# New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REVIEW)



## bbfoto (Aug 28, 2005)

*New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REVIEW)*

*Purifi Audio 6.5" PTT6.5W04-01A Midwoofer*

A brand new Long Stroke 6.5" Midwoofer manufactured in Denmark with some Very Interesting and Unique Technology (including a wild-looking surround and a 4-layer voice coil) that is designed to not compromise the midrange detail and coherency.

The impedance curve, FR, and HD plots alone give you a good picture of its potential performance. 

All of this information *AND WAY MORE* is taken directly from the HiFi Compass website review.

To start, just read the list of people involved in forming the company and their credentials. 

...But there is A LOT more in-depth information on the web Link below:

https://hificompass.com/en/reviews/purifi-audio-ptt65w04-01a-midwoofer


*As a side note: Pricing would be quite attractive if we were to put together a Group Buy! See below.* :surprised:

*Lars Risbo on the unconventional 39mm Diameter, 24mm Tall, 4-LAYER Voice Coil:*

"The 24mm Ø39mm 4 layer coil is responsible for the higher moving mass. It adds about 10g compared to a shorter 2-layer coil of a typical medium stroke 6.5” midwoofer.

The paper cone is actually lighter than typical polypropylene or aluminum cones. The larger coil gives the benefit of high Bl and power handling which enables operation in small sealed boxes with use of lots of bass extension EQ.

Since we also achieve very low coil inductance Le then the midrange response is uncompromised, i.e., the driver is still very ‘fast’ despite its higher moving mass.

It’s like sportscars: the top speed is set by its power and friction/drag not by its mass (a Bugatti Chiron is about 2 tons of mass yet extremely fast). However, a bigger motor is more heavy – the same applies for speakers."


So, here are the key highlights from the HiFi Compass Review of the PURIFI PTT6.5W04-01A midwoofer:


Modest Sensitivity - 88.2 dB/2.83 Volt*1m
Huge Linear Voice Coil Excursion - real 10mm each direction.
Real working PURIFI Neutral Surround technology.
Hard cellulose based fiber-filled cone having no significant breakups.
Very Even Sound Pressure Frequency Response (On-/Off-Axis).
VERY Low Harmonic Distortion.
Very Low Motor Air Noise at low frequencies (unlike Scanspeak 18wu).
Excellent Intermodulation Distortion.
Very Good Craftsmanship/Build Quality.
Excellent Impedance Frequency Response.
Can be used in a 2-way loudspeaker up to the 3kHz crossover point.
Except for the high mass of the moving system (26.8 grams), there is nothing more to complain about (but see Lars Risbo's comment regarding that).
 
You can get more information about the measurement results here...

https://hificompass.com/en/speakers/measurements/purifi/purifi-ptt65w04-01a



*PRICING: (as of November, 2019)*

Lars Risbo: We are working hard on getting the web shop operating - hopefully within a few weeks. This is mostly for DIY'ers. Currenty, the planned prices are:

DIY pricing:

$390 @ 1-2
$334 @ 3-4
$279 @ 5-6
*$230 @ 7-9*
+VAT (depending on country)

OEM prices are on quotation.


The FULL REVIEW is EXCELLENT and incredibly detailed. It includes much more information, including more independent test measurements, and comparisons to other top-tier drivers.

It's amazing to me how far traditional loudspeaker transducer design can still be pushed, and the incredible performance that can be attained.


The manufacturer-supplied* Data Sheets* and some *Photos* of the driver:


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## dcfis (Sep 9, 2016)

Looks awesome really


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## -Kyle- (Feb 5, 2009)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Is that price for a single driver or for a pair?


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## Dan750iL (Jan 16, 2016)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Freaky looking surround but very cool.


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



-Kyle- said:


> Is that price for a single driver or for a pair?


Single driver, I believe.

Compare to the  *ScanSpeak Illuminator 18WU/4741T-00 7" Midwoofer - $337.60 @ Madisound*

*Audiofrog GB60 - $899/pair @ Crutchfield*

...or the (also Danish-made) Dynaudio Esotar2 E650 6.5" Midwoofers.


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Dan750iL said:


> Freaky looking surround but very cool.


I agree. It doesn't really look like it would keep the cone linear at all, but it obviously must! Crazy chit, but I'm liking what I see.

Typically when you have high Xmax drivers, you will naturally gain more output in the low frequencies, but that output usually will not be as clean or "fast" sounding because that extra cone travel also increases stored energy, i.e. more time before the woofer cone comes to rest after receiving the input signal.

So I'm really interested to hear these in terms of their low-end definition at moderate to high levels, in addition to their overall FR and clarity.

It's a great time for speaker evolution and revolution. I'm also liking the concept with the innovation Pioneer has developed with their two side-driven motors connected to a folding-hinge "surround" and square or rectangular diaphragm. Other than the slim car audio subwoofer seen in the video below, I don't know if this technology has been put into actual production. See the video below regarding Pioneer's "Horizontal-Vertical Transforming" technology (HVT) at around 1:54


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## Jscoyne2 (Oct 29, 2014)

*Re: New 6.5&quot; 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS &amp; REV*

Isn't like 30-50% of surround supposed to add to cone area. With a surround like that. I'd think you'd have different response at seat by simply turning the driver 90 degrees on the same baffle plane.

Sent from my XT1710-02 using Tapatalk


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

The design of the surround is to essentially make it disappear, so that it will not add any
breakup resonances at the cone/surround junction. And it's more like a 7" driver than a 6.5",
so that probably makes up for any losses from the "invisible" or "missing" surround.

It would be interesting to test the driver rotated 90° in the baffle, though both the
manufacturer's and independent frequency response measurements in the review don't
show any detrimental off-axis response IMO. And sensitivity remains relatively high, so
I don't think the loss of the surround's usual cone area contributions are significant.

The height of surround at any point around the perimeter is less than the wavelength
any of the higher frequencies that the midwoofer will typically be crossed over at, so
frequencies within its recommended passband will not be obstructed by it or interfered
with in any significant manner.

Frequency - Wavelength - Period Chart

Read the notes below the chart for some interesting facts, such as, "The Boesendorfer
Model 290 Piano has 9 extra sub-bass notes down to the low C (C0) at 16.4 Hz". And
"The 'middle C' on a piano has a fundamental of 261.6Hz, but also various combinations of
both even-numbered and odd-numbered harmonics, typically all the way up to 16,744 Hz.
That's the 64th harmonic!"


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## JMikeK (Jan 2, 2019)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

My god the measurements are beautiful. I've heard people claim they don't need a sub, but with these, it may be getting pretty close (and they wouldn't embarrass themselves in a two-way system either). Very impressive!


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



JMikeK said:


> My god the measurements are beautiful. I've heard people claim theydon't need a sub,
> but with these, it may be getting pretty close (and they wouldn't embarrass themselves in a two-way system either). Very impressive!


Agreed. Unless I'm missing something, the measurements point to almost unobtainium levels
of performance.


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## Bayboy (Dec 29, 2010)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Hmmmm.... 

Man & Machine... Power Extreme!


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## Electrodynamic (Nov 27, 2007)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Very cool design. I dig the surround.  

Long'ish coil but layered accordingly. The entire coil isn't 4 layers. LMS, hence the slightly lower sensitivity. Neat to see it being used though. 

Speaker connections will cause this forum's head to explode though.


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## seafish (Aug 1, 2012)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

I'm in on a group buy after production has actually started.


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## Hillbilly SQ (Jan 26, 2007)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Electrodynamic said:


> Very cool design. I dig the surround.
> 
> Long'ish coil but layered accordingly. The entire coil isn't 4 layers. LMS, hence the slightly lower sensitivity. Neat to see it being used though.
> 
> Speaker connections will cause this forum's head to explode though.


What's wrong with the terminals? Do the cool kids not use speakers with spade connections anymore?:laugh:


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## Gump_Runner (Aug 2, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Sweet! That surround is wicked.


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Electrodynamic said:


> ...
> 
> Speaker connections will cause this forum's head to explode though.


Haha. I'm one that much prefers simple spade terminals. I think any other type of terminal is unnecessary, except for maybe just having pre-installed pigtails on tweeters, or also on traditional, largish subwoofers. Most other terminals are unnecessarily bulky and just get in the way when mounting, especially spring-push terminals on drivers under 10".

I've never experienced a problem if the proper high-quality spade connectors are used. But I typically solder pigtails directly to the speaker and use the XT60 or the small Anderson Power Pole connectors to enable quick-disconnect if and when needed.

I can see where the general public equate shiny/bulky/fancy terminals to mean that the speakers themselves must be "high end", but I look past that and look at the actual design and measured performance of the driver. 

Enough of my derail...back to the topic.


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## Hillbilly SQ (Jan 26, 2007)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



bbfoto said:


> Haha. I'm one that much prefers simple spade terminals. I think any other type of terminal is unnecessary, except for maybe just having pre-installed pigtails on tweeters, or also on traditional, largish subwoofers. Most other terminals are unnecessarily bulky and just get in the way when mounting, especially spring-push terminals on drivers under 10".
> 
> I've never experienced a problem if the proper high-quality spade connectors are used. But I typically solder pigtails directly to the speaker and use the XT60 or the small Anderson Power Pole connectors to enable quick-disconnect if and when needed.
> 
> ...


Let's not forget about push terminals on tweeters:laugh:Give me a pre-installed pigtail any day of the week on those.


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## Electrodynamic (Nov 27, 2007)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Hillbilly SQ said:


> What's wrong with the terminals? Do the cool kids not use speakers with spade connections anymore?:laugh:


You were around during the TM65 mkI days weren't you? Those had spade terminals and people went berserk on here.


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## Mad Scientist (Feb 12, 2017)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

It's somewhat surprising the tinsel leads aren't 180 degrees from each other. Electrodynamic can probably offer some insight as to what impact this would have on its performance. Just curious.

Add me to the group buy list. Assuming specs are even remotely close to the actual performance of the driver, then I can't justify not testing them.


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## Focused4door (Aug 15, 2015)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



JMikeK said:


> My god the measurements are beautiful. I've heard people claim they don't need a sub, but with these, it may be getting pretty close (and they wouldn't embarrass themselves in a two-way system either). Very impressive!


I doubt I would be happy without a sub based on modeling IB in WinIsd 

Modeling it in a QB5 box it is a beast for midbass though


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## beak81champ (Oct 2, 2015)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

I would like to be on that list for a pair as well...


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## DavidRam (Nov 2, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Who's dental impressions are those in the surround?? Lol




Seriously, though, very interesting stuff and thanks for posting!


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## Electrodynamic (Nov 27, 2007)

Mad Scientist said:


> It's somewhat surprising the tinsel leads aren't 180 degrees from each other. Electrodynamic can probably offer some insight as to what impact this would have on its performance. Just curious.
> 
> Add me to the group buy list. Assuming specs are even remotely close to the actual performance of the driver, then I can't justify not testing them.


Normally an asymmetrical lead profile on a spider leads to coil rocking from the compliance stiffness (or lack thereof, depending on how you define it) on one side of the spider versus the other side. But this particular coil geometry immediately allows for a loose gap and low sensitivity being LMS. And the upper frequency limitation is dictated by inductance rather than cone breakup. It's at a nice point of 3k'ish which will suffice for many applications.


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Electrodynamic said:


> Normally an asymmetrical lead profile on a spider leads to coil rocking from the compliance stiffness (or lack thereof, depending on how you define it) on one side of the spider versus the other side. But this particular coil geometry immediately allows for a loose gap and low sensitivity being LMS. And the upper frequency limitation is dictated by inductance rather than cone breakup. It's at a nice point of 3k'ish which will suffice for many applications.


Thanks for that, and agreed on that last bit.

My _only_ nitpick with this driver as it stands is that it's not TM65-MKIII shallow.  It has a substantial magnet diameter + thickness, combined with a fairly deep top-mount depth. I guess that you can't always cheat when it comes to physics.

But a more compact Neo motor would have been an advantage for us car audio DIY'ers (if it is even possible with this motor/coil topology)?

And I'm not sure of the science or implications regarding the _magnetic hysterisis_ properties between ferrite & neodymium? Read the full review in the provided link, but "Low Magnetic Hysterisis Distortion" is listed as a key bullet point.

Of, course a Neo motor would have raised the end cost and is a non-issue for the Home DIY crowd which I'm also interested in using this driver.

But for this level of performance I'm probably more willing to compromise and "cut metal" or design & build custom kick panels and/or door panel trim+grilles if required.


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## ToNasty (Jan 23, 2013)

beak81champ said:


> I would like to be on that list for a pair as well...


I wouldn't mind signing up for a pair myself


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



DavidRam said:


> Who's dental impressions are those in the surround?? Lol
> 
> Seriously, though, very interesting stuff and thanks for posting!


Haha...I was trying to figure out what the shape of that surround reminded me of? !#&!...Bingo!


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## Bayboy (Dec 29, 2010)

*Re: New 6.5&quot; 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS &amp; REV*

Obvious attributes aside, what is it about this driver that makes it attractive for car audio? We're talking about door locations where the driver will pretty much be infinite baffle. That said, it's stiffness isn't what I would call ideal nor is its electromechanical factors unless you're willing to do quite a bit of work to dial it in as well as bracing the hell out skins & panels, but even then, excursion capabilities could be negated by natural roll-off which doesn't come down as low as many claim to want. 

Man & Machine... Power Extreme!


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## ToNasty (Jan 23, 2013)

Bayboy said:


> Obvious attributes aside, what is it about this driver that makes it attractive for car audio? We're talking about door locations where the driver will pretty much be infinite baffle. That said, it's stiffness isn't what I would call ideal nor is its electromechanical factors unless you're willing to do quite a bit of work to dial it in as well as bracing the hell out skins & panels, but even then, excursion capabilities could be negated by natural roll-off which doesn't come down as low as many claim to want.
> 
> Man & Machine... Power Extreme!


To me, just because it's new and looks neat. I'm all for trying to make anything work


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## Bayboy (Dec 29, 2010)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



ToNasty said:


> To me, just because it's new and looks neat. I'm all for trying to make anything work


I get that, honestly. I can include myself in the bunch that has experimented with unpopular drivers in the name of sound science. 

However, from my learnings this driver doesn't seem much of an advantage over others in its category except more excursion which isn't all that if a natural lift in lower response and a motor conducive to a well controlled & desirable response in infinite baffle is at hand. Most drivers as such are still limited to around a 100hz roll-off and will require some bottom end boost 160hz & down as well as cutting in the 200-300hz range. Perhaps the ramping up of excursion to do so will be remedied by such a long xmax. Still, drivers and relative issues such as the first version TM65 come to mind. 

Man & Machine... Power Extreme!


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## Hillbilly SQ (Jan 26, 2007)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

From the outside looking in I see a potential winner for a home audio driver but I'm with a couple others in saying nothing really sticks out about it being that great of a car audio driver if just throwing IB in a door and hoping for the best. And the mounting depth is insane. I do think these would be great with something like an SB29 or one of the Illuminator tweeters and then a really low distortion sub in a home 2.1ch setup and plenty of good clean power.


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## rton20s (Feb 14, 2011)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Wow. Just read through the HiFi Compass article and reviewed the data on Purifi's site. This seems like a very impressive driver indeed!

However, I'm on the same page as other who have stated reservations for automotive use. At least when it comes to a typical door install. Now... build your set of kicks or door enclosures of appropriate volume and you'll likely have a big winner on your hands. I still wouldn't run them without a subwoofer in a car. But for those that feel like they need to cross their mids really low (<60Hz) these might be the ticket.


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## Bayboy (Dec 29, 2010)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Unfortunate as it is (for car audio enthusiasts), I think it's probably best being used what it's designed for.... home audio. That's unless it's attributes align well with a particular install. I have yet to see or try any modeling with this driver including cabin effects if applicable, but the numbers tells me even in small sealed pods it may not look that great. Of course I'm merely referring to F3 which most consider in a driver of such size. In the likes of drivers such as the Satori which is great if you don't mind the 100hz or so limit, then perhaps a tiny bit more output can be had before reaching mechanical limits. 

Man & Machine... Power Extreme!


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## Gump_Runner (Aug 2, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Not withstanding it's performance, anytime someone finds a new "raw driver" I get excited. I miss the days when DIYMA was more focused on this type of stuff.


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## 6262ms3 (Feb 27, 2008)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



Gump_Runner said:


> Not withstanding it's performance, anytime someone finds a new "raw driver" I get excited. I miss the days when DIYMA was more focused on this type of stuff.


Agreed, it was super-fun reading about everyone's experiments and trying-out different raw drivers for yourself. That said, if you're patient-enough to wait for the right sales, any half-decent car-specific components with a DSP makes getting good results pretty damn easy at a reasonable cost these days.


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## JCsAudio (Jun 16, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & R*

I also agree with it being noted that this driver seems to be not ideal for infinite baffle/car door use although for anything else it seems fantastic.. The Thiele Small parameters just don’t lend themselves to being installed in a car door. It’s also got a paper cone (assuming untreated for moisture) and exposed voice coil which are things not ideal for the potential wet environment of a car door. 

I’m starting to think high end car audio drivers are expensive because they are low volume and hard to make for the given environment they will be exposed to. Finding a raw driver on the cheap that can rival top performing purpose built high end car audio specific drivers is like trying to find a real Sasquatch. I hear stories that they exist but have never actually seen one myself nor is there undisputable conclusive evidence they actually exist. :laugh:


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## bbfoto (Aug 28, 2005)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*



rton20s said:


> Wow. Just read through the HiFi Compass article and reviewed the data on Purifi's site. This seems like a very impressive driver indeed!
> 
> However, I'm on the same page as other who have stated reservations for automotive use. At least when it comes to a typical door install. *Now... build your set of kicks or door enclosures of appropriate volume and you'll likely have a big winner on your hands.* I still wouldn't run them without a subwoofer in a car. But for those that feel like they need to cross their mids really low (<60Hz) these might be the ticket.


^THIS.

I'll admit that I look at most DIY drivers now with a bias towards home audio and studio monitor use, so there's that.

But for car audio implementation, I come from the perspective that I don't really like to use door locations for midbass in the first place, unless they can be put into small-to-medium sealed enclosures like Gary Summers' Benz and a few others here. You CAN do that with these, and without needing a huge, round speaker grille that takes up 1/3rd of the door panel. 

YES, that is A LOT of custom fabrication to have to build. But IMO it's already a chit-ton of work to treat your doors and door panels to insanely heavy amounts to where they are nearly unrecognizable in order to get really good performance from a beastly IB midbass in the doors. And it still won't be perfect...you'll still have resonance and tactile feeback issues that aren't ideal, and rattle the window to death. IME, while it can work, it's just not the ideal location if you're looking for uncompromised midbass output.

So IMO, for the amount of work to get door IB installs to a "workable" level, you might as well go with custom sealed enclosures in the doors which will mitigate 90% of the problems of having monster IB midbass drivers in your doors.

If you are creative, you can usually do this with less work than you think (vehicle-dependent, of course). You then also don't have to worry about the elements damaging the drivers in any way, or having the actual IB "enclosure" properties change when you roll down your windows.


My preferred location for midbass is still the kickpanels. Generally better pathlengths for phase and time, and usually much better corner-loading...so more output with less boost. Actually, you will usually need a few substantial cuts to even out midbass response...so better efficiency/less power required.

Again, these Purifi drivers can be put in really small sealed enclosures. You don't have to cut metal, or at least you won't need to open the car up to the outside world, which again compromises both the vehicle and the drivers to the elements. If it's a show car, fine, no issues. But if you need it to be a road-worthy vehicle, I'm not as quick to vent to the outside or even frame rails.

Sure these drivers are large and deep, but nearly all of the typical 8" or larger midbass drivers that people normally install in their kickpanels are just as deep or will take up more real estate overall due to baffle area to install there. You can also flush these into the sides of the kickpanels and build the sealed enclosures within the front fenders from the outside in a lot of vehicles. Not very many vehicles have enough flat area in the kickpanels to handle 8" or larger drivers mounted in this orientation.


One of the key things that Lars states in the review is that they can be put in extremely small sealed enclosures and still have plenty of usable excursion to boost the low end response with no ill effects. That is one of the design decisions they consciously made when developing this driver.

I don't know if you guys remember, but that was what you needed to do and could easily accomplish with the "old" JBL GTi-660 midwoofers! They had plenty of excursion to let you boost the low end response, and they performed amazingly well doing so. Otherwise, you would be a bit underwhelmed with their midbass performance while the midrange was fantastic.

Luckily, Andy fixed that problem with the next iteration of that midwoofer...i.e. the Audiofrog GB60. But that driver is even more expensive now than when it was first released.  It does have the advantage of being a moderately shallow driver with a small magnet, making typical car door installations much easier. And it also is made to withstand the harsh environment within typical car doors, so there's that. But you got to pay to play.

Don't get me wrong, I am using the GB60 and other Audiofrog GB & GS drivers in my installs...they are amazing. But Got [email protected], while I know it ain't right to think this way, it's still a hard pill to swallow spending that much coin for a Made in China product. I know, I know...all that really matters is the performance, and in that regard they surely do not disappoint.


Anyhow... Regardless of how or where you might use this new Purifi driver, it's performance is absolutely Next Level, and that's what piqued my interest. Very few drivers, if any at this point, can match it (at least on paper for now) at ANY price. And just remember that there are no rules or regulations holding Purifi back from designing and releasing a similar driver made specifically for IB or open-baffle use in the future. 

Oh, and they _will_ be coming out with a high-end tweeter and other drivers to pair with this little gem in the not-too-distant future.


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## JCsAudio (Jun 16, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Bbfoto, I applaud your enthusiasm. You make some great points. I’m going to keep an eye on this company, especially if they come out with high quality low distortion tweeters and midrange drivers for a decent price.


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## JCsAudio (Jun 16, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Read the Purifi tech article on distortion and how the surround can easily make up 20% of the radiating surface. I wouldn’t have thought that it could be that much. There is no data to back it up so I have to assume it’s true but interesting the least. 

https://www.purifi-audio.com/wp-con...The-Sound-That-Dare-Not-Speak-Its-Name-r2.pdf

https://www.purifi-audio.com/tech/


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## Jscoyne2 (Oct 29, 2014)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Put your hand on a surround when your speaker is playing and run your finger on the outside of it inwards. The outside of the surround will be dead still until you get about 50-30% in and you'll start to feel vibration

Sent from my XT1710-02 using Tapatalk


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## Bayboy (Dec 29, 2010)

*Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*

Part of the surround being included in what moves air is pretty much basics. Vance Dickason's books are good reads for the fundamentals. 

Man & Machine... Power Extreme!


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## bbfoto (Aug 28, 2005)

seafish said:


> *Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*
> 
> I'm in on a group buy after production has actually started.





Mad Scientist said:


> *Re: New 6.5" 10mm+ Xmax RAW Driver: Purifi Audio PTT6.5W04-01A Midwoofer (SPECS & REV*
> 
> It's somewhat surprising the tinsel leads aren't 180 degrees from each other. Electrodynamic can probably offer some insight as to what impact this would have on its performance. Just curious.
> 
> Add me to the group buy list. Assuming specs are even remotely close to the actual performance of the driver, then I can't justify not testing them.



I plan to order a pair of these in the the next few weeks. Let me know if you guys are serious about ordering these??? There would be a significant savings in per unit cost, especially if we can get 8 in the order. But even ordering 6-7 is a worthwhile price break. See the link for current quantity pricing. It is listed in Danish Krone so just convert to USD. Note that the exchange rate may fluctuate a bit by the time we actually place our order, so the cost could be a bit more or less at that time.

Purifi PTT6.5W04-01A Online Shop

Let me know if anyone else is interested in a Group Buy? I'm not going to float or carry more than the cost of 4 of these, so I would need your commitment and cash in-hand before I place the quantity order @ Purifi. I will need to add ~$20 for shipping a pair to you once I receive them. I am located in Southern California.


And Claus Neesgaard at Purifi got back to me recently regarding their new 4" midrange (also with +/-10mm linear Xmax)! He said they will be posting the complete final measurements in a few weeks and the drivers will begin final production shortly after...so availability in a 30-45 days or so.

Purifi PTT4-0W04 4" Midrange Driver Preliminary Specs


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## Theslaking (Oct 8, 2013)

I'm replying because I'm interested. Not committing. I would definitely need to build an enclosure. We'll see if that's worth it to me. 

My favorite sub of all time by TC Sounds used the variable coil. It definitely works but makes it power hungry.


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## seafish (Aug 1, 2012)

Sorry ... due to current financial constraints I will need to pass for now.

That said, VERY interested in learning what you think of these.


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## bbfoto (Aug 28, 2005)

seafish said:


> Sorry ... due to current financial constraints I will need to pass for now.
> 
> That said, VERY interested in learning what you think of these.


No worries. Thanks for the prompt reply. It will be a while before I get around to actually testing these but I will be sure to post my thoughts here.


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## Mad Scientist (Feb 12, 2017)

bbfoto said:


> I plan to order a pair of these in the the next few weeks. Let me know if you guys are serious about ordering these??? There would be a significant savings in per unit cost, especially if we can get 8 in the order. But even ordering 6-7 is a worthwhile price break. See the link for current quantity pricing. It is listed in Danish Krone so just convert to USD. Note that the exchange rate may fluctuate a bit by the time we actually place our order, so the cost could be a bit more or less at that time.
> 
> Purifi PTT6.5W04-01A Online Shop
> 
> ...


You may include me in a group buy for a pair of 6.5's and a pair of 4's. I may up the order to 2 pairs of 6.5's, but for now, I'll commit to just one. I'm in no hurry, so I wouldn't mind waiting for the 4's to release before ordering everything in full. Since my goal is to build a full enclosure into my doors, the 6.5's are an ideal application for that purpose. I'd prefer the sensitivity of these drivers to be higher, but I understand the constraints on why they aren't. 

As for payment, give me a rough idea when you need it, and I'll send funds your way. 

Any updates regarding a tweeter from them and approximately when it will release? I'd probably be in for a pair of them as well.


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## rton20s (Feb 14, 2011)

I'm not in for the group buy, but I wasn't aware of the 4" model. Very interested in seeing what the complete specs look like as those get finalized. I could see those potentially replacing 5" drivers I currently have on my dash. IF they fit.


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## ErinH (Feb 14, 2007)

Billy,
The guy who runs this site is a fellow who has been helping me out with binaural recordings. I thought you might be interested in his review of the 6.5" Purifi driver used in a bookshelf here:








Purifi PTT6.5 Woofer and 1ET400A Amplifier Technology Review


I enjoy reviewing innovative loudspeakers like the Dutch and Dutch 8c and the Kii THREE. I also spend time on diyAudio’s loudspeaker forums looking at what to build next or modify what I have, essentially looking for the “next big thing.” I noticed Purifi’s woofer getting good reviews on diyAudio...




audiophilestyle.com


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## seafish (Aug 1, 2012)

BBfoto,

will you please clarify if pricing in the first post is per driver or per pair of drivers.


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## Theslaking (Oct 8, 2013)

That review is great but the specs kinda lead to that. What about in a door IB or very small sealed?


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## Mad Scientist (Feb 12, 2017)

seafish said:


> BBfoto,
> 
> will you please clarify if pricing in the first post is per driver or per pair of drivers.


Pricing is tiered based off the quantity being ordered, but for a single 6.5" driver, Purifi lists DKK2,329.00 as the This translates to $347.50 USD at the time of this posting using XE.com currency converter (this is the same converter eBay uses as well).

As mentioned previously, please note that currency rates fluctuate by the minute. 









PTT6.5X0z-NFA-01 - PURIFI


6.5" Extended Stroke Driver with Ultra Low Distortion ORDER INFORMATION: Note that this product is made-to-order. Expect approximately 4 weeks delivery time depending on quantity.




purifi-audio.com


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## Mad Scientist (Feb 12, 2017)

bbfoto,

I noticed the pricing on Purifi's site list DKK 2329.00 as the price regardless of VAT or not. Typically, customers within the EU have roughly a 20-25% markup due to VAT being added to the cost of goods. However, since we're US customers, the shipment would be an export, and exports are exempt of VAT fees. Assuming these ship from Denmark, the cost for non-VAT customers should be less than the advertised DKK 2329.00 by default. If these are shipping from a USA distributor to USA customers, then I understand why pricing could be the same. 

It's probably worth asking Purifi if DKK 2329.00 is the rate for USA customers, or if they can be shipped at a reduced price due to no VAT being applied.


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## minbari (Mar 3, 2011)

interesting. but with an 85db 1w/m. if you can find another driver that is 3-4 db more efficient then you wont need that crazy xmax.


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## bbfoto (Aug 28, 2005)

minbari said:


> interesting. but with an 85db 1w/m. if you can find another driver that is 3-4 db more efficient then you wont need that crazy xmax.


.

True, but will that other driver exhibit the purported "unusually clean & realistic" output or response of the Purifi driver?

According to the Purifi's tested measurements in comparison to most existing drivers on the market, there will be other tradeoffs or compromises with that other driver. Efficiency is just one.

I realize that this is not a driver for "everyone". Like any driver, it has unique properties & specs that make it suitable only for particular applications. It is not "one driver to rule them all".


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## Mad Scientist (Feb 12, 2017)

minbari said:


> interesting. but with an 85db 1w/m. if you can find another driver that is 3-4 db more efficient then you wont need that crazy xmax.


^ Spot on. Anyone considering the Purifi's is likely going to compare to *Scanspeak Illuminator 18WU/4747T-00* and layer the models.


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## rton20s (Feb 14, 2011)

Mad Scientist said:


> ^ Spot on. Anyone considering the Purifi's is likely going to compare to *Scanspeak Illuminator 18WU/4747T-00* and layer the models.


Compared to the 18WU, yes for a pair your down about 3dB when driven to their limit at about the lowest possible crossover in an "ideal" (0.707 Qtc) enclosure. How often are you really driving your system at 113-116dB through the midrange? (I can tell you that from my own experience in my own car, that is LOUD. Potentially concert level loud.)

If efficiency is where Purifi had to sacrifice for all of the other performance benefits (distortion reduction, excursion, etc), I can understand why they made that choice. Especially when their other debut product is a high power, ultra low distortion amplifier. With either one of these drivers at typical listening levels you're talking about pretty moderate power and nowhere near their limits, so it makes sense that all of the other aspects of the design take priority over efficiency.


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## bbfoto (Aug 28, 2005)

ErinH said:


> Billy,
> The guy who runs this site is a fellow who has been helping me out with binaural recordings. I thought you might be interested in his review of the 6.5" Purifi driver used in a bookshelf here:
> 
> 
> ...



Thanks Erin.

Ya know, I had actually read that article by Mitch when I had first posted here, but then neglected to include it here. It does well to describe and illustrate the advantages of this new driver's technology and how it might be implemented.

It's good to know that you've got blokes like Mitch to bounce your ideas off of. 

I am very interested in Purifi's amplifier modules and technology as well. There is at least one commercial offering that is using them. Expensive, as expected...

Nord Acoustics UK - Purifi 1ET400A Power Amplifiers

But it seems that it wouldn't be too difficult to put together your own DIY amp using the available modules.

Again, it's a really great time to be an audio enthusiast.


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## seafish (Aug 1, 2012)

Erin, if you ever decide you might want to perform a testing and/or listening comparison of these versus the SI TM65mk1 (XBL low distortion motor, 9mm Xmax, 89db sens, Fs 44hz) ... lemme know and I can provide you a pair of the TM65 for that purpose.


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## bbfoto (Aug 28, 2005)

I've received PMs from a few members here. It seems that several people would like to wait for the 4" driver to be available as well, myself included.

Given that, it will likely be at least another month before the 4" is available. I'm in no rush for either driver, so I'm fine with waiting. Of course, pricing and final specs for that driver have yet to be disclosed, so that will be a future consideration.

The final price will also depend on the exchange rate at the time we place the order. It will fluctuate daily a bit, but hopefully not too much to our disadvantage by the time we order.

As requested, I am checking into the pricing in regards to the European VAT. Logic says that we in the U.S. should be exempt from the VAT, and therefore our pricing should be lower. But I'll wait for Claus' response before assuming further.

So unfortunately, I can't possibly know the final pricing at this time. Just a ballpark guess from what is known regarding current pricing just on the 6.5" driver.

And just for further clarification, the pricing is per individual driver, and not for a pair.

I don't think that there will be any additional quantity discount for purchasing both the 4" & 6.5'' drivers at the same time, but I will inquire about this. If you would like the 4" driver, let me know?

If there is no additional discount for both drivers, we could move forward with a group buy now for the 6.5'' and deal with the 4" when we have more info on specs & pricing.


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## E.Murray (Jan 8, 2016)

This is excellent timing. I'm a loudspeaker engineer with Dolby and have my own anechoic chamber and Klippel. Lately, I (on my weekends) have been measuring my stash of 6.5" drivers just for fun. I've measured some L6SE, Rainbow Profi, SI TM65, PHD 6.1FB and Peerless (and two others which my brain won't recall at the moment...). One thing that was surprising was the asymmetry in all of them in the Klippel large signal measurement. The cheaper drivers (Peerless SLS, for example) were definitely worse than something fancy like the HAT. But even the higher-end stuff wasn't as great as I expected. See the below (Peerless is first set).



















When I saw the plots on the first page, then, I was blown away. If they are really that linear and symmetric, these have the potential to sound incredibly clean. I'm really tempted to order one (thanks, company card!) to see if it really is as amazing as it looks. And, if so, if the on-paper performance plays out in real life. I just completed a pair of .26 cf ported pods in my car and earlier today bought 2 different drivers to try in them (a Dayton RSS210 and Tang Band W8-1363SB) in addition to two I already have. Both of the drivers I ordered, by the way, model significantly better than this Purifi (though, to be fair, they are 8"). Using all that fancy excursion still puts me 2-3dB down at 50Hz from the Dayton or Tang Band (no replacement for displacement... and efficiency). Although I have a feeling (based on the data here) that the Purifi would sound better down there. My plan is to run the enclosures in the anechoic chamber with 4 different drivers to see what happens and choose the best ones for me. Might be worth giving these a shot. Anybody want to let me borrow one... Thanks bbfoto for drawing my attention to these.


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## Mad Scientist (Feb 12, 2017)

E. Murray,

Perhaps there are measurements somewhere, but I haven't seen them for Audio Development drivers as a whole, and I would be curious to see how they perform just as a data point.

Here on the forum, the 8inch AD SW800 receives a lot of praise, and if you have the time, I can loan you one for testing to see how it stacks up. Let me know.


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## bbfoto (Aug 28, 2005)

Here is Claus Neesgaard's email reply regarding VAT, Quantity Discounts for ordering both the 6.5" & 4" at the same time and other drivers they are working on. 

"Hi Billy,

I’ve recently become aware that our website apparently pulls country information from the IP address and will set VAT accordingly. So, as in your case, for USA VAT=0% and thus the incl. and excl. VAT price appears the same. I acknowledge that this is a bit confusing and we probably need to change how pricing is presented moving forward.

In any case, an order place from and delivered to USA won’t include Danish VAT.

At this point there won’t be any benefits in ordering the 6.5” and 4” at the same time. But ping me again before you place order on the 4” and I’ll see what I can do at that time.

With regard to your tweeter/subwoofer question: we do have several new drivers on the roadmap for 2020 ? . We’ll put some preview data on our website as information becomes available. As example, we hope to present data on an 8” version before summer.

Related to the AMT21CM2.1 specifically: in our SPK demo system the AMT actually became the limiting factor distortion-wise, so we ended up increasing the cross-over from initially 2.5KHz to now 3.2KHz with a quite substantial sonic improvement as result. So, the performance of SPK5 system is very good indeed and it receives fantastic reviews/feedback.

However, as a transducer company we will continue our focus on improving performance across the entire frequency range – and from that perspective we don’t necessarily consider the AMT “as good as it gets”.

Best regards,

Claus"


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## bbfoto (Aug 28, 2005)

Hey guys, sorry, I've kind of put these on the back burner with everything else that is going on currently.

However, the Purifi 4" midrange is now available so my interest is somewhat renewed.

Unfortunately, these drivers are quite large overall which makes them not quite ideal for many car audio installs.

But for home audio and studio monitors they will no doubt be extremely good.

Check the pricing and measurements at the link...






Transducers Archives - PURIFI







purifi-audio.com


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## Niebur3 (Jul 11, 2008)

Definitely interesting drivers. Any idea of the pricing on the 4"?


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## bbfoto (Aug 28, 2005)

Niebur3 said:


> Definitely interesting drivers. Any idea of the pricing on the 4"?


Current normal single-unit pricing is about $280 USD at the current exchange rate. I haven't asked about quantity pricing yet, however Claus Neesgaard's email suggested a very similar and advantageous quantity discount on par with the 6.5" iteration (see previous posts & links).

While they are completely different drivers in terms of form factor, even the normal, single-unit price is reasonable when compared to the Dynaudio E2 430, Scanspeak 12M/12MU, or Focal Utopia Elite 3.5WM, etc. And I'm fairly certain that performance would be at least on-par, with obviously more linear excursion capability. 

I also need to check on the development progress of their 8" driver. However, I fear that it will also be a somewhat large form-factor driver.

This is just one reason that I love the shallow-mount Focal Utopia Elite 8WM, though it is stupid expensive and does not have anywhere near the linear excursion capability that the 8" Purifi driver will offer.


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## SloVic (Oct 1, 2016)

bbfoto said:


> I also need to check on the development progress of their 8" driver. However, I fear that it will also be a somewhat large form-factor driver.


Any word on those?


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## bbfoto (Aug 28, 2005)

SloVic said:


> Any word on those?


Sorry. No. I've been slacking. Go to the website and contact them. They are usually very responsive, but give them a few days as they are in Denmark.






About - PURIFI







purifi-audio.com





[email protected]


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## SloVic (Oct 1, 2016)

Said they hope to have a preview of the 8" in "1H21". Guessing that means 1st half of 2021.


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## bbfoto (Aug 28, 2005)

Hello gents. I'm reviving this thread as I have another project that I think these Purifi 6.5" midwoofers would be suitable for.

If anyone has a pair in excellent condition they want to sell, please contact me here via PM, or Email me at bbfoto AT hotmail DOT com

Please include "Purifi 6.5", "DIYMA" and your Screen Name in the email Subject.

If no one has a pair for sale, let me know if any of you are still interested in acquiring these as well???

We could potentially do a "group buy" order to receive a substantial discount via multiple pair pricing.

Cheers!

EDIT: I've already acquired another pair for my project so am no longer considering a Group Buy. Thanks


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## SloVic (Oct 1, 2016)

bbfoto said:


> Sorry. No. I've been slacking. Go to the website and contact them. They are usually very responsive, but give them a few days as they are in Denmark.
> 
> 
> 
> ...


The specs for the 8" are now posted on their site so they should be available fairly soon. They also have 5" and some different membrane options.


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## bbfoto (Aug 28, 2005)

SloVic said:


> The specs for the 8" are now posted on their site so they should be available fairly soon. They also have 5" and some different membrane options.


Thanks! Yeah, someone on the recent @ErinH livestream chat brought them up and Erin is working on acquiring them to test on the Klippel along with several of the other Purifi drivers that he already has in-hand. Subscribe to the *Erin's Audio Corner* YouTube channel and enable All Notifications to keep updated.


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