X-onken Xpress - 3
"It is better to travel hopefully, than to arrive", so goes the wise old adage. Google will tell you that the phrase is attributed to the Scottish novelist Robert Louis Stevenson, and the idea is that your focus should not just be your end point, but you should also enjoy the way you get there.
Ah, there lies the point! And Google Maps has finally agreed with that timeless wisdom, and come up with 'scenic routes' in its algorithm. If you are in no particular hurry, choose not the fastest route, but the scenic one, enjoy lots of eye-candy and the pleasures of a slow drive.
The Long Slow Road to Fidelity
A DIYer is in no particular hurry -- as far as I know. They take their own sweet time getting where they initially set out to go. Building speakers too should be suffused with the art and lore of the bygone era. Today when you attempt to re-do the Onken, it should more be as a tribute to the Old Master than anything else. Money could buy many things...maybe most things, but certainly not sincere adulation and tributes...
A Dollop of Theory First
Even today the Onken speaker -- huge by today's standards, with 12 or 15 inch drivers, a volume just shy of 400 litres, double walls made from planks that could range in thickness from a couple of inches to 3.5 inches, and, of course, the signature Onken ports on both sides of the cabinet -- has die-hard devotees, and virtually every hobby forum has an Onken group who yearn to recreate the magic of the Onkens in their homes. Inspired by the "true bass" of the Onken speakers many had attempted to build mini-Onkens with mixed success.
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Quoted from the blog of Volker Heinze, the German researcher and hobbyist:
“ … the central figure, as already described … was Jean Hiraga, a half Japanese and half French-born person. His experiences with Japan’s self-contained audio culture showed completely incomparable detailed aspects, insights and conceptually unusual ideas. This knowledge advantage has been what gave him a head start as audio journalist in France. He acted like a widespread collecting reservoir for hitherto unknown facts and as a rich treasury tank of incomparable information. He did refer about amplifier designers, topologies, speakers, drivers, components, transistors, tubes, PSUs and speaker enclosures (eg:. Anzai WE 300B, recherché de Ms. Iwata, Onken LF enclosures by Koizumi, etc.) at a time when nobody else outside Japan did care about such ideas. The Western Electric single-ended triode 300B for example, the preferred tube driving efficient horn speakers in Japan, was in those days almost unknown in Europe. When he did publish his first articles about Anzai's single-ended 300B amplifier, even in its original home in the US (Western Electric was an American company.), the technology was completely forgotten. It took another five years even in Paris till the ground was prepared and ready for a wider public understanding of what it was meant to be. In the homeland of its technical heritage, the US, it needed another seven years till Joe Roberts in Sound Practice Magazine mentioned this tube and its dedicated amplification concepts – a full 20 years after Japanese audio gourmands did value these products to be the absolute cult…”
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Ah, there lies the point! And Google Maps has finally agreed with that timeless wisdom, and come up with 'scenic routes' in its algorithm. If you are in no particular hurry, choose not the fastest route, but the scenic one, enjoy lots of eye-candy and the pleasures of a slow drive.
The Long Slow Road to Fidelity
A DIYer is in no particular hurry -- as far as I know. They take their own sweet time getting where they initially set out to go. Building speakers too should be suffused with the art and lore of the bygone era. Today when you attempt to re-do the Onken, it should more be as a tribute to the Old Master than anything else. Money could buy many things...maybe most things, but certainly not sincere adulation and tributes...
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| Early Work by Koizumi at the Onken Seisaku company |
As mentioned earlier, our first project is a 'micro-sized' tribute to the Sumo wrestler from Japan -- the Onken ported speaker. I have on an inspired moment chosen to name it X-onken -- an Onken speaker with an X-factor .. something that is magical and good!
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| An Onken Speaker with Cellular HF Unit |
Onken was Koizumi's fitting answer to Jensen's Ultraflex, and it easily floored the giant to rule theatre sound for decades. Onken in Japanese meant "quiet and dependable", and perhaps 'tough and businesslike', as we would like to say today.
Onken was Koizumi's brand and the company name. Coupled with Japanese tube master Anzai's Single-ended Western Electric 300B valve amplifiers, Koizumi's Sumo pugilist brought the ceiling down in most Japanese theatres with its like-like bass. Mesmerized by the auditory magic of the combo, young Hiraga set out to introduce and popularize the design in the west. Sadly, today we only remember the brand, thanks chiefly to Hiraga's highly popular articles in the L'Audiophile journal. (*)
A Dollop of Theory First
Even today the Onken speaker -- huge by today's standards, with 12 or 15 inch drivers, a volume just shy of 400 litres, double walls made from planks that could range in thickness from a couple of inches to 3.5 inches, and, of course, the signature Onken ports on both sides of the cabinet -- has die-hard devotees, and virtually every hobby forum has an Onken group who yearn to recreate the magic of the Onkens in their homes. Inspired by the "true bass" of the Onken speakers many had attempted to build mini-Onkens with mixed success.
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| A Beautiful Onken System |
A positive fallout of the Covid period lockdown for me was enough and more time on hand to explore this idea. A few months and quite a few "cut and paste" prototypes later, our little group fell under the magic spell of the micro-Onken. Yes, it was indeed a David when compared to the original Goliath. And all it lacked perhaps was the "authority" of the "weight" of bass punched out by a 15 incher in a giant cabinet. Bass was "true" in character and easily belied its 'baby' proportions.
Overcoming the many drawbacks of the Jensen bass-reflex design, while at the same time preserving the efficiency of the 'open design', meant one had to take a giant side-step. Koizumi's genius and brilliance shone through when he decided to part ways with the resonant system of the bass-reflex, and went ahead to make his speaker into a damped low-pass filter, with ample resistivity to dampen and smoothen the response.
Most of us know how difficult it is to design a 'good' sounding bass-reflex speaker. Today many design aids exist, into which you could "plug in" the T-S parameters of the drivers and arrive at cabinet sizes and port lengths etc. Easy? The laugh is on you, unless you know exactly what you are doing, and you have infinite reserves of patience. The 'design' part is the easier half; building and tuning a bass-reflex into one that keeps "booming bass" at bay is more a black art than anything else. Those who have attempted to replace the driver of a bass-reflex design know the sweat and tears that go into the exercise, to speak nothing of the cuss words!
Overcoming the many drawbacks of the Jensen bass-reflex design, while at the same time preserving the efficiency of the 'open design', meant one had to take a giant side-step. Koizumi's genius and brilliance shone through when he decided to part ways with the resonant system of the bass-reflex, and went ahead to make his speaker into a damped low-pass filter, with ample resistivity to dampen and smoothen the response.
Most of us know how difficult it is to design a 'good' sounding bass-reflex speaker. Today many design aids exist, into which you could "plug in" the T-S parameters of the drivers and arrive at cabinet sizes and port lengths etc. Easy? The laugh is on you, unless you know exactly what you are doing, and you have infinite reserves of patience. The 'design' part is the easier half; building and tuning a bass-reflex into one that keeps "booming bass" at bay is more a black art than anything else. Those who have attempted to replace the driver of a bass-reflex design know the sweat and tears that go into the exercise, to speak nothing of the cuss words!
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| Another Onken Classic |
It is precisely at this juncture that the Onken principle comes to our aid. Thanks to Koizumi San's inspired design, our task is considerably simplified. The narrow ports of the Onken design are resistive in nature, making it highly driver T-S parameter tolerant. This means you could try out a variety of drivers in the same box without affecting performance or tuning much.
This for the DIYer is a double bonus. No headaches / head banging trying to achieve correct tuning and the resulting bass of passable quality. What a relief! Second, it is easy to try out the proto with whatever drivers you could lay your hands on. Evaluate their performance and later go for a pricey driver with better performance in the mids and highs, and suiting your type of music to a T, and you could be dead certain that the overall performance will only be better. Another bonus is that the double-walled sides of the Onken cabinet adds rigidity to the box even when we use thin material (as we are doing here). What more could the DIYer ask for?
This for the DIYer is a double bonus. No headaches / head banging trying to achieve correct tuning and the resulting bass of passable quality. What a relief! Second, it is easy to try out the proto with whatever drivers you could lay your hands on. Evaluate their performance and later go for a pricey driver with better performance in the mids and highs, and suiting your type of music to a T, and you could be dead certain that the overall performance will only be better. Another bonus is that the double-walled sides of the Onken cabinet adds rigidity to the box even when we use thin material (as we are doing here). What more could the DIYer ask for?
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| Onken with dual Altec Drivers |
Tall promises indeed! Now it is time for you to jump into the build arena and verify if those promises will stand the test of "true bass" as judged by the finest among test equipment -- your ears!
Ready?? Steady, Go ...!!
============
(*)
Quoted from the blog of Volker Heinze, the German researcher and hobbyist:
“ … the central figure, as already described … was Jean Hiraga, a half Japanese and half French-born person. His experiences with Japan’s self-contained audio culture showed completely incomparable detailed aspects, insights and conceptually unusual ideas. This knowledge advantage has been what gave him a head start as audio journalist in France. He acted like a widespread collecting reservoir for hitherto unknown facts and as a rich treasury tank of incomparable information. He did refer about amplifier designers, topologies, speakers, drivers, components, transistors, tubes, PSUs and speaker enclosures (eg:. Anzai WE 300B, recherché de Ms. Iwata, Onken LF enclosures by Koizumi, etc.) at a time when nobody else outside Japan did care about such ideas. The Western Electric single-ended triode 300B for example, the preferred tube driving efficient horn speakers in Japan, was in those days almost unknown in Europe. When he did publish his first articles about Anzai's single-ended 300B amplifier, even in its original home in the US (Western Electric was an American company.), the technology was completely forgotten. It took another five years even in Paris till the ground was prepared and ready for a wider public understanding of what it was meant to be. In the homeland of its technical heritage, the US, it needed another seven years till Joe Roberts in Sound Practice Magazine mentioned this tube and its dedicated amplification concepts – a full 20 years after Japanese audio gourmands did value these products to be the absolute cult…”
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