Actually no – CMP concept is not about *improvements* first hand – it's about understanding of *limitations in current audio thinking* – that's obviously the main reason why it "sells" so badly - no quick cash to make...
🙂
Your statements again "prove" that you haven’t done meditation as suggested, hence not gotten the point about CMP concept at all...
😀
##################
But – to possibly demonstrate a practical example regarding CMP at hand of the isobaric / compound system brought up in this thread:
*If* we take an ideal compound setup, the "air spring" in the chamber between the two drivers would not have any effect – seen in the usual way (leaving different loading aside for a moment).
Looking at the system from a point of view that takes CMP behaviour into account though – you immediately become aware that the time of flight between the two diaphragms – the delay – makes it a pronounced CMP system.
The "beat" occurring from thereof is easily heard (depending on specific design), though missed by many.
John's page/ investigation into isobarics is telling us a lot of good and valid points – but – its only "half the truth" (the one that does not need "time domain thinking" 😉 ), as those CMP related effects mentioned would also occur if an "isobaric open baffle" arrangement would be analysed – hence both speakers would face identical load.
And to finally come back to Joachims's argument that he does not plan to use the isobaric into the midrange – well great – but sorry – wrong put again :
the most obvious beat of the Linn Sara is in the lower department (again - depends of course of the specific make)
🙂
Michael
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Possibly "hard to understand" for the time-domain-thinking-novice - 😀 - but I guess "relevance" you can only judge if you already have understood what's being discussed
😉
Michael
Basically glueing the two cone together. Isn't that the same as one driver with a parrallel set of parameters? That is how I have always thought of isobaric.
To me thats the deffinition of operating range, yes.
All speakers will see crossover distortion and it is the most audible of all typical forms on nonlinearity thats why it is so critical to sort out, but yes, the higher the efficiency of the speakers the more they tend to operate at the lowers levels where this distortion is present.
Actually you can. At least with the radial modes which have no azimuthal variation, which is really what George is referring to. I don't know that you would want to, and I don't know how successful it would be in practice, but in theory you can.
I've been doing some measurements and looking at data. What is going to happen next is first some listening to different sets of EQs to see what difference can be heard, they will be the scored in the order of preference, then measured to see if there is any similarity in trend with listening preference. Hope to have more to share soon.
John, that is what I felt was happening when Joachim mentioned their digital EQ improved damping. However, it take lots of effort to find out if feedback into the amplifier causes more or less degradation that the diaphragm itself. Actually, this would be a nice research for students.
John, that is what I felt was happening when Joachim mentioned their digital EQ improved damping. However, it take lots of effort to find out if feedback into the amplifier causes more or less degradation that the diaphragm itself. Actually, this would be a nice research for students.
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I never though there was any limit in audio thinking. Perhaps there is a more common trend of application. That is all. Whatever you call that thing, your description is basically a result of traveling waves. You might think that's new, good for you. You learned something. However, if you cannot use what you have learned to improve anything, I personally think it's a waste of time. It's like meditating until you die.
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Thank you Dr Geddes.
Some of us car audio guys are following this thread and applying concepts where we can...as best we can.
Some of us car audio guys are following this thread and applying concepts where we can...as best we can.
An externally hosted image should be here but it was not working when we last tested it.
You can also replace "reflection(s)" with "source(s)" and it should read "a sufficient condition for A to be MP...."
Note this is sufficient, not necessary. That is, if the condition is met A will be MP. BUt there acan be cases where this condition is not met and A will still be MP.
Dear Michael,
from my understanding all your "CMP" effects are simply consequencies of the finite speed of sound (in air or any other concerning material). Absolutely nothing new with that. 🙄
If you feel the need to do something about "CMP", you probably have to raise the speed of sound beyond our limit of perception. When you have found a solution for that, I urgently ask you to let me know as the first. 😀
Until than it does nothing for your reputation as an engineer to repeat like a broken record, that you know of a problem which you can't properly describe and which can't be solved in the real world.
from my understanding all your "CMP" effects are simply consequencies of the finite speed of sound (in air or any other concerning material). Absolutely nothing new with that. 🙄
If you feel the need to do something about "CMP", you probably have to raise the speed of sound beyond our limit of perception. When you have found a solution for that, I urgently ask you to let me know as the first. 😀
Until than it does nothing for your reputation as an engineer to repeat like a broken record, that you know of a problem which you can't properly describe and which can't be solved in the real world.
Until than it does nothing for your reputation as an engineer to repeat like a broken record, that you know of a problem which you can't properly describe and which can't be solved in the real world.
Possibly to raise an issue is just as interesting and creative than to solve it?
Ever heard of "the answer lies in the question" ?
Besides that - slightly OT philosophic platitudes 😉 - I do not agree that the core mechanisms of CMP behaviour - and impacts thereof - aren't already "described properly"
Regarding "solving the problem" - which seems to be everyones target instead of "understanding a problem" - my suggestion was and is :
expand into "time domain thinking" > all (your) problems solved !
Michael
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Can you lead me to any question of yours regarding "CMP" that would tangent loudspeaker DIY? Or could you reformulate it in a way that it can be understood as an issue in the practical world?
If next to nobody is reacting (as is obviously the case) either your theory or its relevance have not been properly understood. That's equivalent to "have not been properly described ".
Wouldn't it be your first duty to connect your three letters with any problem of relevance? I'm not asking you to solve my problems. It would be great if you just could explain to me, what CMP problem I haven't mentally covered yet (which is not the same as "solved").
Rudolf
Its called "utilitarianism" - again, a pretty limited concept / point of view with a pronounced egoistic / conservative component.
I suggest you to meditate on that complex too
😀
That definitely would avoid *all* malady – but what would it be any different from a single driver ?? - double mass, attach a second VC and you are there.
Real world isobaric is quite a different animal though...
Thats what you can read in my paper in case you haven't got the point:
in theory *you can* correct for CMP behaviour
in practice correction is limited for CMP systems (beyond the limits of correcting pure min phase system)
Radial modes - being CMP related - are no exception. The limitations I pointed out are of brick wall type.
Not sure what you try to tell me with this (if its aimed to me at all)
CMP is two MP systems overlaid at a certain delay. The outcome is something which has some specific characteristics not found in MP systems.
1.) the concept of FR is void – as outlined – FR concept does not allow for non- continuous spectral behaviour along the time line
2.) correction of CMP systems faces additional limits not found with MP systems – making advanced EQ'ing not obsolete in practical terms – but simply destroys the dream of „anything“ can be EQ'ed now
3.) there is CMP framing / CMP distortion - a unique behaviour to CMP systems – to my knowledge not any tackled by anyone yet
Michael
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Hi Rudolf
Some answers to your points you may already find here:
http://www.diyaudio.com/forums/multi-way/178350-zdl-22.html#post2483520
possibly some additional point I brought up regarding the isobaric discussion – which are *missed* by John's otherwise excellent page – may give you (partly) an answer ?
Have a look here:
http://www.diyaudio.com/forums/multi-way/178350-zdl-22.html#post2482498
The conclusion in your last sentence I dare to question.
😀
*If* my statement that FR concept becomes void in the presence of CMP you do not consider to be „of any relevance“ - I certainly will be unable to tell you what you „mentally haven't covered yet“
🙂
Michael
Some answers to your points you may already find here:
http://www.diyaudio.com/forums/multi-way/178350-zdl-22.html#post2483520
possibly some additional point I brought up regarding the isobaric discussion – which are *missed* by John's otherwise excellent page – may give you (partly) an answer ?
Have a look here:
http://www.diyaudio.com/forums/multi-way/178350-zdl-22.html#post2482498
The conclusion in your last sentence I dare to question.
😀
*If* my statement that FR concept becomes void in the presence of CMP you do not consider to be „of any relevance“ - I certainly will be unable to tell you what you „mentally haven't covered yet“
🙂
Michael
"CMP framing“ – what the ** you mean ?
I've just read the entire thread, and I have no idea. If you want to start a new thread, you should at least define your terms in the first post.
I've just read the entire thread, and I have no idea. If you want to start a new thread, you should at least define your terms in the first post.
Sorry for that.
This thread is already dedicated to any discussion regarding CMP - there's no need to open a new one (at least at the time being 😀).
The summary to CMP concept can be found here:
Audio and Loudspeaker Design Guide Lines
and here:
http://www.kinotechnik.edis.at/page...ine/CMP_Behaviour–Bridging_Points_of_View.pdf
didn't want to copy all that in here...
Michael
This thread is already dedicated to any discussion regarding CMP - there's no need to open a new one (at least at the time being 😀).
The summary to CMP concept can be found here:
Audio and Loudspeaker Design Guide Lines
and here:
http://www.kinotechnik.edis.at/page...ine/CMP_Behaviour–Bridging_Points_of_View.pdf
didn't want to copy all that in here...
Michael
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jamikl, I suggest that the argumentative issues be separated into categories. Ones that action is taken to mechanize, and ones that are just there for the argument. Some ideas are just not mature enough to form action on, normally 80~90% of these die eventually. Cable threads die because nobody does any true project on them. I joined this thread because this thread addressed some issues I was pondering on, and I wanted to keep track of how things went. Since making speakers disappear seems to involve many issues, I do not believe I've seen any combined studies that address enough of these. I have not studied the diffraction related issues too deeply until recently I started studying horns and wave guides; nor have I studied too deeply the directivity of direct radiating drivers. So the latest measurements I have posted was a bit surprising to me.
Joachim has the pressure with a bunch of us monitoring this thread. Additionally, his data will also be compared against other data that may be posted. Hope it does not end up like the Ariel thread.
Joachim has the pressure with a bunch of us monitoring this thread. Additionally, his data will also be compared against other data that may be posted. Hope it does not end up like the Ariel thread.
Right, a quick glance through that first link, and it seems that just mounting speakers in-wall would be a much easier option rather than all that tedious mucking around... 😉
It's the same old argument. You choose to ignore the qualification that FR is a steady state concept; that when you speak of the time line you are looking at transient behavior; that, like any other MP system, EQ of a MP system generated by the summation of multiple sources with delays suffers the same limitations as that of a single source MP response: EQ is effective only over the frequency ranges with the response is CD. Which implies that EQ is effective over the frequency range where the wave length is much longer than the delay equivalent distance. As we have discussed before, that is why dipole sources are effective only below the dipole peak.
mige0,
I glanced through your hompage CMP discussion. Is CMP anything other than envelope distortion caused by systems with non-minimum phase or secondary sources (diffraction) ? Is this simply a re-wording of the 'phase is important' arguments seen elsewhere in audio discussions?
I glanced through your hompage CMP discussion. Is CMP anything other than envelope distortion caused by systems with non-minimum phase or secondary sources (diffraction) ? Is this simply a re-wording of the 'phase is important' arguments seen elsewhere in audio discussions?
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