Hi bfard
The tweeter is a Dyanaudio Esotar (unfortunately not available anymore) and the woofer was a custom design builty by Skaaning (you can buy their woofers or have them built for you, so it is almost impossible to gestimate the specs). On the back was a passive radiator which was a normal driver of it's own, or so I think- you could adjust the damping to the PR, so I suppose this was simply done with resistors in series to the VC. This is about all I do know about it, so good luck. A very ambitious project if you ask me.
Enjoy,
Deon
The tweeter is a Dyanaudio Esotar (unfortunately not available anymore) and the woofer was a custom design builty by Skaaning (you can buy their woofers or have them built for you, so it is almost impossible to gestimate the specs). On the back was a passive radiator which was a normal driver of it's own, or so I think- you could adjust the damping to the PR, so I suppose this was simply done with resistors in series to the VC. This is about all I do know about it, so good luck. A very ambitious project if you ask me.
Enjoy,
Deon
SF Extrema was a beautifull project and for me SF´s best speaker ever.
It have lameled enclosure (like Kharma speakers) , tweeter was Dynaudio Esotar D330 , bas driver vas custom Skaaning (Audio technology) 8 inch Flex unit with long gap-short coli 2 inch voice coli.
At back of speaker was B139 KEF driver that was acting as passive radiator. B139 voice coil was shunted with various value power resistors that are selected by rotari swich on back of speaker.
It acts like Qfactor adj. of bass system.
Crossover is first order design around 2KHz.
It have lameled enclosure (like Kharma speakers) , tweeter was Dynaudio Esotar D330 , bas driver vas custom Skaaning (Audio technology) 8 inch Flex unit with long gap-short coli 2 inch voice coli.
At back of speaker was B139 KEF driver that was acting as passive radiator. B139 voice coil was shunted with various value power resistors that are selected by rotari swich on back of speaker.
It acts like Qfactor adj. of bass system.
Crossover is first order design around 2KHz.
Check out this topic (Visaton-Cremona style
) on a Dutch DIY forum. Don't mind the drivers, these are Visaton. However, the cabinet building probably will provide you with sufficient ideas.
Unfortunately, the langueage is Dutch, but the generous amount of pics makes up for that.
Check this out as well:
Pics French Cremona clone project (other construction method)
However, I don't have info on original driver choice and filter setup. I know that SF uses Mundorf Supreme caps.
) on a Dutch DIY forum. Don't mind the drivers, these are Visaton. However, the cabinet building probably will provide you with sufficient ideas.
Unfortunately, the langueage is Dutch, but the generous amount of pics makes up for that.
Check this out as well:
Pics French Cremona clone project (other construction method)
However, I don't have info on original driver choice and filter setup. I know that SF uses Mundorf Supreme caps.
Grilles
fgroen - if I may do a tiny little "butt-in" here - do you have any idea what the grilles are on those clones/how they're made, etc? I didn't read the first link so if the info is there let me know; I also didn't look at all the pics on the second link. I'm thinking of doing some grilles like that on some speaks I'm planning on building next year - either vertical bars or a hexagrid screen.
Those are beautiful speakers for sure.
fgroen - if I may do a tiny little "butt-in" here - do you have any idea what the grilles are on those clones/how they're made, etc? I didn't read the first link so if the info is there let me know; I also didn't look at all the pics on the second link. I'm thinking of doing some grilles like that on some speaks I'm planning on building next year - either vertical bars or a hexagrid screen.
Those are beautiful speakers for sure.
Guys, thanks for the compliments, I will forward them to the rightful person. He's a Dutch guy like me, named Frank.
I do love the Sonus-Faber looks, but I'm currently engaged in an Avalon-like speaker. Not a clone, but my own design. When I was halfway the project Mr. Patel came up with the Isis, that uses the same speaker unit selection as my project. Difference is that the Isis has two woofers where I have one, and I started off with the Ceramic version of the tweeter where the Isis obviously has a diamond tweeter. He's such a copy cat!
Here's a pic of my project in a recent stage. (also popped up in some other threads)
As for the grilles on that French website: One of the pics shows a machined block of aluminium with little holes.
He probably glued in steel rods on both ends and fixed the blocks to the cabinet somehow. I don't know how difficult it is to remove and replace these grilles.
He CAN remove them...
I'm checking out his site a bit, but for the moment can't find more info on the Cremona's. There are only pics of the Cremona's but no link on his homepage for further info.
He's a Dutch guy like me, named Frank. I do love the Sonus-Faber looks, but I'm currently engaged in an Avalon-like speaker. Not a clone, but my own design. When I was halfway the project Mr. Patel came up with the Isis, that uses the same speaker unit selection as my project. Difference is that the Isis has two woofers where I have one, and I started off with the Ceramic version of the tweeter where the Isis obviously has a diamond tweeter. He's such a copy cat!
Here's a pic of my project in a recent stage. (also popped up in some other threads)
An externally hosted image should be here but it was not working when we last tested it.
As for the grilles on that French website: One of the pics shows a machined block of aluminium with little holes.
He probably glued in steel rods on both ends and fixed the blocks to the cabinet somehow. I don't know how difficult it is to remove and replace these grilles.
He CAN remove them...
I'm checking out his site a bit, but for the moment can't find more info on the Cremona's. There are only pics of the Cremona's but no link on his homepage for further info.
That's smart!!
I was already wondering how to get these rods so straight.
Then it's "easy". Just get the alu blocks machined somewhere. 
I just found out that the French site publishing these pics is merely a collection of designs and pics. The guy who set up the website didn't build them himself. I don't know who did build them however, it didn't say. Mayby Google Image will give some results.
I was already wondering how to get these rods so straight.
Then it's "easy".
Just get the alu blocks machined somewhere. I just found out that the French site publishing these pics is merely a collection of designs and pics. The guy who set up the website didn't build them himself. I don't know who did build them however, it didn't say. Mayby Google Image will give some results.
Hmm. Seems that the French guy was involved in developing the filters. Some other guy built the cabinets.
The filter they ended up with is not a replica of the original, but an own brew. However, it might be something of youdon't find the original drawings.
The filter they ended up with is not a replica of the original, but an own brew. However, it might be something of youdon't find the original drawings.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Sonus Faber Extrema
An externally hosted image should be here but it was not working when we last tested it.
That is beautiful work. I can appreciate the effort inviolved.
I spent a lot of time figuring out a way to replicate the Sonus Faber grill. Almost gave up and went with a standard grill cloth but decided the project needed the original design.
I found stretchable bracelet string in bulk and it worked out fine. My grill has a "V" design though with less thread density on the tweeter.
I spent a lot of time figuring out a way to replicate the Sonus Faber grill. Almost gave up and went with a standard grill cloth but decided the project needed the original design.
I found stretchable bracelet string in bulk and it worked out fine. My grill has a "V" design though with less thread density on the tweeter.
Passive Driver!
Does anybody know what are the benefits, if any, of using a passive driver with a flat diaphragm (like the KEF B139) versus a cone shaped one? The closest driver I can find instead of the KEF is Tang Band subwoofer which is a 8X12 oval driver, but has a cone shaped diaphragm ( and of course different parameters). Also when I look at some of the Extrema's photos, not all of them are using the KEF B139 as a passive driver.
Does anybody know what are the benefits, if any, of using a passive driver with a flat diaphragm (like the KEF B139) versus a cone shaped one? The closest driver I can find instead of the KEF is Tang Band subwoofer which is a 8X12 oval driver, but has a cone shaped diaphragm ( and of course different parameters). Also when I look at some of the Extrema's photos, not all of them are using the KEF B139 as a passive driver.
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