Friday, February 19, 2010

Lowther Hegerman Teak 1950-1951 Pair

I don't usually post items from ebay but this is just stunning. This could be apart of any audio history museum. A pair of early 1950 Lowther Hegerman speakers in the USA. Not only are the speakers rare but the right up is a Lowther, Hegerman, and Voigt mini history lesson. Check it out here

These pictures and information are all from the ebay seller. Youtube video click here.

Lowther Hegeman Reproducer History
This groundbreaking speaker resulted from a collaboration between legendary american audio designer Stuart Hegeman and Donald Chave of Lowther UK. As it was 3 times the price of the next most expensive Lowther speaker at the time and had very short production run between 1950 &1951 - No one knows for sure how many Lowther Hegeman Reproducer speakers were made - the best production estimate is in the 20-30 unit range. At the time Mono was the dominant playback format so these speakers were almost never sold as pairs. Hegeman & Chave desired to take the Lowther/Voigt full range single driver concept to a higher level and this both front & back horn loaded speaker design was the result. No doubt part of the high cost during its day - was the Plaster-of-Paris folded horn that loads the front output of the PM4 and the very elaborate horn loaded bass cabinet taking the output from the rear of the driver



The Designers

Stuart Hegeman

Stu Hegeman is revered by high-end audio engineers as he was one of the first focus on components and speakers designed specifically to sound like music and not just measure well for specifications sake. For example he was first to identify negative feedback (a common method amp designers use for reducing measurable distortion) as a source of unusual distortion in itself, which was undetectable by the instrumentation of the day. As measurement methods evolved, Hegeman’s philosophy was proven true. Like many geniuses in their respective fields Hegemans’s ideas were so far ahead of their time they were scoffed at by his peers, but are now universally accepted. His theory of amplifier design based on ultra-wide frequency response, stating the frequency response of an amplifier should not be limited to the range of human hearing (20 to 20,000 Hertz) but should also be extended to the fringe areas of the audio band (10 to 40k Hz), was laughed at. But two decades later nearly every manufacturer adopted this principle to some degree.

Unlike so many other audio engineers Hegeman was not limited to a specific area of audio design. He made brilliant breakthroughs in almost every area of audio, including FM tuners, preamplifiers and loudspeaker design. He even invented a large screen projection tv in the 50’s and handmade a working video recorder prototype in the 60’s long before anyone knew what these were. He also invented the soft dome tweeter and the omni-direction speaker system. His theoretical work on loudspeaker dispersion and electronic sound in general have been snapped up by manufacturers and still serves as the basis of their product lines to this very day.



Donald Chave
Donald Chave was a true believer in the philosophy set forth Lowther founder - Paul Voight - who had the vision, technical abilities, and marketing prowess to take the company to the next level. Chave updated and expanded a series of permanent magnet full-range drive units (that are still made today, fundamentally the same) and produced many speaker enclosures that extended the frequency spectrum of these highly sophisticated drivers. Donald Chave was also wise enough to recognize true talent and humble enough to seek help. So in the late 40’s Chave implored Hegeman to come to Britain and work with him on a new flagship loudspeaker for Lowther. Hegeman was a big fan of the Voigt/Lowther philosophy and his talents and passion were well suited to maximize the sonic benefits of this unique system.



Paul Voigt
In 1934, Kent England, an alliance between Paul Voigt and O.P. Lowther brought forth one of the most influential loudspeaker manufacturers of all time, Lowther. The Lowther/Voigt union was based upon Voigt’s invention of the “Domestic Corner Horn” a home hi-fidelity loudspeaker design he started developing in 1924 (that’s 22 years before Paul Klipsch’s famed corner horn) Voigt was an electronics genius who broke new ground in the fields of radio circuitry, recording cutters, microphones, amplifiers, transformers, pickups and loudspeakers. He is one of the unsung pioneers of sound reproduction, whose brilliance and contributions to audio never received its due recognition. His work laid the technical groundwork for entire industries and his theories of sound reproduction continue to prove more accurate as time progresses. Though the average audiophile probably never heard of Paul Voigt he has the highest respect of the generations of audio designers who succeeded him. Peter Walker the inventor of seminal electrostatic speaker designs said “I can think of no single man who has done more in the field of audio” - Paul Klipsch also had tremendous respect for Voigt, whose own speaker designs were influenced by Voigts.



Lowther Sound Reproduction Philosophy

In a nutshell, the full-range Lowther philosophy is that the audio spectrum should be covered by a single driver, believing the incorporation of multiple drivers and the required crossover filter rob the music of its true natural presentation and introduce distortion and phase shift that is unavoidable. The difficulties of developing a full range single driver system are numerous, yet its strengths are just too good to overlook. Nearly all conventional multi-driver speaker systems put a crossover in the mid-range to split the signal to the bass driver and the tweeter. Music is made up of approximately 70% midrange and this is the most critical hearing region, where our ears are most sensitive. If the midrange is off then it really doesn’t matter what the other ends of the frequency range sound like, our brains are convinced what we are hearing is not the real thing. There is no way around it, crossovers introduce phase and balance problems that cause deterioration in detail, transparency and imaging. And the design variations of each driver in a multi-driver system, with differing time-constants and sonic characteristics, further blur the sonic picture being presented.

Theoretically, a perfect speaker system would be a single driver with the ability to reach all the frequencies necessary to reproduce music. This is the goal designers have been longing for since Paul Voigt first developed his single driver full range approach. Despite the loss of some of the lowest and highest frequencies, the gains produced by lowther's approach in coherency and naturalness are well worth it. Especially if your musical tastes run towards classical or acoustic instrument. For reproducing the human voice there may never be a design surpassing the coherency presented by the Lowther designs.
The Lowther-Hegeman is one of the best executions of the Lowther single driver full-range philosophy. It extends the frequency range of the PM4 driver to amazingly wide proportions and disperses music uniformly over a wide angle. It utilizes a folded horn for high and mid frequency and a rear-loaded horn for bass response. The Lowther-Hegeman utilizes an elaborate folded “W” bass horn specially designed to exploit the rear output of the Lowther PM4 driver. The front-horn is a unique dual outlet double rate flare horn crafted of Plaster-of-Paris.



Lowther PM4 Driver

The P.M.4 driver was developed for, and first used in, the Lowther-Hegeman system in 1951. It is a marvel of audio science that is still being produced today by Lowther UK. The PM4’s in these Hegeman speakers are the original greenbacks with the no-longer produced Ticonal-G magnets. The shape of the magnet is of considerable importance, enabling enormous magnetic force into the gap. The PM4 produces an astonishing flux rating of 24,000 Gauss. This in combination with an incredibly light and nimble cone (only 6.5 grams of moving mass) equates to speed, which, to your ears, translates to incredible sonic detail, superior natural reproduction, wide dynamics, and outstanding transparency.



PM4 Driver Restoration

In general all Lowther drivers require new cones over time because of the natural deterioration of the delicate surrounds and spider assembly. These drivers have been re-coned a total of three times over the past 55 years. The original owner had them re-coned twice, once in 1971 and again 1997. We have, and will include, the original letters of correspondence with Lowther. At the time of his last re-cone Lowther updated the frames to the rounded style that you see on Lowther speakers today, this was common practice. When we received the Lowther-Hegemans and inspected the PM4’s we felt it was best to re-cone both drivers. We wanted to return the PM4’s back to as close to original as possible in both performance and appearance. We questioned many Lowther experts and the name that kept on coming up was Ines Adler of Full Range Speakers in Berlin Germany. They were the only ones who re-manufactured the original style square-frames and they utilized cones that best matched the electrical and sonic characteristics of the original 1950 era PM4 cones. We sent both drivers to Fullrangespeakers in Germany where they were expertly re-coned and they also fully re-magnetized the original Ticonal G magnets. We could not have been happier with the results as the drivers perform to a level exceeding our expectations, with a look and sonic character archetypal of the original 50’s versions.

Lowther Hegeman Sound Today

Fans of Lowther speakers, and other fullrange designs, will absolutely love the Lowther Hegeman system. It is amongst the best, if not the best, representation of what the Lowther sound is all about. If you like full range electrostatic or planar type speakers, you will probably be more impressed with the Hegemans, as they have all the favorable characteristics of those designs with a whole lot more dynamic impact. Their sound is akin to a pair Quad 57’s on a heavy dose of steroids. If you are a fan of classical, jazz, orchestral, acoustical, opera, chamber, folk, or any other music genre where the primary source is of natural, non-electronic instrumentation, you will love the Lowther-Hegeman system. What they do better than any other system is their incredible natural sonic depiction of human voice and acoustic instrumentation. A properly recorded orchestra played back through the Hegeman’s produces an eerily life-like experience. Tracks that capture the melodic nature of a woman’s voice, will send shivers down your spine. Conventional systems can’t compete with the Hegeman’s on these aspects. The system has a level of coherency, clarity, speed, naturalness and pure musical energy that is unmatched. What they accomplish with just a few watts of single ended triode amplification is truly astonishing.

Traditionally the biggest criticism of Lowther speakers in general lack of lowest bass, which is not entirely true. Larger cabinet systems such as the Lowther-Hegeman do make it down to the lower bass regions that includes a vast majority of recordings, yet in comparison to many modern high-end multi-driver systems they do lack the extreme bottom end. If your primary listening tastes are rock, dance, techno or other bass heavy music this may not be the speaker for you, but they are such a wonderment everywhere else in the frequency range that you may simply not care about the missing lowest bass frequencies or find it a better option to locate a worthy subwoofer to get the last few Hz.

Original Owner

The original owner of this amazing set speakers was a decorated WWII Vet and a Lieutenant Colonel in the United States Air Force. During the 1950’s he was stationed in Formosa I (Taiwan) and frequented Hong Kong . In 1958 he purchased this pair of Lowther Hegeman speakers along with a matching equipment cabinet and components from The Radio People, Ltd on 31 Nathan Road, Kowloon, Hong Kong. For those of you who don’t know, The Radio People, Ltd was a Mecca of hi-fi in Asia that specialized in Europe’s finest audio gear. It became a famous destination point of American service men and all music lovers of Asia. It was one of the only authorized dealers of all major British equipment manufacturers in the 50’s. When the Colonel came back to the US he brought his equipment with him. He enjoyed this system for the rest of his life in his home in Phoenix AZ. Over the years he maintained the system, re-coning the pm4 drivers when necessary. He kept mail correspondence of these services from Lowther UK in 1971 then again in 1997 from the Lowther Club of America.

Some More Detail:

According to the original paperwork the wood enclosures were crafted by The Radio People, LTD while the PM4 drivers and Plaster-of Paris horns were imported from the UK. This was the common business model of the day for all British manufacturers because of the high cost of labor in the UK, shipping complications, and taxes/duties. If you were going to be a Lowther Distributor anywhere else in the world other then the UK you had to invest in a first class woodworking shop - which The Radio People did - Craftsmanship of the enclosures is absolutely phenomenal. They were built to precise specifications as provided in the original plans (included) using marine grade plywood - all vital joints were dove-tailed and tightly bonded. Veneer is high-grade teakwood of 3/32” thickness with a hand rubbed oil finish. There may very well be no other pair in existance with this teak finish.

Cabinet Condition - The cabinets of the Lowther Hegeman were luckily in phenomenal shape for their age. There were no rings, stains, scratches or gouges. The finish was is little dry and the areas were the woodgrain lines are show a slight raise. Also there is a slight variation of color between the two cabinets because of their placement in the original owners house and proximity to the incoming natural light. Using a light coast of Howard’s Restor-A-Finish we were able to bring them back to very good condition. The luster and color of the teakwood is outstanding. All of the original seals on the cabinet and plaster-of-paris horn have been replaced.

Bass Cabinet Illumination
- As per the factory build plans - the bottom of each Lowther-Hegeman cabinet is a small removable panel. Inside is a light-bulb and fixture attached to a long stand. It seems as a final touch to the Lowther-Hegeman system an illumination source, which provides just enough light to cast shadows of the louvered bass cabinet, to set ambience and really accentuate the beauty of one of the most incredible speaker designs of all time! Both the bulb and fixture date back to 50’s. This set has one light-bulb and is missing the other - it is a bayonet style lamp and should not be hard to find a substitute if the new owners desires the illumination

Speaker Wire - The speaker wire has been replaced in both speakers with high purity copper cabling

Matching Equipment Cabinet - top cabinet lifts up and has a cutout for a Thorens TD-124 on the right and an area for drop down components on left - An amplifier can be placed on the bottom left and there are drawers for media on the mid and bottom right - as mentioned this is an optional item if the winning bidder wants it included. Dimensions - 34"W x 44"W x 20"D

Lowther Hegeman Dimensions - 46"H x 44"w x 24"D

Shipping - I can ship these speakers fully insured worldwide and no expense will be spared in order to protect this very rare set when it comes to packing materials. All interested parties should e-mail me their Postal Zip Code, City and Country as early as possible for shipping cost estimates

Final Note - Odds on finding another pair of Lowther-Hegeman loudspeakers, anywhere in the world, so closely matched and in impeccable condition, are slim to none. We have spoken to many Lowther enthusiasts, many in their 80’s, who have never even seen one. The only other Lowther-Hegeman that we were able to track down is located in the Lowther Voigt Museum in England, and that is a single not a pair. In the vintage audio world this is the rarest it gets. A system with a heritage rooted into the very beginnings of hi-fi and a lasting impact on today’s designs.

10 comments:

  1. This comment has been removed by a blog administrator.

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  2. Do you have the plan of this speaker for sharing :-)

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  3. I wish I did. I bet the HF horn is a PITA to build.

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  4. its very snice retro site . ineed help ihave this retro wharfardale w30 d mark II spkrs . the caps need to change . iread on the capacitor 8uf 50 m.v. 85c , ilike to ask wich capacitor ishould go for ? seems dificult to find 8uf cap can ireplace to 10uf ? any help will be deeply apreciated . paulo wilson

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  5. when I was a kid in Hong Kong I was a regular visitor to Albert Chan owner of the Radio People Ltd. This was in the 60's and 70's. I have 2 pairs of speakers built by them. a 1959 pair of Ge'Go Orthophase OR3 W4 and a 1971 pair of KEF Chorales in their original packaging. There was a strange shop in HK in the 70's that sold Jordan Watts and Lowther but I cannot remember its name. Could have been The Elephant Radio Company.

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  6. I am jealous. Hong Kong in the 60's and 70's... WOW.

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  7. It can be stated that a full range driver is a good way to go if one is interested in the accurate reproduction of music. One doesn't have the phasing issues from multiple drivers nor crossover networks. One of the main disadvantages of using a single driver to cover the full musical range, is that the driver must be very carefully designed to have a smooth response over that range. Especially if peaks are to be avoided anywhere in the spectrum, especially the midrange. Such a driver would likely be of a rather low efficiency.

    With the Lowther Hegeman, it appears we have the best of both worlds. A 2-way speaker system using only one speaker. From the looks of the pictures, it appears that the HF horn is of a partial reentrant design, but without the harsh bends one sees in a PA horn. The idea of a using a single full range driver here seems to be a real sensible design, the different horns themselves serving as sort of an acoustical crossover. Considering that a horn is an acoustical transformer at it's core, coupling the radiations from the small diaphragm to the room air. If I were to venture a guess judging by the HF horn, I'd say this probably has a "crossover point" of about 400-500 Hz, the area where the HF horn experiences cutoff, and the LF horn ceases behaving.

    I'll have to admit that many years studying the art, it's easy to become jaded. Because of this, I don't impress all that easy. Looking at these made an impression on me in many places. Not only the design, but also the history and care that has been taken of these rare pieces. I am absolutely sure that the winning bidder is thoroughly enjoying them.

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  8. From reading up on Stew Hegeman it looks like the system was designs with Hegeman's preferred crossover point of 200Hz being the guiding factor.

    The man is a audio genius also G.A. Briggs they both used their ears and hearts when it came to creating loudspeakers.

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  9. Forgot to add this Hegeman patent the citations on the patent is a gold mine of information as well. http://www.google.com/patents/US3032136

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  10. Hello,

    Has all of this been sold?

    Please advise.

    Best,
    sandmandreams1@gmail.com
    Sandra

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