Thanks for the excellent review. One comment regarding the surround: From my understanding the unusual shape was developed to keep the piston area (Sd) "constant" at high excursions. The area of the surround is not negligible for drivers of this size, so keeping the Sd constant actually reduces third order distortion.
Good gracious! Been designing and building speakers for decades, didn't realize there were no-nonsense people like you doing measurements and discussing them on YT! Keep up the great work! Subcribed! By the way, one aspect you're not explicitly mentioning that should have quite a positive impact on how a speaker using this driver will sound is the mechanical Q-factor: that's impressive as well!
Hi Erin, First up I love these things the more that I listen to them, levels of clarity better than anything I have heard to date. I noticed that in the two reviews of these Purify 6.5 inch drivers you keep mentioning offhand that the drivers should be high-passed. But you never articulated why? Here are my thoughts about the drivers. I purchased two of the 8 ohm versions and placed them directly in my HEDD V1 type 20s (no internal dsp), swapping out the original 6.5 inch drivers. I have a highly resolving system and highly treated nearfield studio. What I do agree with is in the midrange, dam these things are wickedly accurate. A whole other level to any driver I have heard before. But a couple of things. 1) The curve of course shows not much bass at all. Yet the prob is the bass down there is really one-note. Even mid-bass is pretty sketchy. Midrange awesome, go lower and.... 2) So the drivers are pitched as a high excursion driver. OK, but high excursion is mostly useful with bass. So here is the thing that I cringe to say because this is a jewel of a driver. Ready for it? At high excursion, meaning loud playing mid-bass & bass, Those surrounds stop doing their delicate low distortion from the sound thing. And .....they literally flop back and forth. Not so much in and out, but a distinct back and forth. When you move the driver by hand at high excursions you can see it. And that flopping back and forth of the surround. Makes a distinct very audible sound. It sounds like rubber flopping back and forth at high speed. Moving your ear around close to the driver, it is the surrounds. So this is really easy to control by either backing off on volume, thus less excursion. Or alternatively by high passing so that long excursion frequencies cannot find their way to the driver. I think that this did not show up in your tests, because the volume and duration of your test tone sweep would not show it. If you placed the driver in a real box and played music through it loud you definitely will hear it. My pass is incredible drivers, for midrange, incredible, and the surrounds work perfect in that range. But don't get sold on the long excursion part of the pitch. I do plan to get a pair of the Purify 8 inch aluminum coned drivers when they are available in December. Looking forward to them for all they look like they can do. Just hoping I don't get bit by the long throw causing the surrounds to flop back and forth thing. Because I do want them to perform and hit with low-distortion as a woofer.
This driver is masterpiece! Bought it because your review and oh my god it beats audio frog gb60 in ib install hands down! Even tho gb60 is pretty good purifi is whole another level.. only can imagine what it would be like as studio monitor in proper enclosure! Maybe will buy 8inch alu version for home😱 purifi is like 6db louder in my car than audiofrog and lower the frequency, bigger the cap against gb60. Crossover point is 35hz 24db and I have hard time to get these to go over mech excursion with 85watts...
That surround looks like it got to close to the sun. Still if it works it works. I only knew purifi for their class D modules. Now I want their speakers too.
This one with long coil, short gap or the underhanged Scan. This 'could' be easier to apply with in passive x-o. But, Scan has a little better efficiency, and I like their design choice more. Tough choice ... Now we need tweeter to go down to 1.5kHz to match the performance. But there are also other 'Purifiers' with shorter coil and slightly higher efficient due to shorter coils, and they're less $$$. So maybe two of these + tweeter, is a better idea.
Compare apples to apples. There is absolutely no way that Seas driver has 22mm linear excursion one-way. I’d wager it can’t even move 22mm one-way mechanically. Make sure you are comparing apples to apples. Not all Xmax specs are created equal.
Hey Erin, I was planning on building an open baffle Linkwitz Lx521.4 pair of speakers and these drivers sound like they would be a great fit for the mid range. the Lx521.4 heavy uses DSP with active crossovers but I am concerned about the low QTS ~0.4. Do you believe this should be a concern with the Lx521.4 design being open baffle? Thanks.
I was wondering if the surround is designed to deal with the air pressure in an enclosure with a high excursion driver, like this? The KEF KC62 subwoofer driver has a "folded" sort of surround for this reason. So, it resists buckling under negative pressure, *without* being really stiff and thick - which obviously has a big effect on distortion and response.
I'm not sure if you saw the interview I did with Lars Risbo of PURIFI. If you have not, you might want to check it out. I have provided a link below to the particular portion of the discussion where Lars talks about the surround design. th-cam.com/video/o90AYyceaMI/w-d-xo.html
These purify drivers look amazing! Would you know any all in one 4 way plate amps with DSP? Similar to the hypex ncore stuff. But I would really love to find one that allows for a 4 way design
Interesting that we now know that those 'holes' behind the dustcap is not for cooling, they are there to stop pressure building up in front of the pole piece - I think a lot of us got that wrong.
I couldn’t understand the name and company of the build Please can u let me know don’t get to see people talk of Purifi woofer thank you Also very eager to know your opinion and review on the 4” purifi
This reminds me of a question I asked Paul at P.S.Audio (but never got an answer,) all dynamic drivers are comprised of basically the same elements, frame, cone, voice coil, surround, spider. So what makes one driver $12 and another $400?
What about the 4.5" model? Would the higher extension have less distortion than the 6.5" and would the midrange frequencies for vocals be even better, wifh a crossover point of, say, 2.5 Hz?
A ~.5cu.ft ported box turned so low around 22hz would pretty much be impossible to fit a port of reasonable size. Plus why not maximize efficiency in the useful range? Not a lot of music has content so low in frequency!
Like I said in the video, the models were quick and just to give you an idea. You’d need to model them yourself to see what you need. I said that twice, actually. ;)
Hi, Thanks for the data, measurement and everything you do, really helpfull and usefull. I got Arendal 1723 bookshelf s, They have 6,5 inch woofer, what do you think if i upgrade them to purifi woofer? Is it any good idea? The Arendal has 1500hz crossover. And i have subwoofer which i can crossover 100hz. Thanks
Hi friend, excellent review with a lot info How’s this woofer compare with Audifrog GB60 and if they compare. Looking fire a good or better Midbass than the GB60 with 200 watts rms power. And with dsp set up
I have a pair 6.5" Purifi woofers what would be the box size sealed where I can get max bass in sesled. Also was thinking of a dome tweeter to make a 2 way bookshelf
I saw madisound they say 20 -.30 cf sealed for an F3 of 87Hz That not what I want how to go lower in sesled no one says on internet And I don't wish to buy Purifi passive radiator as much as possible. I am new in diy so learning
Check out winisd. It is free software that will allow you to model different size enclosures to determine what works best for your needs. As a DIY'r this will be an invaluable tool for you not just now but in the future as well. :)
Would be really interesting if could check out and perhaps review a speaker from the live sound company , KV2 Audio. Uncle George Krampera is really into audio quality.
@@Iconroller Yeah the reference design uses the AMT tweeters. The reference design however measures pretty bad. The tweeter is quite overpriced for it's performance.
I am no expert but gonna try the GRS planar tweeters in the car Also got the 4” and 6.5” Purifi will see how best it goes in a MUV and 1 sealed box also have AutoTuba based on tang band 8” let’s see how it works
It's odd that Purifi doesn't sell speakers, they only sell drivers for DIY folks who make their own. It seems like they're giving up a good market opportunity.
I have a friend using them in his car doors right now. He loves them. They are IB. Not sure where his crossover is. I would imagine >60Hz. If I were to use them I would consider trying to put them in an enclosure if I had the space in the car.
Dude you have a very similar presentation to AdamKoraik - not sure if you’re into gaming at all, but check out his channel for just one example of your TH-cam doppelgänger, lol.
Thanks for the excellent review. One comment regarding the surround: From my understanding the unusual shape was developed to keep the piston area (Sd) "constant" at high excursions. The area of the surround is not negligible for drivers of this size, so keeping the Sd constant actually reduces third order distortion.
Dude your down to Earth presentation is fantastic - well done dude
Thanks!
This is incredibly amazing. Not just the video, but what you do here too. Subscribed; huge respect to people who are into audio science.
Good gracious! Been designing and building speakers for decades, didn't realize there were no-nonsense people like you doing measurements and discussing them on YT! Keep up the great work! Subcribed!
By the way, one aspect you're not explicitly mentioning that should have quite a positive impact on how a speaker using this driver will sound is the mechanical Q-factor: that's impressive as well!
I appreciate that!
The brain-trust @ Purifi = their Kung Fu is good
Seriously, they're doing exciting things, moving the state of the art forward in meaningful ways.
What an amazing woofer. And what a great review. Just shared with 2 of my audio friends.
Awesome, thank you!
Hi Erin, First up I love these things the more that I listen to them, levels of clarity better than anything I have heard to date.
I noticed that in the two reviews of these Purify 6.5 inch drivers you keep mentioning offhand that the drivers should be high-passed. But you never articulated why? Here are my thoughts about the drivers. I purchased two of the 8 ohm versions and placed them directly in my HEDD V1 type 20s (no internal dsp), swapping out the original 6.5 inch drivers. I have a highly resolving system and highly treated nearfield studio. What I do agree with is in the midrange, dam these things are wickedly accurate. A whole other level to any driver I have heard before. But a couple of things. 1) The curve of course shows not much bass at all. Yet the prob is the bass down there is really one-note. Even mid-bass is pretty sketchy. Midrange awesome, go lower and.... 2) So the drivers are pitched as a high excursion driver. OK, but high excursion is mostly useful with bass.
So here is the thing that I cringe to say because this is a jewel of a driver. Ready for it? At high excursion, meaning loud playing mid-bass & bass, Those surrounds stop doing their delicate low distortion from the sound thing. And .....they literally flop back and forth. Not so much in and out, but a distinct back and forth. When you move the driver by hand at high excursions you can see it. And that flopping back and forth of the surround. Makes a distinct very audible sound. It sounds like rubber flopping back and forth at high speed. Moving your ear around close to the driver, it is the surrounds. So this is really easy to control by either backing off on volume, thus less excursion. Or alternatively by high passing so that long excursion frequencies cannot find their way to the driver.
I think that this did not show up in your tests, because the volume and duration of your test tone sweep would not show it. If you placed the driver in a real box and played music through it loud you definitely will hear it.
My pass is incredible drivers, for midrange, incredible, and the surrounds work perfect in that range. But don't get sold on the long excursion part of the pitch.
I do plan to get a pair of the Purify 8 inch aluminum coned drivers when they are available in December. Looking forward to them for all they look like they can do. Just hoping I don't get bit by the long throw causing the surrounds to flop back and forth thing. Because I do want them to perform and hit with low-distortion as a woofer.
This driver is masterpiece! Bought it because your review and oh my god it beats audio frog gb60 in ib install hands down! Even tho gb60 is pretty good purifi is whole another level.. only can imagine what it would be like as studio monitor in proper enclosure! Maybe will buy 8inch alu version for home😱 purifi is like 6db louder in my car than audiofrog and lower the frequency, bigger the cap against gb60. Crossover point is 35hz 24db and I have hard time to get these to go over mech excursion with 85watts...
That surround looks like it got to close to the sun. Still if it works it works. I only knew purifi for their class D modules. Now I want their speakers too.
This one with long coil, short gap or the underhanged Scan. This 'could' be easier to apply with in passive x-o. But, Scan has a little better efficiency, and I like their design choice more. Tough choice ...
Now we need tweeter to go down to 1.5kHz to match the performance.
But there are also other 'Purifiers' with shorter coil and slightly higher efficient due to shorter coils, and they're less $$$. So maybe two of these + tweeter, is a better idea.
New sub here, I'm digging this, very much appreciate the content. I fully understand how much is involved, so good lookin' out.
Thanks and welcome!
seas titan 6" woofer has 22mm excursion, thats was is used in ascend acoustics sierra lx
Compare apples to apples. There is absolutely no way that Seas driver has 22mm linear excursion one-way. I’d wager it can’t even move 22mm one-way mechanically. Make sure you are comparing apples to apples. Not all Xmax specs are created equal.
Hi. Do you have any suggestions on how many watt tweeters I should use with this 3-way speaker? With purifi ptt6.5x04-nfa-01
Hey Erin, I was planning on building an open baffle Linkwitz Lx521.4 pair of speakers and these drivers sound like they would be a great fit for the mid range. the Lx521.4 heavy uses DSP with active crossovers but I am concerned about the low QTS ~0.4. Do you believe this should be a concern with the Lx521.4 design being open baffle? Thanks.
Thank you for your reviews. Using this driver in a sealed enclosure for car audio, what would you recommend for RMS amp power?
Been looking into Purifi could you review the
PTT8.0X08NAB01
I was wondering if the surround is designed to deal with the air pressure in an enclosure with a high excursion driver, like this? The KEF KC62 subwoofer driver has a "folded" sort of surround for this reason. So, it resists buckling under negative pressure, *without* being really stiff and thick - which obviously has a big effect on distortion and response.
I'm not sure if you saw the interview I did with Lars Risbo of PURIFI. If you have not, you might want to check it out. I have provided a link below to the particular portion of the discussion where Lars talks about the surround design.
th-cam.com/video/o90AYyceaMI/w-d-xo.html
These purify drivers look amazing!
Would you know any all in one 4 way plate amps with DSP? Similar to the hypex ncore stuff. But I would really love to find one that allows for a 4 way design
Not off the top of my head.
Interesting that we now know that those 'holes' behind the dustcap is not for cooling, they are there to stop pressure building up in front of the pole piece - I think a lot of us got that wrong.
I couldn’t understand the name and company of the build
Please can u let me know don’t get to see people talk of Purifi woofer thank you
Also very eager to know your opinion and review on the 4” purifi
Selah Purezza.
Here's the link to my review:
www.erinsaudiocorner.com/loudspeakers/selah_audio_purezza/
This reminds me of a question I asked Paul at P.S.Audio (but never got an answer,) all dynamic drivers are comprised of basically the same elements, frame, cone, voice coil, surround, spider.
So what makes one driver $12 and another $400?
Here is why, from one of the engineers himself:
th-cam.com/video/o90AYyceaMI/w-d-xo.html
What about the 4.5" model? Would the higher extension have less distortion than the 6.5" and would the midrange frequencies for vocals be even better, wifh a crossover point of, say, 2.5 Hz?
I've got a pair on hand to review. Not sure when the review will be completed and posted, but it's coming.
A ~.5cu.ft ported box turned so low around 22hz would pretty much be impossible to fit a port of reasonable size. Plus why not maximize efficiency in the useful range? Not a lot of music has content so low in frequency!
Like I said in the video, the models were quick and just to give you an idea. You’d need to model them yourself to see what you need. I said that twice, actually. ;)
@@ErinsAudioCorner I really appreciate all the work you do testing all these drivers for us, thank you!
@@CorradoVR6z thank you for tuning in. :)
Hi,
Thanks for the data, measurement and everything you do, really helpfull and usefull.
I got Arendal 1723 bookshelf s,
They have 6,5 inch woofer, what do you think if i upgrade them to purifi woofer?
Is it any good idea? The Arendal has 1500hz crossover. And i have subwoofer which i can crossover 100hz.
Thanks
Hi friend, excellent review with a lot info
How’s this woofer compare with Audifrog GB60 and if they compare. Looking fire a good or better Midbass than the GB60 with 200 watts rms power.
And with dsp set up
I have a pair 6.5" Purifi woofers what would be the box size sealed where I can get max bass in sesled. Also was thinking of a dome tweeter to make a 2 way bookshelf
I'm not sure off the top. You could see if Madisound has recommendations on enclosure size. Normally they do.
I saw madisound they say 20 -.30 cf sealed for an F3 of 87Hz
That not what I want how to go lower in sesled no one says on internet
And I don't wish to buy Purifi passive radiator as much as possible.
I am new in diy so learning
Check out winisd. It is free software that will allow you to model different size enclosures to determine what works best for your needs. As a DIY'r this will be an invaluable tool for you not just now but in the future as well. :)
The ellipticor doesn't have the surround issue I believe. And overall distortion levels just as good. Twice the price of course 😂
Would be really interesting if could check out and perhaps review a speaker from the live sound company , KV2 Audio. Uncle George Krampera is really into audio quality.
what tweeter would u recommend with this 6.5 for car use? Great Review
The bliesma beryllium are great with them!
I’ve seen this driver used with the new mundorf amt tweeters
@@Iconroller Yeah the reference design uses the AMT tweeters. The reference design however measures pretty bad.
The tweeter is quite overpriced for it's performance.
I am no expert but gonna try the GRS planar tweeters in the car
Also got the 4” and 6.5” Purifi will see how best it goes in a MUV and 1 sealed box also have AutoTuba based on tang band 8” let’s see how it works
ScanSpeak D2608/913000 26mm dome tweeter 8ohm.
Could you tell me the difference between 6.5 inch scanspeak, satori, AudioTechnology and this? Are these all on the same level or does one standout?
They're all high quality speakers. It really comes down to needs (enclosure, desired crossover, speaker type, output levels).
this is a breakout product, advanced tech yielding audible improvements the same way the purifi amp modules left ICE and Hypex modules in the dust
It's odd that Purifi doesn't sell speakers, they only sell drivers for DIY folks who make their own. It seems like they're giving up a good market opportunity.
Love the goonies shirt 👍
I have a dirt bike kid movie shirt also have a RAD shirt. Crew joans is the man.
I've got a RAD shirt in the closet that no longer fits me. I also still have a bootlegged DVD I ordered off eBay back around 2005. Good times. :D
@@ErinsAudioCorner I also have the same DVD 👍
Anyone can suggest what would be a good Purifi based good OB config for a medium sized room
OBs normally uses large diaphragms and have a high Qts, so I suppose these are not that good for this application.
Erin will u recommend in car the Purifi 6-4” in car
How would u use it
I have a friend using them in his car doors right now. He loves them. They are IB. Not sure where his crossover is. I would imagine >60Hz. If I were to use them I would consider trying to put them in an enclosure if I had the space in the car.
Dude you have a very similar presentation to AdamKoraik - not sure if you’re into gaming at all, but check out his channel for just one example of your TH-cam doppelgänger, lol.
Not familiar with him. Pulled up his page. First video is a Back to the Future video. I like this guy already!
Seas are just as good for half the money ...
Purezza, not Impreza
Details. 🤪
I got it right when I reviewed the Purezza. 👍😁
Did you just say "Jiff"?
I still have no idea what the correct pronunciation is. And that stupid peanut butter commercial doesn’t help.
Yep, GIF's daddy pronounces it "jiff."
www.cnn.com/2015/03/01/tech/web/how-to-pronounce-gif/index.html
Really! used in a car, what a waste...Design a high end loudspeaker and incorperate this unit.