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Research Project: Infinity IL10 Speaker Review & Measurements

Vuki

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Nope. Break-up doesn't even make distorsion. It does nothing, except a change in linear response aka amplitude frequency response. Only if the AFR is exaggerated, by the diaphragm breaking-up in resonance, that amplifies distortion products, which are generated elsewhere (!) in the frequency range.

Many drivers happily take advantage of break-up, to everybodies pleasing, while keeping HD at very low level.

The said effect of HD/IM amplification wasn't recognized, or communicated the least, when the stiff cone tech came up, like hexacone, metal and so on.
The advertizing claimed that in particular soft cones where susceptible to HD/IM due to lacking rigidity. The other way round it was. The common resonance(s) of the stiff cones were excited by distortion products and generated a specific signature, which, sure enough, was taken as supernatural clearity. It is not so, that the HD was experienced as THE second or THE third harmonic. Due to the resonance it would be perceived as an up- and down-swelling side note of fixed frequency. Of course such an effect would be pronounced if at exactly that frequency the resonance appears as a peak in the AFR too. It would render the affected frequency band a focus of attention, which was not set by the music, but by the speaker.

If not damped (mechanically or electrically) hard cone driver brake-up rings/resonates and I would like to see one use this effect with good result.
 

patate91

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If not damped (mechanically or electrically) hard cone driver brake-up rings/resonates and I would like to see one use this effect with good result.

Does cone breakup reasonance should be seen in waterfall graph? *(Edit In FR as well)

Except for ~1,5khz there's no significant resonnance.
 

tuga

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I don't understand, can you explained what you said?

The vertical scale (dB) is too narrow (Stereophile's is 36dB wide).

Also it would help if the mid-woofer were to be measured solo, like this:

1190M10fig06.jpg

https://www.stereophile.com/content/monitor-audio-studio-10-loudspeaker-measurements
 

patate91

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You would have to ask for that to Stereophile editors...

I talking about the scale of Amir's measurement.

Resonnance should show up in waterfall graph. Is the scale prevents it, someone can just change the scale
 

NTK

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The analogy doesn't fit, as is often the case. The 'break up' doesn't indicate a broken (whatever). All the consequence You mention is actually not present.
It depends on what you mean by broken. If you mean irreversible damage, then broken-up diaphragm doesn't mean broken diaphragm. Something that has buckled, if the material did not exceed its elastic limit, can return to its original shape and no permanent harm is done. If it refers to the ability to retain its performance specifications, then yes, it is broken.

Nope. Break-up doesn't even make distorsion. It does nothing, except a change in linear response aka amplitude frequency response. Only if the AFR is exaggerated, by the diaphragm breaking-up in resonance, that amplifies distortion products, which are generated elsewhere (!) in the frequency range.
Break up doesn't need to cause distortions (the nonlinear kind) for its detrimental effects to be felt. It wreaks havoc to the frequency response, which is the more audible kind of defects, as you have said.
 

GelbeMusik

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It depends on what you mean by broken.

You said:

"A broken up diaphragm can lead to a very bad case of IM distortions. Once the diaphragm is broken up (i.e. gone into buckling), it destroys its performance for all other frequencies because the diaphragm stiffness is gone. The change in the stiffness can be understood using a structural column as analogy."

I think it was quite fair to correct this common, but utterly wrong statement, which is based on an misunderstanding regarding the analogy, I assume.
 

KaiserSoze

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The amount of hostility on this user-participation site is somewhat excessive. Too many people are too eager to be critical of something that someone else wrote, and are not taking time to think through how to phrase criticisms in a polite way that will not engender a defensive reaction.

One other thing I want to point out is that it is the nature of Amir's chosen task to be critical of gear. This is not at all the same thing as criticism of another person or of what another person wrote, and as such there is a completely different standard for civility. I wanted to point this out before writing this:

The level of distortion at about 1.5 kHz is strong enough such that it will most likely be audible to people who are sensitive to distortion, who may be bothered by it, depending on various factors to include especially the volume level at which the speaker is being played. This level of distortion is significantly greater than with other speakers of similar design and that otherwise exhibit similar measured behavior.

No one ought to take exception to something worded this way, but the question we have to ask ourselves is whether it reasonable to expect Amir to tiptoe gently through the tulips every time he finds something he doesn't like in a speaker. The answer is no, it isn't reasonable. He's writing about equipment, not people. If you disagree with one of his conclusions or statements, then think about your reason long enough such that you won't have to write follow-ups to explain or justify your argument. Then post it, one time and one time only, and then step away from it. You're done. It would have been sufficient for someone to have written something like, "That distortion peak isn't likely so strong that everyone will hear it and be bothered by it." Or even, "The empirical data related to the audibility of distortion isn't sufficiently absolute to permit anyone to say with certainty that the distortion peak at 1.5 kHz will be audible to the Average Joe." Yes, it is appropriate to say something like this, but only if stated once, not repeatedly. And no, my dog does not bite.
 

mjwin

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Whitebox testing would focus on the resonance of the suspension, and test the deformation by simultaneously reproducing bass. Sometimes the IM is acceptable, sometimes not.
I think this could be a very interesting test. It would a labour intensive operation to first find the resonant point, and then simultaneously apply an additional tone, or swept tone. Not easy to incorporate into an ASR style test routine, but more the sort of thing which manufacturers should be doing. And, publishing their results...
The popular nasty multitone story hardly reveals an effect, because the disturbance barely gets above the background noise. But with a thinned out signal the case becomes immediately noticeable. Also for the hearing.
You have a very valid point here. When I was thinking about using a form of multitone as the test signal, I felt that it would stress the speaker by injecting a lot of energy which, of course, it will. But the energy is spread out over the whole spectrum and very little will go into exciting the resonances. As you suggest, two carefully chosen tones would be far better.
The by now well known bass driver SB Acoustics 17NAC of Revel / Burchardt fame shows this behaviour of course, too, but very well damped. Another one at 6 times the price has chosen a way less damped "lowest loss" suspension, which keeps the HD part extremely low, but the generated IM spreads over a remarkably wide frequency range once the right tones are hit, and thus becomes disturbing.
ASR's resident expert on driver testing, @hardisj, might have some experience of this, I think...
 
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Robbo99999

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The amount of hostility on this user-participation site is somewhat excessive. Too many people are too eager to be critical of something that someone else wrote, and are not taking time to think through how to phrase criticisms in a polite way that will not engender a defensive reaction.

One other thing I want to point out is that it is the nature of Amir's chosen task to be critical of gear. This is not at all the same thing as criticism of another person or of what another person wrote, and as such there is a completely different standard for civility. I wanted to point this out before writing this:

The level of distortion at about 1.5 kHz is strong enough such that it will most likely be audible to people who are sensitive to distortion, who may be bothered by it, depending on various factors to include especially the volume level at which the speaker is being played. This level of distortion is significantly greater than with other speakers of similar design and that otherwise exhibit similar measured behavior.

No one ought to take exception to something worded this way, but the question we have to ask ourselves is whether it reasonable to expect Amir to tiptoe gently through the tulips every time he finds something he doesn't like in a speaker. The answer is no, it isn't reasonable. He's writing about equipment, not people. If you disagree with one of his conclusions or statements, then think about your reason long enough such that you won't have to write follow-ups to explain or justify your argument. Then post it, one time and one time only, and then step away from it. You're done. It would have been sufficient for someone to have written something like, "That distortion peak isn't likely so strong that everyone will hear it and be bothered by it." Or even, "The empirical data related to the audibility of distortion isn't sufficiently absolute to permit anyone to say with certainty that the distortion peak at 1.5 kHz will be audible to the Average Joe." Yes, it is appropriate to say something like this, but only if stated once, not repeatedly. And no, my dog does not bite.
Really......? Well thankyou for that post (I guess).
 

GelbeMusik

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I think this could be a very interesting test. It would a labour intensive operation to first find the resonant point, and then simultaneously apply an additional tone, or swept tone.

ASR's resident expert on driver testing, @hardisj, might have some experience of this, I think...

Hm, I'm proud to say, that my experience goes as far. I do such tests regularly, and I'm happy to tell You, that as a designer of multiway loudspeakers, I'm quite aware of the typical problems of bare drivers. So, to set up a white-box test, if You want to call it like this at all, is very easy. But, admittedly it cannot be done automatically. And reiterated, I personally don't seem to need it.

Mostly one has only limited choice regarding the drivers. To compare like three or so regarding common weak points is actually straight forward. Would I trade a narrow problem zone with extremely low HD but broad IM spectrum against a bit higher, still subliminal HD and narrow IM spectrum throughout? You guess ;-) Me too 8-( Both alternatives would be actually a valid "best You can get" choice. Getting used to the cognitive dissonance ...

What I'm really curious about is my wild speculation (!) regarding the excitation of resonances by HD/IM, especially when driven hard. And the emphasis this effect may undergo with corresponding peaks in amplitude frequency response, as is explicitly seen here with the IL-10. That such irregularities, linear or not are attractors to the hearing, and by that distractors?!?

Alas, another project on this board, a distortion generator fell into some kind of a deep sleep, so there is no real use in asking for an according addition to its feature set.
 
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amirm

amirm

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Speaking of which, we don't have any multitone tests because that feature wasn't included in the license, right?
Correct. It is 1,900 euros. I can use another measurement system to do it for free but it is work. :)
 

Thomas savage

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Going forward in this thread there will be thread bans for repetitive arguing that brooches obsessive harassment and isn't constructive .

This has all got a bit bad tempered, there's so many pages and very little of it is really moving things forward .
 

Robbo99999

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In retrospect you could label that post of mine as unnecessary. Feel free to do that and to do likewise with this post. But if you do, be sure to point out that your post was devoid of any value whatsoever, except possibly to someone who assigns strong value to low-grade sarcasm.
Indeed! (I couldn't resist the general level of pomposity to which I replied, I am sorry for that.)
 

617

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Going forward in this thread there will be thread bans for repetitive arguing that brooches obsessive harassment and isn't constructive .

This has all got a bit bad tempered, there's so many pages and very little of it is really moving things forward .

Agreed. My attitude; no data, nothing to talk about.
 

tuga

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Agreed. My attitude; no data, nothing to talk about.

Ways of gathering data (both through observation and by measuring)?
 
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