Email him. Last time I asked (several weeks ago) they had stock available in the US, paid for with normal US payment methods.
Any progress on this? Very excited for a woofer with these specs....thank you for your participation on this forum.
It seems some problems had been occurred with March audio Sointuva WG's build.
Check the link below.
https://www.audiosciencereview.com/...and-reinforcements-with-klippel-device.35255/
Check the link below.
https://www.audiosciencereview.com/...and-reinforcements-with-klippel-device.35255/
I looked at your post and my eyes focussed in on the relatively high distortion @400Hz, and suspected... well I didn't want to jump the gun, so I went to the ASR review, and read the first few paragraphs, and then strongly suspected what the problem was - gaps or leaks - which can be notorious to track down because they can be from anywhere. Screws not tight enough (thus vibrating), parts inside knocked loose thus vibrating (during transit shipping) etc. It usually manifests as high distortion in small bandwidth or single frequency.
references:
https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7013432
https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7013453
But I digress. That's me wearing the hat of a (amateur) loudspeaker builder/designer. I've been a member of DIYAudio since 2005, so I've been doing it for at least as long as that...
What I'm most surprised about is that this reviewer has really gone above and beyond...
When the owner was notified of the problem from the reviewer- why did he not send it back to the manufacturer, as offered, and suggested? Isn't that what warranty is for?
If you're wearing the consumer hat, isn't that your right?
If you're hearing a reviewer's hat, are you sure you should be attempting to open said product, troubleshooting and servicing it?
It's a slippery slope when you start modifying/repairing/upgrading the product you're reviewing, as evidence by the post, and 13 pages (as of today) of replies, insinuation, attacks, defence lobbied at the manufacturer, and even a previous reviewer.
Look we often discover something unusual, I'm as curious as the next guy and like to problem solve it. But I think it entirely more professional to leave it as is, And let the manufacturer respond to the review, as published. Like the way Amir does it, or Kal Rubinson or other Stereophile reviewer does it.
BROKE. Ain't fixing.
Ball's in your court.
As a consumer when I discover something unusual, I try really hard to troubleshoot and figure out what's going on. But under no circumstances do I try to open it up and fix it myself. I just take it back to the retailer, and if to no avail, I take it back to the manufacturer, to address any issues. (Most of the time, I hope I'm wrong (user error) because the alternative is long and drawn out process)
It's a shame that both owner and reviewer did not feel empowered or listened to, to have the issue addressed directly by the manufacturer. In my business that's called a breakdown in communication.
references:
https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7013432
https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7013453
But I digress. That's me wearing the hat of a (amateur) loudspeaker builder/designer. I've been a member of DIYAudio since 2005, so I've been doing it for at least as long as that...
What I'm most surprised about is that this reviewer has really gone above and beyond...
When the owner was notified of the problem from the reviewer- why did he not send it back to the manufacturer, as offered, and suggested? Isn't that what warranty is for?
If you're wearing the consumer hat, isn't that your right?
If you're hearing a reviewer's hat, are you sure you should be attempting to open said product, troubleshooting and servicing it?
It's a slippery slope when you start modifying/repairing/upgrading the product you're reviewing, as evidence by the post, and 13 pages (as of today) of replies, insinuation, attacks, defence lobbied at the manufacturer, and even a previous reviewer.
Look we often discover something unusual, I'm as curious as the next guy and like to problem solve it. But I think it entirely more professional to leave it as is, And let the manufacturer respond to the review, as published. Like the way Amir does it, or Kal Rubinson or other Stereophile reviewer does it.
BROKE. Ain't fixing.
Ball's in your court.
As a consumer when I discover something unusual, I try really hard to troubleshoot and figure out what's going on. But under no circumstances do I try to open it up and fix it myself. I just take it back to the retailer, and if to no avail, I take it back to the manufacturer, to address any issues. (Most of the time, I hope I'm wrong (user error) because the alternative is long and drawn out process)
It's a shame that both owner and reviewer did not feel empowered or listened to, to have the issue addressed directly by the manufacturer. In my business that's called a breakdown in communication.
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Jean-Claude,
Are you doing active or passive?
I wonder whether you can pre-build the box, with driver holes as specified, and fine tune later?
A ported box can always be converted to sealed, and the tuning can always be adjusted later, for the room.
I'm going with ~20L per PTT8.0X04-NAB-02... may I suggest slightly larger ~1 cu ft per PTT8.0X-08 ?
Agreed. Given that only one speaker of the pair seemed to have the problem, and the owner had not heared anything untoward it would be a back to the manufacturer Job. Doesn't help that it's easier to buy a Klippel than become an expert in speaker design as well. I fear we may be on the cusp of 'all the gear and no idea' reviewers appearing.
Shame as the happy path in this case would have been March audio finding and fixing a QA issue, leading to a positive review an a happy customer.
Rarely is a manufacturer willing to pay for the shipping to have a product returned to them for repair. I had to pay to send a Festool track saw and a Hypex power supply back for repair so it can happen with large companies. Given the speaker was in South Korea and there are import concerns it's not so unreasonable that the speaker wasn't returned.
@lrisbo what is your thoughts on the frame resonance and driver torqueing, as an email from Purifi was quoted in one of the later posts.
@lrisbo what is your thoughts on the frame resonance and driver torqueing, as an email from Purifi was quoted in one of the later posts.
I didn't create account for a few years. sorry about that.
I'm one who purchased Sointuva WG(on working), and P422 Amp(arrived today, but, I'll return to home tomorrow I can provide real photos from tomorrow).
Because I love the design of Purifi drivers and Amps, and Marchaudio's too.
Low noise and heat with amps.
Great directivity, reasonably priced(considering the ingredients!), significantly low distortion @ decent sound pressure levels and great exteriors with speakers.
Again, That's exactly why I choose Purifi and Marchaudio.
I just hope there are infinite and consistent improving of whole community. not the spit venoms on each others faces.
So, Please don't get me wrong.
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That's reasonable indication, but I'm not the owner of that samples and not the person who measured. so I do not know detailed situations of them.
I'm sorry about I can't inform you more about this.
No worries. Odd things have happened on the internet so just needed to be sure.
That distortion was known by purifi IIRC they updated the woofer frame design to rectify. All earlier models show this high Q ~400hz at certain volume levels that goes away when turned up. I have it in some measurements here I think and they also can be seen in ASRs directiva I think?
Directiva internal height is ~37cm which would make first mode around ~460Hz. I guess the Sointuva and most other ~6" two way speakers are similar in size. All that is needed is it leaking out somewhere 
Two way speakers inevitably have box modes on the pass band and the builder needs to make sure they don't make audible problem thats all. Or just make a three way speaker that deals with the modes by separation of concern.
edit. reading replies below it can be different problem than what I tired to explain here but falls into same category, a problem that needs to be dealt with somehow not to have it audible.
Two way speakers inevitably have box modes on the pass band and the builder needs to make sure they don't make audible problem thats all. Or just make a three way speaker that deals with the modes by separation of concern.edit. reading replies below it can be different problem than what I tired to explain here but falls into same category, a problem that needs to be dealt with somehow not to have it audible.
frame-motor resonance: this is a generic thing for all electrodynamic drivers. there is a heavy motor hanging in the frame which is bolted to a box. The frame acts as a (very stiff) spring and the motor is a mass thus forming a mass spring oscillator. All the Newton forces of the driver goes through this mass-spring system. This makes it very critical how the frame is fixed to the box since the high forces can cause rattling (ie high distortion).
It would be a lot better to mount the driver by its motor which is the source of the Newton forces but this is not standard. The best would be to bolt the motor onto a heavy solid chunk of metal serving as inertial reference to absorb the Newton forces.
Anyway, this is as mentioned a generic problem for all drivers but with the X stroke PTT drivers we have high Mms and a very strong motor in order to get low F3 in a compact box and this means the driver produces more Newtons force for the same SPL compared to a lower Mms driver. This makes the mounting method more critical including how much torque and what materialsused etc.
When measuring on the driver laying on its magnet the problem is gone since the Newton forces terminate into the 'ground'and the frame is untermintaed so we do not have the mass-spring oscillator.
It would be a lot better to mount the driver by its motor which is the source of the Newton forces but this is not standard. The best would be to bolt the motor onto a heavy solid chunk of metal serving as inertial reference to absorb the Newton forces.
Anyway, this is as mentioned a generic problem for all drivers but with the X stroke PTT drivers we have high Mms and a very strong motor in order to get low F3 in a compact box and this means the driver produces more Newtons force for the same SPL compared to a lower Mms driver. This makes the mounting method more critical including how much torque and what materialsused etc.
When measuring on the driver laying on its magnet the problem is gone since the Newton forces terminate into the 'ground'and the frame is untermintaed so we do not have the mass-spring oscillator.
Mainframe,
yeah I’ve noticed it in my drivers way about 12 months ago too. I too was curious and and found it had existedin Rick Craig’s Purezza too:
My own measurements are somewhere in this thread DIYaudio a few dozen pages back, but I thought it best not to drag it up just now, hoping not to derail the thread.
My point is, for the record, and for people who haven’t had a chance to read the entire spiel; it’s not the drive unit. It’s a gap or leak somewhere in the entire loudspeaker causing rattle/rub/fuzz manifesting as “distortion”
It seems to me, that what the manufacturer suggested early on in email response can only be considered speculation. Like “yeah It could be the frame”. But it could be the venting in the cone behind the dust cap, it could well be… any manner of things.
But Nothing has been verified because the unit has not been returned for testing.
Now i also get fluid, but I think if you have a direct-to-consumer business model, then you better have a solution for when things arrive in anything less-than-perfect condition.
And as a consumer purchasing from a direct-to-consumer business, (or online) well, then you also need to have a solution for when things arrive in a less than perfect condition, and you don’t have a local retailer to talk to.
Like, “yeah, I wanna send it back, but I’m worried about the high cost of shipping”
There are many RTB models employed in business; and put neither the consumer or manufacturer out. It’s a win-win.
All I see in this unfortunate situation is a lose-lose.
And, for the record, for people who haven’t had a chance to read the entire spiel; it’s not the driver.
yeah I’ve noticed it in my drivers way about 12 months ago too. I too was curious and and found it had existedin Rick Craig’s Purezza too:
My own measurements are somewhere in this thread DIYaudio a few dozen pages back, but I thought it best not to drag it up just now, hoping not to derail the thread.
My point is, for the record, and for people who haven’t had a chance to read the entire spiel; it’s not the drive unit. It’s a gap or leak somewhere in the entire loudspeaker causing rattle/rub/fuzz manifesting as “distortion”
It seems to me, that what the manufacturer suggested early on in email response can only be considered speculation. Like “yeah It could be the frame”. But it could be the venting in the cone behind the dust cap, it could well be… any manner of things.
But Nothing has been verified because the unit has not been returned for testing.
Now i also get fluid, but I think if you have a direct-to-consumer business model, then you better have a solution for when things arrive in anything less-than-perfect condition.
And as a consumer purchasing from a direct-to-consumer business, (or online) well, then you also need to have a solution for when things arrive in a less than perfect condition, and you don’t have a local retailer to talk to.
Like, “yeah, I wanna send it back, but I’m worried about the high cost of shipping”
There are many RTB models employed in business; and put neither the consumer or manufacturer out. It’s a win-win.
All I see in this unfortunate situation is a lose-lose.
And, for the record, for people who haven’t had a chance to read the entire spiel; it’s not the driver.
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Hi
This is Alan March. This is an old account which I havent used for a long time hence the user name. I will get it updated ASAP or create a new one.
The problem we have here is that the reviewer, who appears not to be the owner, has drawn erroneous conclusions and ignored all the information I have previously fed back to him (through another S Korean forum member). I specifically covered the resonance issue, how it appears almost identically in every single other measurement of speakers based on this driver even though they are different shapes and sizes, and of Purifis comments.
Unfortunately he has decided that his conclusions are correct (caused by leaks and lack of speaker fill etc) and gone public with them. As such we are forced to reply and defend our reputation against this misinformation. He did so in ASR where I have no direct right to reply.
So in my view "all the gear and no idea" is quite an apt description. Unfortunately it is a fundamental problem of the internet where everyone has an opinion which they believe is more valid than anyone else's.
We indeed screwed up by not sealing the binding posts and have corrected the manufacturing procedure to make sure it does not happen again. The issue was not picked up on our production tests as we use very tight fitting banana plugs which sealed the hole. The owner was happy with and accepted the compensation we gave him to account for his time to rectify and seal the post. Our mistake, we owned it and sorted it.
The reviewer has obviously dismantled and re-assemble the speaker multiple times. He was ignorant of the necessary procedures and specifications for doing this. He has also modified its wiring from the manufactured state and posted misleading pictures of how this wiring was arranged at manufacture. He has removed the speaker fill material and pulled the wiring from its manufactured position.
As such we (and I suggest others) can only treat his other statements with abundant caution. We also cant be responsible for his technical ignorance.
Its a shame things end up like this and manufacturers have to waste time defending ourselves against self appointed internet "arm chair experts", but I feel it is important that a balanced technical view should be presented to the audio community. Members of the community need to be very wary of the opinions offered by many online reviewers.
Alan
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