Interesting new fullrange drivers out of Japan

Recently there have been some interesting new fullrange drivers coming out of Japan . . . well, actually "coming out" may not be the right phrase since nobody outside Japan -- at least that I know of -- has yet to hear them. But they seem to have a devoted following inside the country.

Here's a link to a current Internet auction in Japan (all Japanese but a link to an English explanation is provided):
Exact E-12D/SPL alnico 5-inch fullrange driver



Earlier this same manufacturer had an even wilder (and even more expensive -- by a large margin) 6.5 inch driver up for auction:



In any case, if esoteric fullrange drivers interest you, this company may take the cake.

Imaginary coaxial loudspeaker?

"Imaginary coaxial loudspeaker?" Where did it say that? One thing is for sure, though -- there is no comparable system (at least that I know of) in the world of audio (apparently it was patented), and this is the hardest part (and the most important part) of the technology to comprehend in order to understand these drivers. I have been following them in Japan for some time now and read a lot about them in Japanese. (There is extensive documentation available in Japanese.) I finally came to the conclusion that I needed to hear a pair, precisely because there is nothing comparable on the market. Sometime this month I'm going to review a pair at my home, and if I like them, they're staying. Not the top of the line Permendur models, though. I couldn't afford them. I'll be listening to their basic 5-inch drivers. My current loudspeakers are large Pioneer 3-way bookshelf speakers (list price about $4,000/pr) so there should be a world of difference. If I decide to keep the Exact speakers, I'll sell the Pioneers to help defray the cost.

Say, that *IS* a hoot!

I never noticed that label on the magnet before! That is funny. After reading the maker's explanation, I understand why he used that phrase, but still. Gee, I wonder if he'll let me pay with imaginary money?

The Japanese do have a way with naming and labeling products. A "creamy powder" coffee creamer is called CREAP. A popular drink similar to Gatorade is called Pocari SWEAT. And Mitsubishi sells a 4x4 on/offroad vehicle here in Japan that had to be renamed for overseas sales since the Japanese name is Pajero, which is Spanish slang for a guy who masturbates! Anybody care to drive around in a Mitsubishi Masturbator?

I'll have to contact the maker and suggest he come up with a label that is a little less entertaining for us foreigners.

About the price at the current auction

Yes, the starting price at the current auction is 147,000 yen for the pair. Speaking as one who has read nothing but raves for these drivers among Japanese users, and as one who as drooled over these auctions for well over a year now (the sheer variety of the drivers he has auctioned is amazing for what is essentially a one-man operation, although it is true that they have all tended to be variants of a few basic models), I feel that these particular drivers are a bargain at this price. Mind you, I haven't actually heard them! But here in Japan he can sell them as fast as he can make them (which isn't very fast, to be sure). Some guys have a pair that they listen to, and several additonal pairs that they just wanted to collect, so they sit around in their original cartons doing nothing. And some fellows are actually using these for home theater! I'm sure it sounds great, but one could see LOTR in the movie theater many times for the cost of a system based on these drivers! In any case, if I had 147,000 in my pocket, you can be sure I would not have posted information about these drivers! (Except possibly as a review). I can't wait to test drive some of this family of fullrange driver at my home later this month. It is something I have been looking forward to for over a year now.

Unsurpassed sound, but expensive and slow in coming

Dear Thomas,

I purchased an "ancient" pair of Exact drivers used and sent them to the manufacturer, Mr. Sano, for rebuilding into a completely new type of driver, very similar to his most recent drivers. However, since they are not part of his regular production line, it is essentially a one-of-a-kind special order job. In return for keeping the cost to a minimum, he only works on them when he has spare time, so it is taking forever (well, the better part of a year now) for them to get finished.

I have had several opportunities to hear these drivers, and I am convinced that they represent one pinnacle of sound reproduction. Among fullrange drivers, they are without equal. No other driver comes as close to being a true fullrange. Their high end is simply outstanding, extending flat out to 18kHz and then gradually rolling off. Their bass is quite solid as well, although it varies depending on the model. They are flat (within 3dB) down to 40Hz for most of the 12cm models, and down to 30-35Hz for most of the 16cm models. The models that perform best with the deep bass, going down to around 25Hz, are extremely expensive even by Exact standards.

And all the Exact drivers are expensive compared with other fullranges. The "standard models" cost about what you would normally pay for some of the better Lowther/AER drivers, and the most high-end models cost more than anything available from AER. My personal feeling is that it makes sense to get some of the less expensive drivers and pair them with a subwoofer if one requires faithful reproduction of the lowest bass. Not only is the total cost cheaper, the drivers will have better power handling if used with a subwoofer. Having said that, the lowest string on an upright bass is about 40Hz, and for most of my listening I would not need a subwoofer with any of the Exact drivers.

Between the two extremes of high and low, the Exact drivers are extremely flat, without any peaks. This is because they are used with a special servo circuit, called the EL control, that is installed between the power amplifier and the drivers. Without this circuit, these drivers would have a gradually rising response curve (somewhat) similar to Lowthers. Some people prefer the sound without this circuitry, and others like to switch back and forth depending on the music. Having listened to various models both with and without the circuitry, my personal conclusion is that the 16cm drivers with large diameter voice coils sound best without the EL control, and all the other drivers sound best with the EL control. But it is highly subjective; some other listeners shared my feelings exactly and others did not.

This brings up another point, the sound of the drivers can be shaped by many variables. They can be used with or without acoustic lenses, and the lenses can be flipped upside down for a different dispersion effect. (I usually prefer them without acoustic lenses.) The EL control has several possible settings, and there is the option of eliminating that as well. Even the enclosure port is adjustable like the zoom lens of a camera. (The port can be purchased by someone who makes his own enclosure.)

Most of the drivers are used in ported cabinets of around 40 liters volume. The 12cm drivers can also be used in a 15 liter cabinet with very good results.

I should emphasize that the drivers are actually much different from Lowther type drivers in some important respects. The range of cone movement is much greater with these drivers than with Lowthers, by a factor of 10. Lowthers are best for horn loading, and these are best for ported enclosures.

The first pair to an overseas buyer went to a gentleman in Hong Kong, just the other day, and he has not yet begun to use them. A gentleman in Singapore already has a pair on order, and a gentleman from Sweden shall soon be placing an order. The Swedish gentleman has visited Japan several times to meet with Mr. Sano. Anyone contemplating becoming the next overseas purchaser will need not only deep pockets (depending on the model), but also a great deal of patience, as the absolute shortest time to completion is about 60 days, and waits twice that long are not uncommon. Part of this is because Mr. Sano customizes each driver according to the needs of each user, and partly it is because he is a totally uncompromising perfectionist, and part of it is because he does almost everything himself, and he only has two hands.

Another bottleneck is me, since I translate messages back and forth between Mr. Sano and overseas purchasers, and I sometimes get extremely busy at my work. (I work in the head office of one of Japan's largest securities companies.)

I expect I'll get my drivers in another three months. As one who knows their sound well, I can say with confidence it will have been worth the wait.

Christopher Witmer
Tokyo

Dear Jan,

It is a passive circuit controlling a pair of concentric voice coils (the voice coil is wound using a pair of wires, thus creating a concentric dual voice coil).

I shall try to upload a simple circuit diagram. If you can see it, you know I was successful.

Christopher Witmer
Tokyo