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PURIFI finally did a fully purified passive speaker design! The SPK 16 prototype is here - with a PTT tweeter

DTTOM37

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The Belgian-Danish source of audio greatness in Roskilde / Denmark have achieved to provide something to the community that many DIY speaker enthusiasts were hoping for.:
A PTT tweeter !!!

They've put that little thingy called PTT 33 tweeter - which Lars Risbo describes as:
"33mm alu hard dome with +-1 mm linear stroke, low distortion. Dome optimised for wide dispersion. Non resonant nautilus style rear chamber. demo speaker uses tweeter in 147mm waveguide optimised for constant directivity in the box. a phase plug /coherer near throat of the wave guide widens the dispersion. +-70deg beam width to 20kHz"
- into a reference design stand mount speaker named SPK 16.

The tweeter radiation pattern sows an exeptional horizontal dispersion (inbox, 1m), an achievement the PURIFI engenii seem to be proud of ;-)

PTT tweeter RP.jpg


Lars Risbo wrote me that it is crossing over around 2kz and the full crossover network was developed in-house. The F3 is 32Hz and its response is working flat into 37Hz says the press release, which is attached to the posting.

FFR in box SPK16.jpg


The SPK 16 prototype:

The standmount speaker (I'll bet it will be in PURIFI red at the Munich show!) is a 22 liter reference design, with the new PTT33 (mm) aluminum cone tweeter and the 4-Ohm PTT6.5X04-NAA woofer, feat. 2x 6.5" Passive Radiators - side mounted.

SPK 16 prototype.jpg


He has written a white paper about the prototype which will be published in time for the MHE. As I was enjoying reading it, I ask about pre-releasing the chapter 1 and 2 about the goals to reach and challenges they tried to master, which he gently agreed to.

Here are page 1 and 2 of the WP by Lars Risbo.

WP P1.jpg


WP P2.jpg


The other four chapters will be released in time for the MHE and as far as I can judge the company, they will be happy to discuss their ideas with you !

Purifi will be a the Munich High End show (Hall 1, A8 - Munich, May 18-21, 2023) and they have an open show room at Saturday afternoon in a more privative environment.
(see attached press release for more info)

The company has announced the following premieres next week.:

Munich.png

Final words come from Bruno:
“DON'T MISS THE OPPORTUNITY TO HEAR THE SPK16 DEMO WITH THE NEW AMPLIFIER GENERATION – IT’S QUITE A TREAT!
 

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  • 230508_R01-PURIFI-Audio-Munich-2023-Invitation upd.pdf
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Gotta love tweeter waveguides.
 
The Belgian-Danish source of audio greatness in Roskilde / Denmark have achieved to provide something to the community that many DIY speaker enthusiasts were hoping for.:
A PTT tweeter !!!

They've put that little thingy called PTT 33 tweeter - which Lars Risbo describes as:
"33mm alu hard dome with +-1 mm linear stroke, low distortion. Dome optimised for wide dispersion. Non resonant nautilus style rear chamber. demo speaker uses tweeter in 147mm waveguide optimised for constant directivity in the box. a phase plug /coherer near throat of the wave guide widens the dispersion. +-70deg beam width to 20kHz"
- into a reference design stand mount speaker named SPK 16.

The tweeter radiation pattern sows an exeptional horizontal dispersion (inbox, 1m), an achievement the PURIFI engenii seem to be proud of ;-)

View attachment 284370

Lars Risbo wrote me that it is crossing over around 2kz and the full crossover network was developed in-house. The F3 is 32Hz and its response is working flat into 37Hz says the press release, which is attached to the posting.

View attachment 284371

The SPK 16 prototype:

The standmount speaker (I'll bet it will be in PURIFI red at the Munich show!) is a 22 liter reference design, with the new PTT33 (mm) aluminum cone tweeter and the 4-Ohm PTT6.5X04-NAA woofer, feat. 2x 6.5" Passive Radiators - side mounted.

View attachment 284373

He has written a white paper about the prototype which will be published in time for the MHE. As I was enjoying reading it, I ask about pre-releasing the chapter 1 and 2 about the goals to reach and challenges they tried to master, which he gently agreed to.

Here are page 1 and 2 of the WP by Lars Risbo.

View attachment 284375

View attachment 284376

The other four chapters will be released in time for the MHE and as far as I can judge the company, they will be happy to discuss their ideas with you !

Purifi will be a the Munich High End show (Hall 1, A8 - Munich, May 18-21, 2023) and they have an open show room at Saturday afternoon in a more privative environment.
(see attached press release for more info)

The company has announced the following premieres next week.:

View attachment 284379
Final words come from Bruno:
“DON'T MISS THE OPPORTUNITY TO HEAR THE SPK16 DEMO WITH THE NEW AMPLIFIER GENERATION – IT’S QUITE A TREAT!
Passive? With High Power BTL amp module?
 
I wrote to Purifi and received an extremely prompt reply from Claus Purifi’s CEO, I suggested that they should make it, there could be a passive version and an active ‘modular’ version with external bits so customers could still feel they have some degree of component choice , dealers would like it ( they don’t like actives) and the amps outside would allay traditional listeners fears of vibrations in the enclosure.
I mean one of the Purifi ‘four’ has already designed a couple of decent loudspeakers!
Keith
 
Now add this tweeter to the center of the woofer, and model the woofer diaphragm to the shape of the shallow waveguide, and there is your Purifi coax! :)

Looks an awful lot like the Sointuva, doesn't it? Would be nicer if he screw heads were recessed.
Yes, I thought that too looking at the very rounded edges. Maybe Alan supplied them the box??
 
Okay I'm impressed by the drivers and design and all but also a bit skeptical about super low directivity/high dispersion all the way to 20k Hz. Now the in room response will be flat, if not enough absorbing surface is used in the room, instead of downward sloping. According to Harman findings in blind test listeners vote such speakers as too bright and have lower preference vs downward sloping.
 
Now add this tweeter to the center of the woofer, and model the woofer diaphragm to the shape of the shallow waveguide, and there is your Purifi coax! :)
Well it achieves this high dispersion thanks to that big phase plug so that's already a big problem on how to design that into a coaxial
 
Update: The complete white paper can be found now at the new designed Purifi website.
PURIFI
Very well done to Purifi. Using mathematical simulation is the best way to optimise a speaker design.

I used LEAP which is a custom crossover design software when designing Silver 5L similar to how Purifi did. Unfortunately, Leap no longer exists as software like Matlap does the job better.
 
Okay I'm impressed by the drivers and design and all but also a bit skeptical about super low directivity/high dispersion all the way to 20k Hz. Now the in room response will be flat, if not enough absorbing surface is used in the room, instead of downward sloping. According to Harman findings in blind test listeners vote such speakers as too bright and have lower preference vs downward sloping.
I thought about that as well and we definitely need to see the estimated in-room response of this speaker.
 
Now add this tweeter to the center of the woofer, and model the woofer diaphragm to the shape of the shallow waveguide, and there is your Purifi coax

A Purifi coax would be really great.

The key feature of high excursion with low distortion of the Purifi woofer isn't beneficial for such a coax due to the modulation with higher excursion.

But they can build a midrange high frequency coax (300Hz to 20kHz) with a fitting coax waveguide. Such a product might sell very well. I wonder why no driver manufacturer has developed such a package, yet??
 
But they can build a midrange high frequency coax (300Hz to 20kHz) with a fitting coax waveguide. Such a product might sell very well.
Exactly what I want.
 
Any Purifi tweeter price and availability?
 
Pre-production at the moment release perhaps at the end of the year.
Keith
 
Well it achieves this high dispersion thanks to that big phase plug so that's already a big problem on how to design that into a coaxial
Since the 8th generation of the KEF Uni-Q this is achieved on the upper treble with its tangerine waveguide.
 
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