Is there cabinet vibration at 380-400 Hz? Just feeling with the hand could reveal this.
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The REAL Problem of March Audio's Sointuva WG (Review, Measurements and Reinforcements with Klippel device)
- Thread starter Nuyes
- Start date
Is there cabinet vibration at 380-400 Hz? Just feeling with the hand could reveal this.
KxDx
Senior Member
As an American, this made me chuckle.
Directiva r1 is based on a Denovo flatpack with internal dimensions of 36.8 cm, where first height mode would occur at 466 Hz. But the measured resonance is below 400 Hz, why this is not likely the cause.
Also, @mdsimon2 got eagle’s eyes, very good!
You mean standing waves in cabinet? I was more into modal vibrations of the cabinet walls. These are quite complex to accurately calculate, but can be quite easily felt by hand if you do not have an accelerometer at hand. Excitation can be from standing waves or from mechanical resonance of the motor-driver-assembly.
Sokel
Master Contributor
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Almost every smartphone has accelerometer but I think that's not the case here.
You must fasten the sensor to get accurate readings. These
can be had quite cheap.
Well @Nuyes is not unit reviewer and I'm not reveiwer to begin with so further testing will not be easy I think... Better wait for @DualTriode 's in-depth test I guess.
Exactly. This Toni Mas guy is a complete troll. If you don’t believe in measurements WTF are you even
doing here?
Go back to subjective lala land.
The hubris and lack of humility by Alan March is astounding.
Who do people trust and like the most?
Data from similarweb - total visits to website in the last month:
AudioScienceReview.com - 2.4M
ErinsAudioCorner.com - 42.1K
MarchAudio.com - 15.2K
I am currently building a website for an artist friend, and easy navigation and simple and logical paths to find things are a primary goal for me. AudioScienceReview is a big, complex website, but I find navigation here quite easyn and logical here.
I like Erin and his reviews, but I see his website as poorly designed. It is not visually attractive, and there is neither a review index or search box available. Improving the visual appeal of his website would attract more views, and perhaps increase his internet income and donations. Then he wouldn't feel the pressure to use other websites to promote his own site.
OTOH, I find Alan's March audio website to be quite attractive and easy to navigate. His Sointuva speaker page is very nice, and if it were in my price range, I would be very tempted by that loudspeaker. I also like how they look - it reminds me of my current budget loudspeakers, the Wharfedale D320s with their rounded corners.
I buy cheap Chinese audio components to play with and use on my desktop, and I even have a 30 lb. Yarland EL34 Class A PP amp that cost me over $1k by the time I received it here in Panamá. The cheap stuff from halfway round the world with no possibility of free or low cost warranty support is "throw-away" gear for me. If it lasts a year or two before failing, I don't get upset. Tube amps are relatively simple and easy to repair, so I wasn't worried about the Yarland company being so far away - and actually, the company's web presence is gone and they likely have gone out of business.
However, with expensive SOTA (state of the art) high-end made to order components like the Sointuva speakers with their esoteric Purifi drivers, I would expect them to be thoroughly tested and work perfectly. I know and like Alan March from earlier interactions on ASR forums as well as off-line conversations. Many years ago, as a "sales engineer" in super-precision bearings rotating components for aerospace applications (including the Hubble space telescope), the company I worked for had incredibly rigorous quality control, and Alan was involved in similar aerospace environment - in vibration control and testing! His aerospace engineering background also included incredibly rigorous quality control. I was surprised to learn that a pair of his loudspeakers went to Korea with such oversights and problems. Apparently the problms have now been sorted out, and in spite of the contentious back-and-forth interactions on the path to resolution, I still think that March Audio products overall are excellent.
It is unfortunate that the path to understanding and resolution was so nasty at times. But that is what happens when alpha males with type A personalities screw up and can't handle criticism with logic and grace. Quite frankly, I would be happier if things had not gotten out of hand, and Erin and Alan were still active ASR participants.
Data from similarweb - total visits to website in the last month:
AudioScienceReview.com - 2.4M
ErinsAudioCorner.com - 42.1K
MarchAudio.com - 15.2K
I am currently building a website for an artist friend, and easy navigation and simple and logical paths to find things are a primary goal for me. AudioScienceReview is a big, complex website, but I find navigation here quite easyn and logical here.
I like Erin and his reviews, but I see his website as poorly designed. It is not visually attractive, and there is neither a review index or search box available. Improving the visual appeal of his website would attract more views, and perhaps increase his internet income and donations. Then he wouldn't feel the pressure to use other websites to promote his own site.
OTOH, I find Alan's March audio website to be quite attractive and easy to navigate. His Sointuva speaker page is very nice, and if it were in my price range, I would be very tempted by that loudspeaker. I also like how they look - it reminds me of my current budget loudspeakers, the Wharfedale D320s with their rounded corners.
I buy cheap Chinese audio components to play with and use on my desktop, and I even have a 30 lb. Yarland EL34 Class A PP amp that cost me over $1k by the time I received it here in Panamá. The cheap stuff from halfway round the world with no possibility of free or low cost warranty support is "throw-away" gear for me. If it lasts a year or two before failing, I don't get upset. Tube amps are relatively simple and easy to repair, so I wasn't worried about the Yarland company being so far away - and actually, the company's web presence is gone and they likely have gone out of business.
However, with expensive SOTA (state of the art) high-end made to order components like the Sointuva speakers with their esoteric Purifi drivers, I would expect them to be thoroughly tested and work perfectly. I know and like Alan March from earlier interactions on ASR forums as well as off-line conversations. Many years ago, as a "sales engineer" in super-precision bearings rotating components for aerospace applications (including the Hubble space telescope), the company I worked for had incredibly rigorous quality control, and Alan was involved in similar aerospace environment - in vibration control and testing! His aerospace engineering background also included incredibly rigorous quality control. I was surprised to learn that a pair of his loudspeakers went to Korea with such oversights and problems. Apparently the problms have now been sorted out, and in spite of the contentious back-and-forth interactions on the path to resolution, I still think that March Audio products overall are excellent.
It is unfortunate that the path to understanding and resolution was so nasty at times. But that is what happens when alpha males with type A personalities screw up and can't handle criticism with logic and grace. Quite frankly, I would be happier if things had not gotten out of hand, and Erin and Alan were still active ASR participants.
Similar thought here, I liked ASR but also liked Erin's review with similar approach, it's always good to have another source for data and discussion with similarly reliable data.
And I would say I even notified some of my friends who like to buy a pair of Hifi Speakers the Sointuva when being asked for recommendation, impressed by the degree of flatness and directiviy achieved in passive design and it's look. Personally I don't care about monetization for Erin as it's ppl's choice to support or not, also it's perfectly fine for Amirm to have his own rules about the issue in his place, so both Amirm and Erin gets my respect.
But I have to emphasis Alan did lost my "nobody" confidence, as his early release and design phase posts really gave me huge hope for the Sointuva, but this issue in the post, being able to easily be solved by simply openly take the speaker back, send in a pair of good QC quality speaker (supposed it's not design miss) was taken into an defensive arguement. I have no idea about who's correct between the OP and Alan about the screw torque issue, but I think it would be wise to disclose the screw torque value for users to DIY, as after this review by OP I bet other customers would like to take out the speaker driver and treat the seal, which if I am not mistaken involving taking apart the drivers, which according to Alan, just tightening it will result in distortion issue.
OP
- Thread Starter
- #516
Here is a bolt torque comparison test.
This is one of the things many of you have been wondering about.
"Is it true that it changes with the degree of torque on the bolt? If so, how much?"
After an A/B comparison test, the speaker owner gave me Alan's message.
"Did you overtighten the bolts?"
Of course it wasn't.
Because I didn't do any manipulations without the permission of the speaker owner.
And at the time we knew Alan was the supreme authority on this speaker and its knowledge, so we did as directed.
I tightened the woofer, passive radiator and tweeter assembly.
Anyway, here are the results.
We can definitely notice an increase in 3rd harmonic distortion at 380hz.
Let's compare the two data by overlapping them.
Alan and Purifi were right.
However, the peak is about -65dB.
Of course, I'm not saying this doesn't affect the condition of the speakers.
First, let's move on to
Nearfield measurement of passive radiators.
Let's compare the two data by overlapping them.
Can you spot any significant differences?
Did I break the speaker? using bolts?
I admit the facts about 380hz among your comments.
Tightening the screwdriver strongly may increase distortion.
But, at least in my experiments, it was way too small.
You are right.
You sent your speakers in 'perfect' condition.
But I tightened the volts arbitrarily, and it boosted the driver's 3rd harmonic distortion to -65dB (5V) level.
If so, I ask again.
Why do your 'perfect' speaker shows more than 1% harmonic distortion at 85dB SPL at 1m?
This is one of the things many of you have been wondering about.
"Is it true that it changes with the degree of torque on the bolt? If so, how much?"
After an A/B comparison test, the speaker owner gave me Alan's message.
"Did you overtighten the bolts?"
Of course it wasn't.
Because I didn't do any manipulations without the permission of the speaker owner.
And at the time we knew Alan was the supreme authority on this speaker and its knowledge, so we did as directed.
I tightened the woofer, passive radiator and tweeter assembly.
Anyway, here are the results.
We can definitely notice an increase in 3rd harmonic distortion at 380hz.
Let's compare the two data by overlapping them.
Alan and Purifi were right.
However, the peak is about -65dB.
Of course, I'm not saying this doesn't affect the condition of the speakers.
First, let's move on to
Nearfield measurement of passive radiators.
Let's compare the two data by overlapping them.
Can you spot any significant differences?
Did I break the speaker? using bolts?
I admit the facts about 380hz among your comments.
Tightening the screwdriver strongly may increase distortion.
But, at least in my experiments, it was way too small.
You are right.
You sent your speakers in 'perfect' condition.
But I tightened the volts arbitrarily, and it boosted the driver's 3rd harmonic distortion to -65dB (5V) level.
If so, I ask again.
Why do your 'perfect' speaker shows more than 1% harmonic distortion at 85dB SPL at 1m?
OP
- Thread Starter
- #518
No, It's not a relative data.
It seems that it may be some minor difference in the level of fundamental also. Which can be expected.
OP
- Thread Starter
- #520
Yes, that's right.
Since they are not measured on the same date, even near-field measurements may cause slight differences in Fundamental SPL.
This is due to the distance between the microphone and the diaphragm.
But nevertheless, we can find the 3rd HD peak at 380hz particularly emphasized.
I'm sure this is a common characteristic of Purifi described by Alan.
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