manufactured – 604. The popularity of this outstanding loudspeaker grew until, by the 1970's, 604-based systems were used in more recording studios than all other types combined. It’s......

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Regaussing Woofers

Alnico Magnets and Degaussing (Losing their magnetic field)

Alnico magnets, by their nature, are easy to degauss (demagnetize) with drive. They will not change with time and their dependence on temperature is really small – maybe 1% at 100 degrees Fahrenheit. Alnico stability and resistance to back EMF is really good. This is why they make very good sounding magnetic structures. Unfortunately, given a big enough pulse of magnetic energy, they will degauss by up to 3 dB. The sensitivity to degaussing is dependent on the specifics of the magnetic circuit and the length of the coil providing the field. Underhung woofers, midranges, tweeters, and compression drivers do not have sufficient back EMF fields to push the operating point of the structure below the knee. They are essentially stable regardless of input signal. The short-gap, long-coil speakers are the ones that have a problem. A woofer can take a hit of up to 3 dB, if a big enough hit of current takes place. 1.5 dB to 2 dB is more common. The effect does not get better or worse with time, it solely depends on how much current is driven through the coil. The more current, the more field. Once the field is bigger than a certain number, some amount of degaussing occurs. It is permanent (until externally recharged) and will only increase if a larger sustained current hit occurs.

Therefore, if you have a qualifying alnico woofer and you have played it loudly, you have some degaussing. You can have the unit recharged, and it will be fine until you play it again. Exceed the critical level, and it will start degaussing again. If you never do, it won’t ever degauss. Most of these designs trace back to the 50’s and 60’s where 15 – 30 watt tube amps were the rule. They didn’t have the current capability to hurt anything. With the advent of big solid state amps, the current levels went up and the problem started to surface.

Most of the qualifying motors will lose 1 – 1.5 dB, unless they are pummeled. Some of the older 3″ motors with really short magnets will typically be around -3 dB down. They go really easily.

Great Plains Audio can regauss your alnico magnets, if they need it. Regaussing is included free when we replace diaphragms and cones.

Altec Lansing Valencia

Altec Lansing Valencia: Improving a Classic

The Altec-Lansing Valencia 846B is an American audio classic that inspired the development of the legendary Model 19. It shares many similarities with the newer and larger Model 19. There were two versions of the Valencia: the 846A and 846B. For our testing purposes we chose the 846B due to its impedance, and that it was a tuned port enclosure. We had two goals with our Valencias: 1. Make them perform like a Model 19 and 2. Make them outperform a Model 19. Many Altec Model 19 fans will immediately point-out the differences between these two loudspeaker system, and claim......

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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 Lansing Model 19 Cabinet Plans

Follow the links below to download and print sections of the Vintage Altec Lansing Model 19 Cabinet Plans for use in your wood shop. Refer to the Model 19 Cabinet Plans page for NOTES that accompany the plans. Altec Lansing Model 19 Front View Altec Lansing Model 19 Side View Altec Lansing Model 19 Top Down View Altec Lansing Model 19 Bottom Up View Model 19 Material & Finish Data The Model 19 was available in three materials &  finishes as indicated below:   Materials and finishes were applied per the chart below:   Thanks to Art J. for his Photo-Shop efforts in producing these jpg images....

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