Purifi PTT6.5W04-01A 6.5" midwoofer

[Audiocrusader]

Let's put this into perspective. It's just a woofer. One of many thousands of 6.5" woofers that have graced the earth. Plenty of good ones before and there will be plenty of good ones after these have come and gone.

It's not a cure for cancer, a faster than light propulsion unit, a teleportation device, or a time machine is it? Jeez.

I suppose that same argument could be used for every thread on this forum. Does that mean nothing should be discussed at all unless it cures cancer, is faster than light propulsion unit, a teleportation device, or a time machine? No I think that would be asking a bit much for an audio forum. However the fact remains that any "opinions" about anything that aren't backed up by hard data is useless information.

 

[Audiocrusader]

But you could have this graphene-coated uber midwoofer instead....

https://www.madisoundspeakerstore.c...w18ex-003-e0074-7-graphene-cone-woofer-8-ohm/

Only $500 each.

But it's from a legit driver maker with a proven history decades long.

Bruno used the same drivers without the graphene coating in the Grimm speakers. And he also uses SEAS mids and tweeters in the KII speakers. So I can assure you these were used as a reference in the testing. The folks who run the Purifi transducer division are among the most experienced in the driver industry. They're not just electronics manufacturers:

• Carsten Tinggaard, Co-Owner (PURIFI Transducer Technology)
  Founder and owner of PointSource Acoustics (2009). Previously Product Manager for Danish Sound Technology (2003) and CTO of Tymphany Denmark (2005) responsible for establishing R&D Denmark facility covering Peerless, Vifa and Scan-Speak brands. Spearheaded Peerless tech. transfer to China manufacturing facilities. Co-owner of PURIFI Transducer Technology (2017), a subsidiary of PURIFI.

• Morten Halvorsen, R&D Acoustics (PURIFI Transducer Tech.)
  Worked as Senior Acoustic Engineer at PointSource Acoustics. Co-developed both the loudspeakers and sound unit of the Montana Sound and SoundBy PointSource products. Specialized in electromagnetic simulations, measurements and procedure optimization. Researched force factor modulation, developing measurement equipment and simulation models. Results presented at AES 138. M.Sc.E.E. with specialization in acoustics from DTU (2014).

 

[Audiocrusader]

Some pictures:

 

[RayDunzl]

That surround just looks wrong...

 

[Biblob]

That surround just looks wrong...

Ain't that awesome?

 

[boXem]

I find quite interesting that on a "science" forum the only reactions to a surround shape which is obviously the result of computer assisted design are:

It's a fuggin ugly driver alright. Looks like some clown with a heat gun has attacked the surround.

That surround just looks wrong...

Measurements are also provided, on which nobody gives a f..., for the good or for the bad.

You guys are funny sometimes

 

[Killingbeans]

And at the end of the day, only folks with direct experience with them have any valid input to add to the thread whatsoever. And this is regardless of how self important these folks feel about themselves.

I see no harm in interpreting the data and measurements that is already made public.

I suppose that same argument could be used for every thread on this forum. Does that mean nothing should be discussed at all unless it cures cancer, is faster than light propulsion unit, a teleportation device, or a time machine? No I think that would be asking a bit much for an audio forum. However the fact remains that any "opinions" about anything that aren't backed up by hard data is useless information.

You are absolutely right. But restorer-john was probably mostly just responding to your hostility.

Keep calm and supply the data. No need to throw diplomacy out the window.

 

[Killingbeans]

@boXem

Exactly! In this case form follows function. I guess it's easier to swallow that pill when the form is hidden away inside a pretty enclosure

 

[Audiocrusader]

I see no harm in interpreting the data and measurements that is already made public.



You are absolutely right. But restorer-john was probably mostly just responding to your hostility.

Keep calm and supply the data. No need to throw diplomacy out the window.

My initial post in this thread was in response to the fact that 70-80% of the posts in this forum are nothing but hot air. Restorer-John thinks any gear that wasn't made in his glory days of the 70's-80's is junk. When in reality, inflation adjusted, the best gear from that era can't even hold a candle to gear costing a fraction of the price today. Watchnerd is suggesting an 18 yr old SEAS driver with a graphene powder coating must be superior, without an ounce of data to back it up. And the reasoning is because the Purifi team are only electronic's manufacturers. Which is also false information.

The Purifi amp thread (outside of the couple posts made by Bruno) is an absolute disaster riddled with copious amounts of misinformation and hot air. So when I seen this thread off to the same start I decided to respond. The problem is likely around 70-80% of the folks who read these threads don't have the technical knowledge to decipher the facts from the BS. So what happens much of the time is they think the BS is indeed factual. Then they start spreading it themselves across other forums. And then after a while total BS becomes the truth in the minds of the masses.

 

[Killingbeans]

My initial post in this thread was in response to the fact that 70-80% of the posts in this forum are nothing but hot air.

I understand your frustration. Believe me, I do. I started this thread with the hopes of getting a usefull technical discussion going.

But any thead will inevitably mostly have reaction based comments in the first stage of its lifespan. It's not necessarily malicious.

There's no need to jump directly from "I understand your scepticism, but here's why it deserves your attention" to "Pull your head out off your ass!!!".

That way we'll end up with "my dad can beat up your dad" kind of talk in no time, and that's definitely not something I want to see

 

[617]

My initial post in this thread was in response to the fact that 70-80% of the posts in this forum are nothing but hot air. Restorer-John thinks any gear that wasn't made in his glory days of the 70's-80's is junk. When in reality, inflation adjusted, the best gear from that era can't even hold a candle to gear costing a fraction of the price today. Watchnerd is suggesting an 18 yr old SEAS driver with a graphene powder coating must be superior, without an ounce of data to back it up. And the reasoning is because the Purifi team are only electronic's manufacturers. Which is also false information.

The Purifi amp thread (outside of the couple posts made by Bruno) is an absolute disaster riddled with copious amounts of misinformation and hot air. So when I seen this thread off to the same start I decided to respond. The problem is likely around 70-80% of the folks who read these threads don't have the technical knowledge to decipher the facts from the BS. So what happens much of the time is they think the BS is indeed factual. Then they start spreading it themselves across other forums. And then after a while total BS becomes the truth in the minds of the masses.

Yeah I agree with you. This won't be a cheap driver and it's not going to be better than everything else, but it looks like an interesting and viable driver with a very good panel of measurements. The surround looks odd but it's an obvious place to introduce asymmetry, similar to the surround extensions in the Peerless NE series woofers.

This driver looks like a joy to work with, with no breakup louder than the pass band, low distortion, extended treble, no cone edge resonance.

I also find it comical that people balk at $500 dollar woofer when it's by far the most important part of your audio system. Not to say I was impressed by the Seas graphene range but I would buy an Ellipticor in a heartbeat.

If anyone was wondering, the copper plug on the Seas magnesium drivers is both a phase plug and to provide cooling.

 

[Audiocrusader]

The end result of the surround design is extremely low IM distortion in the midrange, while producing extremely high SPL's down to 35hz. So you have the volume displacement of a typical 10" woofer, and the midrange quality of a dedicated midrange, even when the cone is violently flapping back and forth outputting 110dB SPL. There's no other driver available to my knowledge that can produce IM distortion this low in the midband, while at the same time moving copious amounts of air down to 35hz. It pretty much makes 3 way speakers obsolete. So due to these facts this driver truly is a game changer.

I suppose the surround isn't the only innovation. You can see there's another cone attached to the back of the cone to add rigidity. The voice coil is also massive. The spider is also designed to store very little energy.

 

[Killingbeans]

The Purifi amp thread (outside of the couple posts made by Bruno) is an absolute disaster riddled with copious amounts of misinformation and hot air.

Are you talking about maty? Yeah... that guy is nuts. But seems mostly harmless. I have nothing against him personally, but I can't really get a grip on him. Sometimes I think he's some sort of a failed attempt at programming an AI.

As long as he doesn't come in here and start screaming about phase shift, we should be fine

 

[617]

Plugging the numbers into WinISD, this is a very usable driver.

Happy in a .4 cu ft. box, where it has an f3 of 38hz, excursion limited at around 100W, where it is producing 108db at 1m. Probably not capable of 100W continuous but this is quite a beast, especially considering the lack of treble resonances. Seems easily competitive with Illuminators.

The Anarchy woofers were the first which sort of showed a 7" could be better than many good 8" drivers, and these seem to have similar performance in the bass with superior treble extension.

 

[Audiocrusader]

Are you talking about maty? Yeah... that guy is nuts. But seems mostly harmless. I have nothing against him personally, but I can't really get a grip on him. Sometimes I think he's some sort of a failed attempt at programming an AI.

As long as he doesn't come in here and start screaming about phase shift, we should be fine

Don't say his name he can hear for 20000 miles.

 

[Audiocrusader]

Distortion up to 108-109db:

 

[briskly]

Regarding the Seas cones, the graphene coating is there as a protective paint. Seas' magnesium cones have been known to oxidize. The motor appears fairly well made, but the price is no doubt difficult to swallow. I'm not sure about it being a phase plug in the usual sense of aligning path lengths in a compression driver, but punching out the dust cap would change the off-axis somehow.

I don't see the Purifi as a match for a 10" woofer with only 10mm linear stroke, but you get the smaller cabinet and CTC. Tweeter waveguides built to match can be made smaller as well.

 

[Audiocrusader]

$700 7" Scan Speak Ellipticor woofer distortion. No SPL provided. So at 1khz it has higher distortion than the Purifi when playing flat out at 108-109db!

 

[Audiocrusader]

I don't see the Purifi as a match for a 10" woofer with only 10mm linear stroke, but you get the smaller cabinet and CTC. Tweeter waveguides built to match can be made smaller as well.

Use 2 of them and it will be more than a match. Ideal driver for a 2.5 way tower.

 

[617]

$700 7" Scan Speak Ellipticor woofer distortion. No SPL provided. So at 1khz it has higher distortion than the Purifi when playing flat out at 108-109db!

View attachment 37864

There's no standard for woofer distortion measurements as far as I know, so I wouldn't make this comparison. Suffice to say they're both good.