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The REAL Problem of March Audio's Sointuva WG (Review, Measurements and Reinforcements with Klippel device)

AdamG247

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The personal comments are getting awful aggressive. Please dial it back. Happy Friday and happy 4th of July to those of you that celebrate. Thank you for your understanding.
 

puppet

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With regard to the bolt torque ... it could be that the bolts may have been tightened equally upon assembly. Mother Nature may have also acted on the dimensions of the baffle(s), hole diameter(s) affecting the final torque. Relative humidity and wood are a bitch.
 

beren777

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You've actually never assembled, dismantled or ever tested a loudspeaker have you?

March's BS knows no bounds. He will attempt to blame anyone, everyone he can, instead of owning up and dealing with it.

I have assembled, dismantled, and tested a loudspeaker on two occasions, both very poorly in terms of woodworking, painting, testing method, and basic application of wood glue.

Purifi is on record stating there is an issue with the driver. The manner in which the woofer is secured to the speaker body impacts the manifestation of the issue. March Audio states that it's part of how they are addressing the issue. In this case, torque is pertinent to the discussion.

aliens-alien.gif
 

puppet

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If torque is an issue then a threaded insert should be used instead on the baffles.
 

flyhigh

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I have assembled, dismantled, and tested a loudspeaker on two occasions, both very poorly in terms of woodworking, painting, testing method, and basic application of wood glue.

Purifi is on record stating there is an issue with the driver. The manner in which the woofer is secured to the speaker body impacts the manifestation of the issue. March Audio states that it's part of how they are addressing the issue. In this case, torque is pertinent to the discussion.

aliens-alien.gif

Alan asked to the owner to dismantle the speaker to repair the leaky binding posts.
If the torque is that important, he should provide exact torque values to the owner for repairing binding post.
But he did not mention the torque values to the owner.
 

sq225917

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Jesus just tighten until they all nip up, wildly different bolt tensions are easy to feel by hand.

Personally I don't like the whole thread; hosting off site, negative reviews, that could be seen as a hatchet job by people of certain opinions, on a site where the brand owner is banned is an ugly look.

Amir's free to do what he likes, but it just gives fuel to the fire for anyone looking to taint this site's reputation. I get that uts a nice technical review, but the big picture isn't a good look.
 

beren777

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For reference, quoting Irisbo from diyaudio:


"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."

Alan asked to the owner to dismantle the speaker to repair the leaky binding posts.
If the torque is that important, he should provide exact torque values to the owner for repairing binding post.
But he did not mention the torque values to the owner.

So are you saying that it doesn't matter, or that Alan provides poor customer service?

Alan's quoted elsewhere earlier in this thread stating that he considers the mitigation methods proprietary, that he doesn't want to disclose the methods, and asks if the bolts were tightened as he says that will impact distortion.
 

sq225917

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So purifi admit the motor frame is underbuilt...
 

flyhigh

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For reference, quoting Irisbo from diyaudio:


"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."



So are you saying that it doesn't matter, or that Alan provides poor customer service?

Alan's quoted elsewhere earlier in this thread stating that he considers the mitigation methods proprietary, that he doesn't want to disclose the methods, and asks if the bolts were tightened as he says that will impact distortion.

Alan provides very poor customer service and poor QC control of his products, for sure.

When the owner communicated with Alan,
Alan did mention that adjusting torque might solve the problem, but never mention the exact torque number.

Additionally, OP tried different torques.
OP knew that, by his distortion measurements stonger torque made distortion higher, but adjusting torques did not eliminate the problem.

Furthermore, one of the bolts were not assembled at all, despite the importance of the torque!
 

Absolute

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I read all 4 parts of Alan March’s post there, and I respectfully disagree with your assessment. There are definitely a couple of moments of “excess heat” in March’s statement, and at least one claim he makes about Amir’s testing methods is simply false (that Amir supposedly doesn’t test amps for load dependence).

But most of what he says is clearly presented and well-argued. In particular, he appears to be completely right about the driver-resonance issue. He might be wrong on some counts, and I don’t dispute that he’s shown a temper online that got him banned here. But IMHO his explanations on this matter are in no way, shape, or form a “bad look.” Quite the contrary.
The whole thread and posts he makes has a vindictive tone. Not a great look for a professional manufacturer and/or salesman.

I genuinely don't care what happened or who's right or wrong. We all make mistakes. To be honest this person-focus around ASR is really off-putting.
 

beren777

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Alan provides very poor customer service and poor QC control of his products, for sure.

When the owner communicated with Alan,
Alan did mention that adjusting torque might solve the problem, but never mention the exact torque number.

Additionally, OP tried different torques.
OP knew that, by his distortion measurements stonger torque made distortion higher, but adjusting torques did not eliminate the problem.

Furthermore, one of the bolts were not assembled at all, despite the importance of the torque!

The quote from March Audio in post #2 wasn't asking the owner to tighten anything in hopes of solving a problem. By my reading, Alan was curious whether the owner had tightened them already and that doing so might cause a problem.

We don't know that it left March Audio in that state, but I agree their QC should check it prior to shipping if it's a critical design point.
 

tmtomh

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The whole thread and posts he makes has a vindictive tone. Not a great look for a professional manufacturer and/or salesman.

I genuinely don't care what happened or who's right or wrong. We all make mistakes. To be honest this person-focus around ASR is really off-putting.

Again, I respectfully disagree. There are definitely moments in Alan's posts there where I would agree with you, but I would not say the whole thing has a vindictive tone - and most importantly, I would further say that his tone is notably less ad hominem and less vindictive than much of the discussion in this thread.

I do totally agree with you that the person-focus is the problem. My claim is simply about how we are assessing who is and is not sounding vindictive or who is and is not making ad hominem attacks.

And I also do care who's right or wrong, not because of the "who" but rather because of the "right" and the "wrong" - I think it's interesting and useful to suss out what the actual facts are so we can learn. (I'm sure you agree with that general idea too - so I don't mean to misrepresent you here.)
 

YSC

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The quote from March Audio in post #2 wasn't asking the owner to tighten anything in hopes of solving a problem. By my reading, Alan was curious whether the owner had tightened them already and that doing so might cause a problem.

We don't know that it left March Audio in that state, but I agree their QC should check it prior to shipping if it's a critical design point.
maybe a communication problem, but what I see from both here and March's post he seems asked the owner to seal the binding post for himself/agreed the owner to do so, by then not providing specific torque setting for thte woofer seems odd, it lookse like it need to be accessed by removing the drivers anyway? So far the only issue confirmed is the lack of sealing of the binding post, which is definitely design/QC issue if it wasn't overlooked during the design phase. now then the distortion problem don't really bugs me even if the OP claimed was true (which seems not the case now?) I just wonders if the resonance issue is so important, wouldn't it make more sense to build it using some metal to build it and get a porper torque recommendation? wood/ MDF likely age/degrade through time easier compared to say aluminium
 

Xulonn

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I just wonders if the resonance issue is so important, wouldn't it make more sense to build it using some metal to build it and get a proper torque recommendation? wood/ MDF likely age/degrade through time easier compared to say aluminum
I will patiently wait for a cast aluminum version of the Sointuva Loudspeaker - sounds like a great idea.

images.png

Aluminum Speaker Enclosure.jpg
 

goat76

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Let's leave all the technical issues aside.

Again, I do not disassemble speakers without anyone's permission.

I've measured 80 speakers so far received from an anonymous sponsor.

I've never disassembled anyone else's speakers, and the Sointuva WG is my first case.
Even that, after A/B testing, Alan didn't have a proper response, so this is the speaker's owner's choice.

Alan says it's all my fault.
However, we know that a normal-minded person will not disassemble other people's objects without permission.


And something has become clear.
It's a binding post's leakage.

Did Alan properly thank the reviewer for pointing out the manufacturer's flaws and mistakes?


As a commonsense manufacturer, it is right to thank the consumer for notifying the defect with an apology.
I’m not saying I don't believe you, I’m just pointing out that Alan has no chance to share his view on the matter, due to his ban from this forum.
That's the thing that makes all this very “one-sided”.

I don't know everything about your email conversations with Alan, you have not shared the complete correspondence between you and him, as you mentioned earlier. It's possible Alan was too defensive and maybe he wasn’t thankful enough for your findings, without all the information I can’t know?

And the following has nothing to do with you, but it seems like some people here got a grudge against Alan because of things that have happened in the past. Things that got nothing to do with your findings of this speaker. That's why I think people should read what Alan got to say about it all and after that form their opinions about the whole thing.
 
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Sokel

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I know nothing about the beefs here,or who Alan and every Alan is,what I know from both sides is the a costumer got something with a flaw.
It doesn't matter if it's a divine or crap product,it doesn't matter if the flaw is minor or a catastrophe,it doesn't matter the background and the expertises of the engineer,what matters is a disatisfied client.
This Alan guy must have learned by now that he doesn't sell speakers,amps,etc.
First and most of all it sells himself like every merchant.
Clearly he doesn't know how to do it properly.There is a reason that good companies are the ones with the good marketing witch is a completely another field of expertise.
It's sad cause the product looks promising.
 

Xulonn

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There is a reason that good companies are the ones with the good marketing witch is a completely another field of expertise.
It's sad cause the product looks promising.
Well stated, @Sokel. Engineers and techies who don't like the structure and demands of working for other companies, and who try to start their own businesses, often fail because of their poor people, P.R and marketing skills. A prime example of a business partnership that avoided these pitfalls is Apple Computer, where marketing genius Steve Jobs enlisted tech wizard Steve Wozniak and created a global giant that is still going strong 46 years later.
 
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