Purifi PTT6.5W04-01A 6.5" midwoofer

[Killingbeans]

First off I'd like to make it clear that transducers/drivers is a subject that my expertise doesn't cover very well. In other words, if I happen to ask some hopelessly trivial questions or get giddy about next to nothing, feel free to answer with something in the line of: "Read this book/article first, and then we can talk"

Anywho, with all the raving about the Purifi 1ET400A Class D amp, I couldn't help but notice their other product about to get launched, the PTT6.5W04-01A speaker driver.

More info here. (Purifi's web page)

EDIT: Extensive measurements and additional information here on HiFiCompass.com

I've been meaning to build myself some new DIY speakers for ages, but never really get around to much more than dreaming and doing superficial research. I'd like some small bookshelf speakers with high WAF without sacrificing too much fidelity, and these drivers seem to be designed to address some of the problems pestering small long-stroke drivers. I must admit that I am ill equipped with the knowledge required to determine whether it's just hot air, or something worth extraordinary praise... or something in between. I trust the scrutiny of you guys to set me straight?

Purifi seem to be demoing it in a small (sealed?) encosure paired with a Mundorf AMT (as seen in this article):

EDIT: The box is ported, and there's a description of it here: SPK4 (simpel demo enclosure)

EDIT2: And here's a review of the SPK4.

It also seems that March Audio is going to use this driver in an upcoming active speaker? Maybe he would like to chime in?

BTW, feel free to use this thread for general talk about this driver.

 

[kaka89]

I would like to know how much a driver have to do to distortion, comparing to other factors like cabinet, horn, crossover etc. I remember Dutch & Dutch people claim that material has very little to do on how a driver performs. (I know didn't mean driver design does not matter)

What is the problem of other drivers on the market? aren't they flat.

 

[maxxevv]

While you're at it, why not build it as powered speakers with the Purifi amp modules build in ??

 

[restorer-john]

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

Looks like they are re-resurrecting the wierd roll surrounds everyone was doing in the 80s for more "linear" excursions. (they all fell to pieces eventually)

I see there is an Aldi doorstopper on the floor- must've borrowed it from that Darko guy...

https://darko.audio/2018/12/doorstop-me-if-you-think-youve-heard-this-one-before/

 

[briskly]

Product brief doesn't list power rating. Harmonic testing goes to 28.3 Vrms input, which is a lot for a small 4-ohm nominal driver, but that can be tested in a very short time. No price given either. Volume displacement is in the range of 8-inch midwoofers.
It seems better behaved above 1kHz than some other small long-stroke drivers, such as the Scan-Speak 18WU(paper and metal versions) and the Anarchy 7. Lumped parameters don't suggest that it is friendly to a port if you expect to use it at higher SPL. Consider a closed box with target Q around 0.5-0.6 plus EQ to lift the low end or use passive radiators.

 

[watchnerd]

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.

 

[restorer-john]

But you could have this graphene-coated uber midwoofer instead

That wooger looks like it has a copper bullet too- must be good eh? $500 for that. The world has gone mad.

 

[watchnerd]

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

Looks like they are re-resurrecting the wierd roll surrounds everyone was doing in the 80s for more "linear" excursions. (they all fell to pieces eventually)

I see there is an Aldi doorstopper on the floor- must've borrowed it from that Darko guy...

View attachment 37827

https://darko.audio/2018/12/doorstop-me-if-you-think-youve-heard-this-one-before/

I thought you were taking a piss about the Aldi door stop...

 

[watchnerd]

That wooger looks like it has a copper bullet too- must be good eh? $500 for that. The world has gone mad.

At least it's made by people who make drivers for a living, as opposed to electronics....

And if you're going to to pony up for the graphene bragging rights, you need something eye catching like a copper plug to start the bragging conversation.

 

[restorer-john]

you need something eye catching like a copper plug

More like eye-watering...

 

[March Audio]

First off I'd like to make it clear that transducers/drivers is a subject that my expertise doesn't cover very well. In other words, if I happen to ask some hopelessly trivial questions or get giddy about next to nothing, feel free to answer with something in the line of: "Read this book/article first, and then we can talk"

Anywho, with all the raving about the Purifi 1ET400A Class D amp, I couldn't help but notice their other product about to get launched, the PTT6.5W04-01A speaker driver.

More info here.

I've been meaning to build myself some new DIY speakers for ages, but never really get around to much more than dreaming and doing superficial research. I'd like some small bookshelf speakers with high WAF without sacrificing too much fidelity, and these drivers seem to be designed to address some of the problems pestering small long-stroke drivers. I must admit that I am ill equipped with the knowledge required to determine whether it's just hot air, or something worth extraordinary praise... or something in between. I trust the scrutiny of you guys to set me straight?

Purifi seem to be demoing it in a small (sealed?) encosure paired with a Mundorf AMT (as seen in this article):

It also seems that March Audio is going to use this driver in an upcoming active speaker? Maybe he would like to chime in?

BTW, feel free to use this thread for general talk about this driver.

There will be an active and passive version. The passive market is too big to ignore. I was trying to get a prototype ready for the Melbourne show but Purifi didnt have the drivers available in time.

I use the Mudorf AMT in my main speakers, active 3 way and its excellent there, but for a 2 way you have got to start making compromises on the crossover point (how low you can go.)

Probably not going to say too much else at this moment.

 

[Audiocrusader]

Although what’s missing from this conversation is facts. Misinformation seems to be what’s preferred among audio forum crusaders. However for anyone who’s more interested in facts than what the self proclaimed professionals with no experience that extends beyond their heads buried in their asses, these drivers were designed by folks who are among the finest driver designers in the world. 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.

 

[watchnerd]

More like eye-watering...

View attachment 37833

Damn Google image search for informing me what that is.

I thought it was one of those mystical audio tuning products.

 

[Thomas savage]

Damn Google image search for informing me what that is.

I thought it was one of those mystical audio tuning products.

Turns out those ' spare door handles ' your dad kept in the garage where not ' spare door handles ' after all...

 

[Thomas savage]

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.

Similar to the bass/mid on my old proac d15's.. minus the grapheme.

 

[watchnerd]

Similar to the bass/mid on my old proac d15's.. minus the grapheme.

Why'd you ever get rid of any speaker with a fancy copper plug?

 

[restorer-john]

Although what’s missing from this conversation is facts. Misinformation seems to be what’s preferred among audio forum crusaders. However for anyone who’s more interested in facts than what the self proclaimed professionals with no experience that extends beyond their heads buried in their asses, these drivers were designed by folks who are among the finest driver designers in the world. 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.

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.

 

[Thomas savage]

Why'd you ever get rid of any speaker with a fancy copper plug?

They triggered some suppressed memories from my childhood..

 

[mk1classic]

Will the PTT6.5W04-01A driver be available for the DIY market?
It would be fun to try it out with a Bliesma T34B-4 34mm Beryllium Dome Tweeter

 

[Killingbeans]

While you're at it, why not build it as powered speakers with the Purifi amp modules build in ??

I've thought about it. I'd probably go with NC400 for the power. But in the end, if someone makes a nice passive design public and backs it with measurements, I'll most likely just use that.

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

It's not pretty, that's for sure. But it still lowers the WAF substantially less than 'there's no replacement for displacement' -speakers

Looks like they are re-resurrecting the wierd roll surrounds everyone was doing in the 80s for more "linear" excursions. (they all fell to pieces eventually)

That is a point of concern, yes. I'm keeping my fingers crossed for material science having found something less prone to crumbling since then.

I see there is an Aldi doorstopper on the floor- must've borrowed it from that Darko guy...

At least they are using it for its original purpose

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

At least it's made by people who make drivers for a living, as opposed to electronics....

If you look at the about page on their website, you can see that the transducer branch is run by legitimate transducer guys