Good night Mr Shin,
It was a real pleasure to discuss with you, really.
I guess both camps are parltly right and parly wrong. Just my camp is a bit righter
But don't forget that this thread asked about accuton drivers experiences. Thus please purchase these drivers and let me know how much accurater these speakers are vs your floppy AT set-up.
It was a real pleasure to discuss with you, really.
I guess both camps are parltly right and parly wrong. Just my camp is a bit righter
But don't forget that this thread asked about accuton drivers experiences. Thus please purchase these drivers and let me know how much accurater these speakers are vs your floppy AT set-up.
crazyhub said:Good night Mr Shin,
It was a real pleasure to discuss with you, really.
I guess both camps are parltly right and parly wrong. Just my camp is a bit righter
Camp. I love that word, reminds me of Graham Norton
Thus please purchase these drivers and let me know how much accurater these speakers are vs your floppy AT set-up.
I just did and the experience changed my life. Unfortunately because I went all Van Gogh, I don't hear so good now.
Ramble on.
I make no claims as to this being technically gospel, more it is just my understanding gained from interpreting (maybe misinterpreting) others over the years. So if anyone sees any errors and wishes to further my knowledge, as well as hinder the pollution of others minds due to false information, please, be my guest.
The way I tend to view resonance in hard cones is a shift in efficiency.
At resonance, the cone is now excited far more because of the added 'bell-like' excitation.
Take a well damped poly cone, it 'rings' just the same as a metal cone, but to a much lower degree. You are putting energy into the cone and it alters it in one way or another. Cones on the whole are not reactive to most frequencies so the energy put in, is changed in only a minor way.
If we take the SEAS or Accutons for example, they are absolutely rigid throughout a certain frequency range, theoretically offering a performance that wont change or alter the energy, given to the cone by the motor. Floppy cones are much the same as this, for a given frequency range. Where the SEAS/Accuton differ is that they supposedly offer complete pistonic, or this accuracy of energy transfer, up into a region where the driver will be crossed over.
This in itself would be commendable if it wasn't for the effects of resonance later on, or other effects present in the cone.
The resonance peaks associated with stiff cones, almost always create problems with distortion further down, that often reach into the passband of said driver. These are harmonics within the bell like structure of the cone and nothing can be done about them. If the resonance occurs at 8000hz, if you apply energy to the cone at exactly 8000hz, this energy will synergise directly with the cones natural bell frequency and they will add constructively, hence the peak. If you apply the sound at 7900hz, providing the bell resonance is extremely high Q, it will have no profound effect, as the rate at which the cone wishes to be excited has not been met, and the change of rate of energy resists the motion of the cones natural resonance, such that the resonance isn't allowed to occur. If however you now apply a frequency of 4000hz to the cone, its at exactly a half multiple of the resonance. Although the energy presented will resist the resonance to a degree, it is also going to continue exciting the resonance twice every cycle, thus making the cone ring a little. You can't do anything about this, as its intrinsic to the cone itself, a mechanical property just like Shin said earlier on.
If the other distortions were not there, then it wouldn't be anywhere near as much of a hassle. Electrically 'removing' the notch by reducing the amount of energy given to the cone, works at controlling that one specific resonance, but it cannot compensate for the harmonics lower down. Many people have commented saying that you can predict the CSD plot from a very accurate frequency response plot. If the resonance peak is notched out, then the ridge in the CSD will disappear too. This is what I was meaning when I said efficiency. The cone rings, true, but its just a change in efficiency. You give the cone 1 watt of energy and it turns it into sound energy at say 20% efficiency. Of course the decay time on a CSD is going to be pronounced here, the rest of the loudspeaker is working at 0.15% efficiency, there is simply a lot more energy present at resonance, its naturally going to take longer to decay. Notch this out, so the energy given to the cone is vastly reduced, and the decay time follows suit.
Soft cones usually have well controlled breakups and resonances such that 'large' issues like this don't occur. However you could say they are in a state of constant break up/energy change throughout some part of the pass band. But is this really a huge issue? The cone by nature has high internal damping, so will resist energy storage and isn't stiff, so instead of ringing at one specific frequency it rings at hundreds, but due to this nature, none of them will really develop. You have a flat frequency response, without major breakup issues, but at the cost of tiny resonances.
The 'truth' of the signal, one could say, is preserved more with the stiff cone, providing the entire system takes into consideration their inherent limitations.
There could also be sound propagation issues though the cone itself, edge resonances do occur and these could pass back down though the cone structure, back towards the voice coil. Metal is naturally very good at sound transmission, soft cones are not so much.
Ramble off.
Apologies for a semi hijack.
I make no claims as to this being technically gospel, more it is just my understanding gained from interpreting (maybe misinterpreting
) others over the years. So if anyone sees any errors and wishes to further my knowledge, as well as hinder the pollution of others minds due to false information, please, be my guest. The way I tend to view resonance in hard cones is a shift in efficiency.
At resonance, the cone is now excited far more because of the added 'bell-like' excitation.
Take a well damped poly cone, it 'rings' just the same as a metal cone, but to a much lower degree. You are putting energy into the cone and it alters it in one way or another. Cones on the whole are not reactive to most frequencies so the energy put in, is changed in only a minor way.
If we take the SEAS or Accutons for example, they are absolutely rigid throughout a certain frequency range, theoretically offering a performance that wont change or alter the energy, given to the cone by the motor. Floppy cones are much the same as this, for a given frequency range. Where the SEAS/Accuton differ is that they supposedly offer complete pistonic, or this accuracy of energy transfer, up into a region where the driver will be crossed over.
This in itself would be commendable if it wasn't for the effects of resonance later on, or other effects present in the cone.
The resonance peaks associated with stiff cones, almost always create problems with distortion further down, that often reach into the passband of said driver. These are harmonics within the bell like structure of the cone and nothing can be done about them. If the resonance occurs at 8000hz, if you apply energy to the cone at exactly 8000hz, this energy will synergise directly with the cones natural bell frequency and they will add constructively, hence the peak. If you apply the sound at 7900hz, providing the bell resonance is extremely high Q, it will have no profound effect, as the rate at which the cone wishes to be excited has not been met, and the change of rate of energy resists the motion of the cones natural resonance, such that the resonance isn't allowed to occur. If however you now apply a frequency of 4000hz to the cone, its at exactly a half multiple of the resonance. Although the energy presented will resist the resonance to a degree, it is also going to continue exciting the resonance twice every cycle, thus making the cone ring a little. You can't do anything about this, as its intrinsic to the cone itself, a mechanical property just like Shin said earlier on.
If the other distortions were not there, then it wouldn't be anywhere near as much of a hassle. Electrically 'removing' the notch by reducing the amount of energy given to the cone, works at controlling that one specific resonance, but it cannot compensate for the harmonics lower down. Many people have commented saying that you can predict the CSD plot from a very accurate frequency response plot. If the resonance peak is notched out, then the ridge in the CSD will disappear too. This is what I was meaning when I said efficiency. The cone rings, true, but its just a change in efficiency. You give the cone 1 watt of energy and it turns it into sound energy at say 20% efficiency. Of course the decay time on a CSD is going to be pronounced here, the rest of the loudspeaker is working at 0.15% efficiency, there is simply a lot more energy present at resonance, its naturally going to take longer to decay. Notch this out, so the energy given to the cone is vastly reduced, and the decay time follows suit.
Soft cones usually have well controlled breakups and resonances such that 'large' issues like this don't occur. However you could say they are in a state of constant break up/energy change throughout some part of the pass band. But is this really a huge issue? The cone by nature has high internal damping, so will resist energy storage and isn't stiff, so instead of ringing at one specific frequency it rings at hundreds, but due to this nature, none of them will really develop. You have a flat frequency response, without major breakup issues, but at the cost of tiny resonances.
The 'truth' of the signal, one could say, is preserved more with the stiff cone, providing the entire system takes into consideration their inherent limitations.
There could also be sound propagation issues though the cone itself, edge resonances do occur and these could pass back down though the cone structure, back towards the voice coil. Metal is naturally very good at sound transmission, soft cones are not so much.
Ramble off.
Apologies for a semi hijack.
You often see cheap paper coned "ring"/break up almost as much as metal coned driver ... it seems that cone breakup is just as much design dependant as related to the material used
But its true that plastic coned drivers mostly measures good, but that doesnt mean they sound good
The quality of the AT drivers comes from the advanced "motor" design, and most certainly not from the cones ... I am pretty sure that with better cones they would wipe away all competition ... and the same could be said about Thiel/Accuton ... inverted cones, ouch
But its true that plastic coned drivers mostly measures good, but that doesnt mean they sound good
The quality of the AT drivers comes from the advanced "motor" design, and most certainly not from the cones ... I am pretty sure that with better cones they would wipe away all competition ... and the same could be said about Thiel/Accuton ... inverted cones, ouch
tinitus said:
I don't think poly was a cop-out but rather a genuine belief that it worked best for that design.
Audiotechnology has access to some nice tools and could have chosen from a multitude of cone materials, indeed this is an option for OEM's and private buyers with deep pockets, so its somewhat telling where their philosophy on the least compromised cone material lies when they went with mineral filled poly. Also consider the products they sell are the brain child of two of the 'greats' in transducer design, Edvind and Per Skanning, then obviously some level of thought and experience went into such decisions.
I think you're generalizing way past the data points. IMHO, the AT DO wipe away all competition. I've not heard the latest SS revelators, nor all the metal cone units, but so far the AT is the best. It does require very very good xo components to hear it at its best; but that's true of any driver in its class.tinitus said:
Incidentally my CSD/waterfall plots (MLSSA) do show that a simple peak CAN be notched successfully, so long as it's a simple peak. Some other issues are more complex of course, and would need more than a simple LCR notch.
Back to topic .... I have a friend who just finished a big design with Thiel .... 4x8", 2xmidrange and a Raven pr side .... low xo point around 650hz
He has worked on and off with Thiel drivers since they were avaiable, and never really liked them, but couldnt let them go either
He is very pleased with the result, but it was hard work to make it work ... only complain is lack of deep bass(its a closed design)
BTW ... he reckons it would have been even better with a Thiel tweeter, making a lower xo point possible
Using a sub I suppose you will use a closed box ?
He has worked on and off with Thiel drivers since they were avaiable, and never really liked them, but couldnt let them go either
He is very pleased with the result, but it was hard work to make it work ... only complain is lack of deep bass(its a closed design)
BTW ... he reckons it would have been even better with a Thiel tweeter, making a lower xo point possible
Using a sub I suppose you will use a closed box ?
tinitus said:I am pleased to hear that
I suppose that you know that Edwin Skaaning was one of the founders of Dynaudio, hence the poly cones
Along with Scanspeak and Vifa, both of whom made none poly cones. I think if you look at his previous designs and the time line of them they were quite diverse and later focused in on poly which suggests to me that he found a preference and one he believes was right.
Here's Per's thoughts:
There are always advantages and disadvantages when choosing a material for a product. In the world of transferring electrical signal into acoustic signal one must choose carefully. All materials have their own sound. Some at high frequencies and some at lower, some with a high Q breakup and other with lower. Polypropylene is the material we find with the most neutral sound, among the materials known in the business. Paper cones, liked by many serious audiophiles, have a “crispy” sound with a lot of “edge”. But this “crispy” sound is really the sound of paper adding to the sound. All materials add to the sound. One of the worst is a magnesium cone. The break-up is very pronounced and the Q of the break-up is among the highest. The faults can naturally be annulled using notch filters, but these have to be with an equal high Q and therefore far from ideal. P/P adds little to the sound and with a low Q and therefore sound natural. Some companies add a coating to paper cones, which helps damping of the high-Q break-ups and approaches the qualities of the P/P cone. Why not use a P/P cone then? Building and establishing the cone geometry and making a moving system with a good balance takes time. In house we have all the machinery for producing the tools for P/P cones. A nice tool for production costs around 7000 to 10000 US$. A paper cone tool costs almost 10 times the amount. If you do not hit the right geometry within the first couple of times, it will very fast become a costly affair. The P/P tools can be adjusted into hitting the right geometry and you therefore have much more attempts with a relative low cost. It is quite seldom one comes across a driver with paper cone and a nice useable frequency response. We believe P/P cones, all things taken into consideration, are the best.
A soft flexing cone as those made of PP will have more distortion than a rigid cone such a ceramic or magnesium. The bending and flexing of the PP cone will suffer from non-linear effects and also hysteresis.. a memory effect. Try go bending on a piece of plastic from a plastic jar/bottle.
The biggest issues is dispersion and the useable bandwith. If you want to build a two way speaker with high output you will have to go with a soft flexing cone in order to end up with a good match betwween bass and tweeter where they meet at the crossover region. Sure, if you can live with a big dip in the off axis upper range this is less of a problem one could argue.
A rigid cone could be a better choice for a low output speaker or you simply move to a three or four way which off course introduces new nuts to crack regarding off axis suming and phase distortion. Engineering it'scalled.
The break up peak in rigid cones is no problem IMO if the drivers are used right. A notch is good, crossing the driver low is good. Also using a low distortion motor so there are less distortion around that can excite the cone resonance is also important. Speaker drivers usually have low amounts of high order distortion so even if the amplitud of the harmonic is amplified by the 10dB or so cone break up that would mean little if the end result is low. It's not the "ringing" you hear in a rigid driver with break up, it's the peak in frequency response. Attenuate the peak and problem gone.
Many manufacturers keep on going with the stuff their used with.. habits are hard to break for human beings. The equipment needed for manufatcuring ceramic and diamond drivers are not cheap and that is one reason few does it.
Me? Still rigid drivers of course.
Oh, a common belief is that the more rigid drivers are truly pistonic until they hit the break up. Is it really so? I have no laser inferometry thingy around but I'd put a Swedish krona or two on the idea that the cone start flexing waaay below the major resonance. Not much of a problem if the flexing is small (which it is with a more rigid cone) since it doesn't alter the output of the cone significantly. The more the cone is allowed to flex (PP) and the more non linear it is the more the output is altered iow. more distortion is produced.
/Peter
The biggest issues is dispersion and the useable bandwith. If you want to build a two way speaker with high output you will have to go with a soft flexing cone in order to end up with a good match betwween bass and tweeter where they meet at the crossover region. Sure, if you can live with a big dip in the off axis upper range this is less of a problem one could argue.
A rigid cone could be a better choice for a low output speaker or you simply move to a three or four way which off course introduces new nuts to crack regarding off axis suming and phase distortion. Engineering it'scalled.
The break up peak in rigid cones is no problem IMO if the drivers are used right. A notch is good, crossing the driver low is good. Also using a low distortion motor so there are less distortion around that can excite the cone resonance is also important. Speaker drivers usually have low amounts of high order distortion so even if the amplitud of the harmonic is amplified by the 10dB or so cone break up that would mean little if the end result is low. It's not the "ringing" you hear in a rigid driver with break up, it's the peak in frequency response. Attenuate the peak and problem gone.
Many manufacturers keep on going with the stuff their used with.. habits are hard to break for human beings. The equipment needed for manufatcuring ceramic and diamond drivers are not cheap and that is one reason few does it.
Me? Still rigid drivers of course.
Oh, a common belief is that the more rigid drivers are truly pistonic until they hit the break up. Is it really so? I have no laser inferometry thingy around but I'd put a Swedish krona or two on the idea that the cone start flexing waaay below the major resonance.
Not much of a problem if the flexing is small (which it is with a more rigid cone) since it doesn't alter the output of the cone significantly. The more the cone is allowed to flex (PP) and the more non linear it is the more the output is altered iow. more distortion is produced. /Peter
Pan said:
Come on, get down on the manufacturers all you like but with verbage like that your infering that people, as much as the manufacturers, who don't go with rigid cones aren't moving with the times and "keep going with stuff their used to". Um, maybe thats because they sound better? No ignore that its a crazy idea. Progress always comes from whatever the manufacturers say is more technologically advanced.
You own rigid cones, I own floppy cones. Its clear that there's bias here. I can say I've sampled both and formed a preference regardless of what is and what isn't considered current.
Re: Re: Ramblings
It is exactly the other way around, soft cones do "spread" resonances due to break-up effects. The reason for break-up is the transition of the cone material to the dampening ring of the speaker. As a hard cone is rigid, the breakup will show itself more prominent at one frequency. For soft cones, like paper or poly, the cone itself bends with the reflections on the edge of the dampening ring, and hence spreads over a wider frequency range. The effect instead of a sharp peak, is a more distributed peak, more intermodulation products due to cone standing waves, and harmonic distortion.
You can only attenuate the effect with notches, which just like soft cones don't "solve" the problem, but mask it to manageable proportions.
The best way (and common practice of experienced designers) is to stay away from the frequency range where breakup takes place. In many cases, cone breakup also reveals itself as harmonic distortion, e.g. a 3kHz cone break-up is exited by a 1kHz signal. This means that in that case, you have to stay away from that region of a unit as well. If you measure and understand the effects, cone breakup effects can be limited to inaudible proportions in practical cases.
In case of a Thiel/Accuton C2 220, there is a significant cone-breakup peak at 3.4kHz, which can be attenuated by a notch. In case of a 2nd order crossover with about 30dB attenuation at 3.4kHz, the notch is audible for selected material (e.g. choir music) when applied to the woofer in isolation. When a midrange/tweeter pair is added to the woofer, the notch becomes inaudible. Hence, 30dB attenuation is sufficient, and for the die-hards you can even apply a notch if that would comfort you.
Just like about any parameter in a unit...
The subtle quote "when used correctly" holds for any speaker, and is the curlpit of your remark.
The analogy is wrong, because as opposed to room reflections of which you have many, the source of breakup is at one place (not completely due to the size of the unit, but that would bring us to the discussion of every source that is not a point-source). Nevertheless, your argument to prevent the problem at the source is completely right, which for breakups mean... just prevent them by.... staying away from them by... A.) Pretend paper/poly cones are the solution. B.) Apply proper filtering that doesn't exite breakup effects. B works for any case!
The faith in paper/poly is similar. It's a means, not a goal, and with proper engineering, one can make them sound (almost) identical. I've heard experiments where a lousy speaker with a long plastic tube glued in front, sounded like a good and nice speaker with the right type of signal processing applied.
Exactly!
It depends on the source of the resonance/brakup, and whether it is a linear effect. In cone breakups and reflections, the effect is not linear, and hence can't be eliminated by a passive conjugate network. In case of MFB-type of regulation loops, one can remove non-linear distortions and cone breakups. I can remember an experiment where a big paper Peerless woofer in a cabinet. When tapping it with a finger, one could hear a "bwooop bwooop bwooop" type of sound. When you enabled the MFB feedback loop, it sounded as a "piece of wood" sounding more like "t t t".
If resonances, breakups and cone characteristics are your thing, then MFB-like techniques are needed to remove them from your system, whether it is ceramic or paper.
If not properly filtered, they do sound like that. The C2 220 woofer needs 2nd order filtering with a crossover at < 200Hz, otherwise it sound "compressed" and "cannned". The C2 12 tweeter sound "harsh" and "condenses/shuts-in" the sound when used below 2-3kHz. Not many people design with these units that way, revealing exactly what you say.
In my case, I do use Mahler, Shostakovich, Stravinsky and Mozart's Requiem to show these units can have extreme dynamics AND transparancy (that combination is hard to find with other type of units, and probably the engineering challenge in that case), and sound "musical". Most people listening to my speakers say "they don't sound like Accuton-based speakers, but I do hear the speed of the Accutom units".
I'm quite impressed with the Seas Magnesium 15cm unit for the same reasons.
Which is true for many designs based on Accutons, I fully agree. Most designers "solve" the shut-in sound by increasing treble, and make the speaker "crisp". But overall, they sound unacceptable.
I'm biased towards good sounding speakers, and I don't care what they use. My preference for speakers differs with room and music type.
I feel that many paper-coned designs have much intermodulation distortion, and they only sound nice with combo-music (vocal jazz, folk, classical chamber music), but severly start to choke with choir music. It also hints at typical use of these cone types, 2-way systems where the paper-based units are used up-to their breakup.
A significant part of the sound of a speaker unit is determined by the dampening mechanism as well.
Marc
ShinOBIWAN said:Yeah a driver just doesn't sound right unless its rigid cone is spraying resonance induced harmonics all over the frequency spectrum.
It is exactly the other way around, soft cones do "spread" resonances due to break-up effects. The reason for break-up is the transition of the cone material to the dampening ring of the speaker. As a hard cone is rigid, the breakup will show itself more prominent at one frequency. For soft cones, like paper or poly, the cone itself bends with the reflections on the edge of the dampening ring, and hence spreads over a wider frequency range. The effect instead of a sharp peak, is a more distributed peak, more intermodulation products due to cone standing waves, and harmonic distortion.
ShinOBIWAN said:
You can only attenuate the effect with notches, which just like soft cones don't "solve" the problem, but mask it to manageable proportions.
The best way (and common practice of experienced designers) is to stay away from the frequency range where breakup takes place. In many cases, cone breakup also reveals itself as harmonic distortion, e.g. a 3kHz cone break-up is exited by a 1kHz signal. This means that in that case, you have to stay away from that region of a unit as well. If you measure and understand the effects, cone breakup effects can be limited to inaudible proportions in practical cases.
In case of a Thiel/Accuton C2 220, there is a significant cone-breakup peak at 3.4kHz, which can be attenuated by a notch. In case of a 2nd order crossover with about 30dB attenuation at 3.4kHz, the notch is audible for selected material (e.g. choir music) when applied to the woofer in isolation. When a midrange/tweeter pair is added to the woofer, the notch becomes inaudible. Hence, 30dB attenuation is sufficient, and for the die-hards you can even apply a notch if that would comfort you.
ShinOBIWAN said:
Just like about any parameter in a unit...
ShinOBIWAN said:
The subtle quote "when used correctly" holds for any speaker, and is the curlpit of your remark.
ShinOBIWAN said:
The analogy is wrong, because as opposed to room reflections of which you have many, the source of breakup is at one place (not completely due to the size of the unit, but that would bring us to the discussion of every source that is not a point-source). Nevertheless, your argument to prevent the problem at the source is completely right, which for breakups mean... just prevent them by.... staying away from them by... A.) Pretend paper/poly cones are the solution. B.) Apply proper filtering that doesn't exite breakup effects. B works for any case!
ShinOBIWAN said:
The faith in paper/poly is similar. It's a means, not a goal, and with proper engineering, one can make them sound (almost) identical. I've heard experiments where a lousy speaker with a long plastic tube glued in front, sounded like a good and nice speaker with the right type of signal processing applied.
ShinOBIWAN [/i]IMO Accuton are the worst kind of high end driver for creating music.[/QUOTE] Based on your opinion and interpretation said:
Exactly!
Curmudgeon said:
It depends on the source of the resonance/brakup, and whether it is a linear effect. In cone breakups and reflections, the effect is not linear, and hence can't be eliminated by a passive conjugate network. In case of MFB-type of regulation loops, one can remove non-linear distortions and cone breakups. I can remember an experiment where a big paper Peerless woofer in a cabinet. When tapping it with a finger, one could hear a "bwooop bwooop bwooop" type of sound. When you enabled the MFB feedback loop, it sounded as a "piece of wood" sounding more like "t t t".
If resonances, breakups and cone characteristics are your thing, then MFB-like techniques are needed to remove them from your system, whether it is ceramic or paper.
Curmudgeon said:
If not properly filtered, they do sound like that. The C2 220 woofer needs 2nd order filtering with a crossover at < 200Hz, otherwise it sound "compressed" and "cannned". The C2 12 tweeter sound "harsh" and "condenses/shuts-in" the sound when used below 2-3kHz. Not many people design with these units that way, revealing exactly what you say.
In my case, I do use Mahler, Shostakovich, Stravinsky and Mozart's Requiem to show these units can have extreme dynamics AND transparancy (that combination is hard to find with other type of units, and probably the engineering challenge in that case), and sound "musical". Most people listening to my speakers say "they don't sound like Accuton-based speakers, but I do hear the speed of the Accutom units".
Curmudgeon said:
I'm quite impressed with the Seas Magnesium 15cm unit for the same reasons.
ShinOBIWAN said:
Which is true for many designs based on Accutons, I fully agree. Most designers "solve" the shut-in sound by increasing treble, and make the speaker "crisp". But overall, they sound unacceptable.
ShinOBIWAN said:
I'm biased towards good sounding speakers, and I don't care what they use. My preference for speakers differs with room and music type.
I feel that many paper-coned designs have much intermodulation distortion, and they only sound nice with combo-music (vocal jazz, folk, classical chamber music), but severly start to choke with choir music. It also hints at typical use of these cone types, 2-way systems where the paper-based units are used up-to their breakup.
ShinOBIWAN said:
A significant part of the sound of a speaker unit is determined by the dampening mechanism as well.
Marc
5th element said:
Nope, it reveals just differently. Resonances are determined by the ratio between reactive and resisitve components, where the spider plays a dominant role in what degree something "rings".
5th element said:
If they would not be reactive to a frequency, they would be deadly silent!
5th element said:
If and only if the whole drive train is rigid, which it is not by definition. The linearity and rigidness of the motuin is the combination of the cone, the dampening ring, the spider, the Xmax etc.
And here is a point where I speculate myself. My gut feel is that the rigidness of the cone helps in the uniform spreading of the sound, because the displacement of the cone is rather constant over a big area, and the group delay is perfectly aligned over a large area. And I think that this adds to the sense of "speed" and "transparancy". Electrostatic speakers have a similar property, because their radiating area is so much bigger than the area at the boundary of the speaker, and the uniform motion is relatively large. "Transparant", "micro-dynamics" and "speed" is the key-word when it comes to well-designed electrostatic speakers, or rigid-cone based speakers.
5th element said:
There is a big difference in resonance and breakup. Besides for low frequences (woofers), one should stay away from resonances as well. Speaker resonances can be dampened pretty well with notches.
5th element said:
Not at all, they reveal themselves as (audible) intermodulation products.
5th element said:
When changing the prefix into "The radiation of the signal from the cone is preserved more", you have bingo!
Marc
Shinobiwan,
did you read my entire post or just selected parts of it?
There are situations where a more flexing cone is to prefer in my opinion..
I really can't see anything that is not true with what I wrote and I can not understand your reaction. Yes, I have also had all sorts of drivers and also drivers that mr Skaaning senior was involved with.
My opinion is also that the best soft coned drivers are those that comes from Skaaning and Ino Audio.
For myself I prefer rigid drivers as you've noticed, especially for lows and highs. I'm slightly more open for a softer driver in the midrange due to the facts I mentioned in my post above. There's really no advantage in using flexing cones for lows and highs where dispersion is less of a problem and the break up is extremly well surpressed and/or out of the audible range.
I'm considering a Skaaning midrange in a four way prototype btw!
/Peter
did you read my entire post or just selected parts of it?
There are situations where a more flexing cone is to prefer in my opinion..
I really can't see anything that is not true with what I wrote and I can not understand your reaction. Yes, I have also had all sorts of drivers and also drivers that mr Skaaning senior was involved with.
My opinion is also that the best soft coned drivers are those that comes from Skaaning and Ino Audio.
For myself I prefer rigid drivers as you've noticed, especially for lows and highs. I'm slightly more open for a softer driver in the midrange due to the facts I mentioned in my post above. There's really no advantage in using flexing cones for lows and highs where dispersion is less of a problem and the break up is extremly well surpressed and/or out of the audible range.
I'm considering a Skaaning midrange in a four way prototype btw!
/Peter
Well, you are really good at complicating things
Every ideal driver is pistonic within its range/passband which is dependent on its size
Which also means it will have very limited passband
To make a certain size of driver useable above its ideal passband it will have to flex, otherwise it will go in breakup mode
A good widerange has a controlled concentric flex which sort of makes the driver smaller
A nice curved shape will help this further
Ribbed cones works in a similar way, or ScSp "slit-cones"
I think that to use true pistonic drivers the result will be at least a 4way design to get best result
Every ideal driver is pistonic within its range/passband which is dependent on its size
Which also means it will have very limited passband
To make a certain size of driver useable above its ideal passband it will have to flex, otherwise it will go in breakup mode
A good widerange has a controlled concentric flex which sort of makes the driver smaller
A nice curved shape will help this further
Ribbed cones works in a similar way, or ScSp "slit-cones"
I think that to use true pistonic drivers the result will be at least a 4way design to get best result
Given our experience with the smallest Skaaning mid, you might want to consider a 3 way instead. After getting rid of the series capacitor, and just using the sealed mid cabinet for the low end rolloff, we wound up with xo points of 95 and 3800 Hz. I'd suggest perhaps 125 preferably, but so far we're fine, although the system is not run at terribly high volumes.Pan said:
I'm considering a Skaaning midrange in a four way prototype btw!
/Peter
Mid continuity is excellent of course, and the SS Rev 99000 is never stressed. And the Skaaning mid shows no sign of low end difficulty.
Re: Re: Re: Ramblings
Your talking about high Q resonance versus a low Q one. Just as with filtering the higher the Q the more ripple in the time domain.
A paper or poly cone doesn't have resonances all over its entire passband but has a breakup much like a stiffer cone does. The difference is that it stores less energy, has that lesser energy spread over a larger area and has less time domain ripple.
Wasn't talking about reflections per-se but room mode induced time smearing or resonance. Stick the mic at the mode, you see a FR hump, you see the extended decay on the CSD, you notch this out with EQ. Did you damp the resonance or just attenuate it? Did you fix that room issue?
This applies to the driver resonance as well.
I'll tell you something, I'll think twice about using an analogy again because it seems I'm the only one that can relate to them and rather than helping it just confuses.
The floppy cones have the better balance but aren't the solution no.
I'm a realist though, I know poly and everything else is flawed thats why I agonise over driver choices. The OP was claiming inherent colouration could be solved with a notch filter - an over simplification which I objected to.
BTW Signal processing used in such extremes does more harm than initial problem. Can I mention room correction again?
Its all my opinion of course, is that better?
<screams into a pile of acoustic foam>
What are you judging the dynamics of those Accuton against?
Have you heard the Marten Coltrane and Bird designs or the Avalon Eidolon? All these feature Accuton drivers and are the ones that I'm basing my opinion of the Accuton sound.
For perspective to see just how dynamic they are go listen to a pair of ATC's and experience the floppiest of domes producing some whip crack dynamics.
That was my point, invariably I find good sounding speakers are the ones with low Q cone breakup.
I've said the same about Accuton, they don't convince on simple music and it just gets worse as the complexity goes up. Never before have I heard the Prodigy sound so dull and lifeless.
Conclusion: Until I hear otherwise I don't think you'll ever see me say anything nice about the Accuton sound and certainly not using these drivers in any of my own designs. That my friends is a preference akin to not having broken glass rubbed in my face.
marche said:
Your talking about high Q resonance versus a low Q one. Just as with filtering the higher the Q the more ripple in the time domain.
A paper or poly cone doesn't have resonances all over its entire passband but has a breakup much like a stiffer cone does. The difference is that it stores less energy, has that lesser energy spread over a larger area and has less time domain ripple.
Wasn't talking about reflections per-se but room mode induced time smearing or resonance. Stick the mic at the mode, you see a FR hump, you see the extended decay on the CSD, you notch this out with EQ. Did you damp the resonance or just attenuate it? Did you fix that room issue?
This applies to the driver resonance as well.
I'll tell you something, I'll think twice about using an analogy again because it seems I'm the only one that can relate to them and rather than helping it just confuses.
The floppy cones have the better balance but aren't the solution no.
I'm a realist though, I know poly and everything else is flawed thats why I agonise over driver choices. The OP was claiming inherent colouration could be solved with a notch filter - an over simplification which I objected to.
BTW Signal processing used in such extremes does more harm than initial problem. Can I mention room correction again?
Its all my opinion of course, is that better?
<screams into a pile of acoustic foam>
What are you judging the dynamics of those Accuton against?
Have you heard the Marten Coltrane and Bird designs or the Avalon Eidolon? All these feature Accuton drivers and are the ones that I'm basing my opinion of the Accuton sound.
For perspective to see just how dynamic they are go listen to a pair of ATC's and experience the floppiest of domes producing some whip crack dynamics.
That was my point, invariably I find good sounding speakers are the ones with low Q cone breakup.
I've said the same about Accuton, they don't convince on simple music and it just gets worse as the complexity goes up. Never before have I heard the Prodigy sound so dull and lifeless.
Conclusion: Until I hear otherwise I don't think you'll ever see me say anything nice about the Accuton sound and certainly not using these drivers in any of my own designs. That my friends is a preference akin to not having broken glass rubbed in my face.
Pan said:Shinobiwan,
did you read my entire post or just selected parts of it?
I did Pan.
It was bizarre given that AT can use a range of cone materials on their motors depending on what you spec. I've seen paper and carbon fibre cone variations on the usual poly.
I also took it that you meant rigid cones to be superior as why else would you consider manufacturers to be slow on the up take and set in their ways if they hadn't migrated yet?
I think it's important that the damping characteristics of the cone be considered, which is one reason that I think "paper or plastic" might be simplistic anywhere but the grocery store.
I used the SS 8636 little kevlar mid in a commercial design. It was fine, very natural, musical, easy to xo. It was treated with a non-hardening damping compound; any other Kevlar unit I heard had a nasty breakup, (none were damped) and crossing those over just isn't all that much fun. Since I like the lower order multi-slope approach, an explosive HF breakup is pretty much a nonstarter for me.
And where do you put carbon-reinforced paper, like the SS woofers? (Which I like very much.) And does the old Bozak formula which was "paper", but mostly high grade rag (linen?) really qualify as paper? Or the Fostex banana "paper"? (Which I also like based on one model only.)
The nice thing about polyprope is that it is self damping, and the degree is easily modified by changing the filler.
I used the SS 8636 little kevlar mid in a commercial design. It was fine, very natural, musical, easy to xo. It was treated with a non-hardening damping compound; any other Kevlar unit I heard had a nasty breakup, (none were damped) and crossing those over just isn't all that much fun. Since I like the lower order multi-slope approach, an explosive HF breakup is pretty much a nonstarter for me.
And where do you put carbon-reinforced paper, like the SS woofers? (Which I like very much.) And does the old Bozak formula which was "paper", but mostly high grade rag (linen?) really qualify as paper? Or the Fostex banana "paper"? (Which I also like based on one model only.)
The nice thing about polyprope is that it is self damping, and the degree is easily modified by changing the filler.
Re: Re: Re: Ramblings
I've no desire to jump in on all of the subjective stuff being passed off as objective in the thread and I have my own preferences that I question when I make the effort to test a different type of driver. However, I do not agree with the statement that claims that breakup and even internal reflections are not linear. At any given signal level it is possible to correct in the analog domain and does not require DSP nor MFB. My position on this is due to my first-hand experience, it's not conjecture. I have the design and subsequent measurements to support this. It may not be practical in some cases due to complexity, but that's another issue altogether.
The complicating factor would be if the FR deviations change with signal level. In good drivers I'm not convinced that this as a significant problem for whatever material is used if the driver is used in a passband appropriate for that driver and sufficiently into the stop-band. This puts it in the area of design tradeoffs that must occur in every design.
A complicating issue for drivers with high-Q, high magnitude peaks is driver-to-driver consistency. Any driver that requires a significant trap may need tuning for each driver. This is more likely a disadvantage of hard materials since they generally exhibit these symptoms to a higher degree. On the other hand, it seems that it's easier to maintain consistency with hard materials. Then again, hard materials seem to have better FR in their passband (note the avoidance of using the confusing term linear). But the small deviations in doped paper and other not-as-stiff materials may be benign.
I don't see any driver material as being best in absolute terms, each has strengths and weaknesses, but I have to say that the best systems I have heard using piston drivers have all used some form of doped paper such as those in the SS and Seas lines. I can't describe the specifics of what is responsible, but in the years that I've listened to purchased systems and built them myself, no hard coned material came close, though many were certainly good and some are getter much closer. My preference, though, is for low order (usually LR2) crossovers, so hard diaphragms usually won't work well enough.
Dave
marche said:
I've no desire to jump in on all of the subjective stuff being passed off as objective in the thread and I have my own preferences that I question when I make the effort to test a different type of driver. However, I do not agree with the statement that claims that breakup and even internal reflections are not linear. At any given signal level it is possible to correct in the analog domain and does not require DSP nor MFB. My position on this is due to my first-hand experience, it's not conjecture. I have the design and subsequent measurements to support this. It may not be practical in some cases due to complexity, but that's another issue altogether.
The complicating factor would be if the FR deviations change with signal level. In good drivers I'm not convinced that this as a significant problem for whatever material is used if the driver is used in a passband appropriate for that driver and sufficiently into the stop-band. This puts it in the area of design tradeoffs that must occur in every design.
A complicating issue for drivers with high-Q, high magnitude peaks is driver-to-driver consistency. Any driver that requires a significant trap may need tuning for each driver. This is more likely a disadvantage of hard materials since they generally exhibit these symptoms to a higher degree. On the other hand, it seems that it's easier to maintain consistency with hard materials. Then again, hard materials seem to have better FR in their passband (note the avoidance of using the confusing term linear). But the small deviations in doped paper and other not-as-stiff materials may be benign.
I don't see any driver material as being best in absolute terms, each has strengths and weaknesses, but I have to say that the best systems I have heard using piston drivers have all used some form of doped paper such as those in the SS and Seas lines. I can't describe the specifics of what is responsible, but in the years that I've listened to purchased systems and built them myself, no hard coned material came close, though many were certainly good and some are getter much closer. My preference, though, is for low order (usually LR2) crossovers, so hard diaphragms usually won't work well enough.
Dave
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