Diatone-DBR; "Hommage a Kondo-san"

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So, I couldn´t keep myself from building these...As I have stated elsewhere, I´m really fond of the Aucharm Diatone p610 replicas. Even though I have them in my OBs I wanted to try to build something where they stood on their own, just to see what they actually could as a single driver. At first I had the thought to build the Kondo-san design as it was just to own something designed by the legend. However, I know myself - I can´t follow a recipe without adding my own twist. Furthermore, the replicas are not clones, they have different, in some respects better, parameters. Lower Fs for one. But I did glance at and let me be inspired by the Kondo design. So..calculating a normal bass reflex from those parameters I ended up with 121L (!). Big. (Huge, I would realize when I put them together) But I really like these drivers and I did want to see what they could, so I figured - if that is what you want, that´s what you are gonna get. Now I know there are different opinions about how to divide a double bass reflex, but again I glanced at Kondo´s design and decided for a ca 30/70 division. In my case 38L and 83L for first and second chamber. First chamber tuned to the drivers Fs 49.3 Hz, a 3" flared port of ca 6" lenght. Second chamber tuned to 30 Hz, 4" flared port of 10" downfiring.
So, how does it sound. Well as you can imagine, my expectations where high. It is also unavoidable that I compare with the speakers I have listened to last, my OB´s "Fait accompli" with the same Diatones + Scanspeak ringradiator tweeters and Seas 10" woofers in an aperiodic box. (the woofers that is) My conclusion; the tweeters are not neccesary, the Diatones handles the HF just fine. To my ears at least, at my age I probably only hear up to 16000 Hz, so 40000 Hz is a little bit unneccesary.
The mids are as we know, these drivers "raison d´etre" Few can compete, maybe a couple of Scanspeak mid-drivers. Though I must confess, they are a little bit more open in the open baffles - no surprise. I´m also a tiny bit disappointed that mounting the drivers from the rear of the baffles didn´t result in even better projection and render the speakers auditively invisible as I had hoped for. ( I first saw this in a version of the Hawaii 5-0 bass reflex, looked at the Diatones and realized that they where built for mounting this way, with the dense foam gasket in the mounting rim. I have also seen several speakers on Japanese sites where the drivers where mounted from behind.) Finally bass, well, the bass is actually more defined, more detailed than in my OB´s ( I think I know why - in the DBR it IS the Diatones that play the bass, in the OB´s it´s the Seas woofers and they are downfiring, which I think looses some of the definition just above where the bass goes omni-directional (?)). However, bass is a little less "fysical" in the DBR, but that might improve...The drivers being brand new out of the box, will probably need some burning in and I noticed significant improvement just after one hour of playing. I have today tested by switching from the DBR to the OBs back and forth, and the difference is marginal both when it comes to the quality/openness of the mids and bassextention. But the marginal difference is of course in both cases in the OBs favor. But I am a tough customer, nothing but the best is good enough, and these have to be some of the best single driver full range speakers around. And they should be, with that size! ;-) When they are fully burned in, I would like to find a way to measure their performance, if not so just to make sure that I´m not fooling myself for psychological reasons.
 

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So, I wasn´t totally content, after all. Now I´ve exchanged the drivers for the alnico-version and shortened the legs an inch. The legs, cause I figured if the port came a little closer to the floor there would be some slot-loading effect giving me a little bit more room-gain. And the alnicos have 20 liters more vas, so now I´m giving the box it´s run for the money (or liters). And I was indeed right. At first there wasn´t much difference, but only after like 10 hours I can only say; perfection. I don´t want anything more, it´s all there - and now also the bass.
 
Hi Bunkhokum, can I ask where you sourced these cones and maybe the price for 2 ?

I see there are 2 versions similar to yours on ebay and another site claiming to originate from same factory as Orgue cones.
One is ALNICO (the ones you now have) double the price of the other cheaper magnets model... the new "improved ones have leather surrounds vs fabric and modified paper cones for a better sound.
 
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So, first, the ferrite ones I bought on ebay, $57 a piece. The alnico ones I bought on taobao, (actually the taobaoagent buychina, $128 a piece. The alnicoversion on ebay is yet another one with cast frame departing from the original design. (those I plan to use in my next ambitious design, an open baffle with push-pull woofers in a transmissionline. And, yes, mine are the "new, improved, leather surround" etc. They are made by a taiwanese firm (I think) called Aucharm. ( and the might have made the Orgues, I´m not sure)The older version (fabric surround etc) where made by Valab, who now makes the l cao full range drivers. Anywhy, difference. Sound qualitywise I can´t tell much difference. The sellers them selves say that the difference is 100% the price and 10% the sound. Alnico is expensive nowadays. And I was really pleased with the sound as far as soundquality was concerned with the ferrite ones. Must be the best deal existing. But I wanted some more bass ( I wanted the best full range speaker ever, so...) And that´s where the alnicos came in. With a vas of 68l as opposed to 48l for the ferrites ( Qts 57 instead of 47 ) they delivered that last bit of missing bass, in this particular box-design. I´m not sure that you can say that in general, I think it is design-dependant. I should mention that the total volume of 120l (119) was calculated for the ferrites. The alnicos should have 228l (!)according to calculation, wich goes to show that numbers and math is not the only thing that matters. ( I´m quite sure I wouldn´t get any more bass if I made them bigger, I actually think that it is the combination of the a little to great vas and the not quite big enough space that interacts in this lucky way. And the quality of the bass, I sould add is tight, focused, detailed and musical, not boomy or diffuse or anything like that. Hope this answered the questions.
 
Thanks, if you have the email contact of the Alnico guy that would be great...I think that Tao site is 100% Chinese (and why not its aimed at Chinese) but I could not figure out their strange pricing today 780 Yen (?) etc for FR drivers....

Edit : aha just found buychina from your post....thought it was taobao site you got them directly...
 
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Buy China Wholesale from Taobao Agent with Free Shipping - BuyChina.com That´s where I bought them. Search the site for diatone, and you´ll find at least a couple of sellers. It´s not the fastest way to shop, but.. For instance, paying with card didn´t work (for me) so I had to make a banktransfer, which took some time. On the other hand there is a lot of interesting things on the site, I bought a single-ended 807 amp for $330 usd, that I´m really pleased with. But it took like 2 months to get it.
 
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