Disabled Account
Joined 2003
err...
Most products claims to have "ultimate quality" as it's goal. If you listen to the companies, they are all the best.
Engineering is about compromises and tradeoffs. You can't get the best of the best of everything.
When you use a larger magnet you reduce airflow and typically reduce bass (Qts). Using a larger voice coil (eg. 3" ala Dynaudio style) gives higher power handling but ...[fill in the blanks]
Skaaning's AT drivers apparently use "some of the best motors in the business" (LDSG). They also use polypropylene cones. The aim of this is, IMHO, to ensure a smooth rolloff outside the passband, and thus faciliating easy crossover work. This is particularly welcome by DIYers who don't have measurement equipment and must rely on textbook-formula crossovers.
Some manufacturers use metal or other stiff composite cones for a more pistonic movement in an attempt to lower linear (~energy storage) and non-linear (~harmonic) distortion. The downside with all stiff cones is that they tend to resonate at some particular band of frequencies. Hence the speaker is going to sound horrible if you use shallow slope crossovers without traps (notch filters) for the ringing.
Better drivers have these cone breakups a little further out of their passband, but you still have to deal with it by a properly designed crossover. Throw away all those textbook crossover formulas and you better invest in some measuring equipment and software. Otherwise you'll never get it right.
I don't agree with Per Skaaning's argument regarding evaluation of a driver without a crossover. That's fine, if that driver is going to be used without a crossover. eg. full range driver, but when the system will use a crossover you need to evaluate the entire system. A crossover is not a just a filter. It tailors the frequency response and overall voicing.
IMHO the two greatest advantages of using AT drivers is that
1) you can place custom orders, even when ordering single units.
2) you can achieve good results even without a proper XO design, simply because the driver have a very flat and smooth broadband frequency response AND rolls off smoothly.
Anyway i'm going to stop now. Don't want to upset any AT users...
Most products claims to have "ultimate quality" as it's goal. If you listen to the companies, they are all the best.
Engineering is about compromises and tradeoffs. You can't get the best of the best of everything.
When you use a larger magnet you reduce airflow and typically reduce bass (Qts). Using a larger voice coil (eg. 3" ala Dynaudio style) gives higher power handling but ...[fill in the blanks]
Skaaning's AT drivers apparently use "some of the best motors in the business" (LDSG). They also use polypropylene cones. The aim of this is, IMHO, to ensure a smooth rolloff outside the passband, and thus faciliating easy crossover work. This is particularly welcome by DIYers who don't have measurement equipment and must rely on textbook-formula crossovers.
Some manufacturers use metal or other stiff composite cones for a more pistonic movement in an attempt to lower linear (~energy storage) and non-linear (~harmonic) distortion. The downside with all stiff cones is that they tend to resonate at some particular band of frequencies. Hence the speaker is going to sound horrible if you use shallow slope crossovers without traps (notch filters) for the ringing.
Better drivers have these cone breakups a little further out of their passband, but you still have to deal with it by a properly designed crossover. Throw away all those textbook crossover formulas and you better invest in some measuring equipment and software. Otherwise you'll never get it right.
I don't agree with Per Skaaning's argument regarding evaluation of a driver without a crossover. That's fine, if that driver is going to be used without a crossover. eg. full range driver, but when the system will use a crossover you need to evaluate the entire system. A crossover is not a just a filter. It tailors the frequency response and overall voicing.
IMHO the two greatest advantages of using AT drivers is that
1) you can place custom orders, even when ordering single units.
2) you can achieve good results even without a proper XO design, simply because the driver have a very flat and smooth broadband frequency response AND rolls off smoothly.
Anyway i'm going to stop now. Don't want to upset any AT users...
You can keep on, I fully agree with your assessment of the AT situation.
Engineering is all about compromise but I don't seem to think that all of the companies using advanced hard cones use a motor as good as AT's. This could come down to an issue of overall cost and sales tactics. If a company can say that they use an amazingly pistonic cone material then they can use that as there selling point. It's all about the business side of things.
I would love to use an accuton driver but do have they invested enough time into motor development? I think they are getting better but may not quite be there yet.
Why can't there be a best overall mid with a few certain variables ruled out. If you are going to go with a digital setup, which many are these days, then sensitivity is not as much of an issue. If you use a really nice 10 or 12" driver that is flat out past 500Hz then having a mid reach down to the depths is not that much of an issue. If a really nice tweet with a decent response is used then we can keep the passband of the mid in the 2-2.5K range.
With these limitations being set, why can't there be an overall winner for detail, musicality and normal spl output from about 300-2.5KHz??
Anyways.....
Engineering is all about compromise but I don't seem to think that all of the companies using advanced hard cones use a motor as good as AT's. This could come down to an issue of overall cost and sales tactics. If a company can say that they use an amazingly pistonic cone material then they can use that as there selling point. It's all about the business side of things.
I would love to use an accuton driver but do have they invested enough time into motor development? I think they are getting better but may not quite be there yet.
Why can't there be a best overall mid with a few certain variables ruled out. If you are going to go with a digital setup, which many are these days, then sensitivity is not as much of an issue. If you use a really nice 10 or 12" driver that is flat out past 500Hz then having a mid reach down to the depths is not that much of an issue. If a really nice tweet with a decent response is used then we can keep the passband of the mid in the 2-2.5K range.
With these limitations being set, why can't there be an overall winner for detail, musicality and normal spl output from about 300-2.5KHz??
Anyways.....
"If a company can say that they use an amazingly pistonic cone material then they can use that as there selling point"
Or you can simply accept that a stiff cone has lower distortion than a soft and therefore gives less coloration and higher resolution.
"With these limitations being set, why can't there be an overall winner for detail, musicality and normal spl output from about 300-2.5KHz??"
Sounds like you ask for the Accuton C90.
/Peter
Or you can simply accept that a stiff cone has lower distortion than a soft and therefore gives less coloration and higher resolution.
"With these limitations being set, why can't there be an overall winner for detail, musicality and normal spl output from about 300-2.5KHz??"
Sounds like you ask for the Accuton C90.
/Peter
Disabled Account
Joined 2003
Again I'm going to quote someone else...
Linkwitz investigated a handful of drivers from 5" to 8" when designing the Orion.
In his midrange distortion test he notes:
"Note 2: A low distortion driver for the 500 Hz to 3 kHz range is hard to find..."
Just some food for thought. I find his website so educational and interesting...
Its interesting to see that the accuton performs so badly. According to linkwitz this could be because of the motor etc. It would be nice if AT made a ceramic/metal/stiff coned driver and then looked at how it performs.
But I do think that SEAS are going in the correct direction using Neo magnets in their hexadym system, maintaining a high BL whilst getting as close to zero backwaver reflection as possible.
The one thing I dont like about the AT driver is the huge magnet behind the cone. Now if they we to use Neo magnets and a stiff cone I may consider them.
But I do think that SEAS are going in the correct direction using Neo magnets in their hexadym system, maintaining a high BL whilst getting as close to zero backwaver reflection as possible.
The one thing I dont like about the AT driver is the huge magnet behind the cone. Now if they we to use Neo magnets and a stiff cone I may consider them.
I completely agree with you 5th. There are some companies that are definitely going down the right road but no one seems to have brought all the best combinations together yet. Someday soon I hope.
I have always been a little weary of Accuton's factory measurements so I can't say that I really trust the new info that is floating around. I would love to have someone get there hands on the new c90 and do some actual tests.
goskers
I have always been a little weary of Accuton's factory measurements so I can't say that I really trust the new info that is floating around. I would love to have someone get there hands on the new c90 and do some actual tests.
goskers
Disabled Account
Joined 2003
Again I think it is all about compromise. i do not believe there is such a thing as 'all the best combinations'
If I look into the release lineup of the experienced manfacturers they basically have gone through many different materials and various magnet designs. In the current Seas standard-line they have paper, polypropylene, aluminium and a single glass fibre cone. They've also been through TPX and various other composites.
The Excel line, with improved magnet system uses magnesium, aluminium and polypropylene. Fibreglass used to feature prominently in the Excel line, concurrently with magnesium. I can still browse the Seas' archive section, and compare fibreglass and magnesium versions of the same driver. I find it interesting reading but your mileage may vary.
Of the current models, there are plenty of polypropylene drivers in the standard line, but only a single one in Excel lineup- the 15cm midrange M15CH001.
When I look at it's published data to compare to other 15cm Excel drivers, it seems to have much smoother frequency response and nice rolloff (easy 1st order crossover no problems) compared to the magnesium driver with normal (W15CY001) and neo (W15CH001) magnet systems, in fact ALL other Excel drivers.
But it's bit higher in distortion all throughout the passband. In fact the only time it can match/beat the others in distortion is past 3Khz...
On the other hand the W15CY and W15CH have lower distortion below 2Khz. Above this the harmonic distortion jumps because these harmonics fall into the resonance modes.
So ideally they're best used under 2Khz. And even if I was going to crossover below 2Khz I'd need to be able to get the notch filter exactly right to get rid of those primary resonance peaks.
(see Fig 3 http://www.audioxpress.com/reviews/media/403colin-dapp2204.pdf ) for an example of a mal-aligned notch filter. Fig. 5B, 5C and the Critique box (listening impressions) show consequences of such a error. My intention is not the criticise the design but to give an example of the what can happen when your notch filter misses the resonance peak.
Interestingly, AT publish only their exemplary FR measurements.
I'd be interested in seeing some distortion measurements.
More food for thought:
http://206.13.113.199/ncdiyaudio/mark/Midrange test group/midrange_test_data.htm
About the Excel 15CY/CH, I was a little dissapointed by how the neo-driver looks at Seas own measurements. I had hoped for as good as (or better) cone behaviour as the old one and lower HD. Judging by numbers, the new one seems like no improvement over the "old" one. I am about to test them both soon though.
I am more impressed by the new Accuton C90. They have made a lower distortion higher sensitivity motor with a better behaved cone compared with the older 7"ers. Exactly the improvements I was thinking about a couple of years ago when using C92.
If judging drivers by HD as measured by manufacturers, the Eton 5" and new 7" looks interesting as well.
/Peter
I am more impressed by the new Accuton C90. They have made a lower distortion higher sensitivity motor with a better behaved cone compared with the older 7"ers. Exactly the improvements I was thinking about a couple of years ago when using C92.
If judging drivers by HD as measured by manufacturers, the Eton 5" and new 7" looks interesting as well.
/Peter
Disabled Account
Joined 2003
Pan said:
The old eton 7" is a very good driver in a 2 or 2.5 way, I'm working on a 2.5 way design in combination with the er4.
Measurements of HobbyHifi on the new 7" didn't impress me. I think it's a way to cut costs, because the old one featured a larger magnet, larger xmax and a heatpipe. So I chose the old one.
Disabled Account
Joined 2003
"I will be mating this mid to a 5" true ribbon so speed and accuracy will come into play here. This will be in a sealed enclosure so I am contemplating the 15x series vs the 18 which would be much better in a dipole config."
you will want a VERY low mass diaphram in conjunction with the ribbon. drivers like this usually work better, (MUCH better), with amplifiers that have lower dampening factors (see also "current amps" posted here by Pass and co.).
additionally you'll need a driver that can be crossed-over fairly high for the ribbon.
the driver I'd suggest is this one.. (notice the mass vs. the sd):
http://www.jssystem.it/IT/Prodotti/ATD/Veravox5x.htm
Its not cheap and the freq. response isn't perfectly flat BUT it has a very low energy storage signiture because of the low mass. Hobby HiFi did a set of measurements on this driver and the CSD is VERY clean and the freq. response from 300 to 3k is reasonably flat.
you will want a VERY low mass diaphram in conjunction with the ribbon. drivers like this usually work better, (MUCH better), with amplifiers that have lower dampening factors (see also "current amps" posted here by Pass and co.).
additionally you'll need a driver that can be crossed-over fairly high for the ribbon.
the driver I'd suggest is this one.. (notice the mass vs. the sd):
http://www.jssystem.it/IT/Prodotti/ATD/Veravox5x.htm
Its not cheap and the freq. response isn't perfectly flat BUT it has a very low energy storage signiture because of the low mass. Hobby HiFi did a set of measurements on this driver and the CSD is VERY clean and the freq. response from 300 to 3k is reasonably flat.
Per Skanning will put whatever cone on his motors that can be fit in there. All you have to is ante up for the fitment $ work. Describe what you want, and he'll make it. He doesn't mind, he gets to experiment at your expense. Only the off the shelf drivers use their proprietary poly cones. However, the poly designs are from years and years of experimentation. They're tough to beat. I have an advantage, though.
I'm working at the molecular design level in coatings and materials, so I can make what ever stiffness modification I desire, If I want to go through the mind bending effort of doing so. All the tools are directly in my face on a daily basis.....I get a headache just looking at it, so i tend to not bother. But that is going to change soon.
As for notches, high slopes, and uncontrolled resonance, etc, we can easily hear 50-70-db down in the mix with a good speaker so the high slope requirements simply don't cut it, with the more aware audio crowd. Sorry. Noise and phasing are screwy with that high slope stuff, I can hear them from a mile down the hallway at an audio show and can easily tell that there is a low slope crossover in use in the given room I am about to enter at said show.
High excursion brings high back EMF, which means incredibly wild impedance swings. This means that high slope crossover can explode with noise and distortion far faster than any low slope crossover, but all slopes and designs are guilty to some degree. One has to decide what overall average SPL they are going to design the crossover for, all SPL are handled differently by the crossover, another layer of mostly unrealized distortion characteristics, specifically by the novice, usually (but not always!). Dynamics and distortion are invariably rise ina more more linear fashion with output in a low slope crossover due to the Back EMF, and this parameter is critical to the human ear. Score one big huge one, for low slope, right there. Besides the better resonance control.
I will also add that I am not stupid enough to think there is only one driver in the world like some retarded Apple PC user feels about apples, simply because they can't get their head around PC's..
AT is great, but I'd jump ship in a heartbeat if I thought there was a better driver around. (Business is business, but association and relationship is priceless) However, I like Per, and would spend the time to see what alternatives can be thought up, if ever such a thing were to occur.
I'm working at the molecular design level in coatings and materials, so I can make what ever stiffness modification I desire, If I want to go through the mind bending effort of doing so. All the tools are directly in my face on a daily basis.....I get a headache just looking at it, so i tend to not bother. But that is going to change soon.
As for notches, high slopes, and uncontrolled resonance, etc, we can easily hear 50-70-db down in the mix with a good speaker so the high slope requirements simply don't cut it, with the more aware audio crowd. Sorry. Noise and phasing are screwy with that high slope stuff, I can hear them from a mile down the hallway at an audio show and can easily tell that there is a low slope crossover in use in the given room I am about to enter at said show.
High excursion brings high back EMF, which means incredibly wild impedance swings. This means that high slope crossover can explode with noise and distortion far faster than any low slope crossover, but all slopes and designs are guilty to some degree. One has to decide what overall average SPL they are going to design the crossover for, all SPL are handled differently by the crossover, another layer of mostly unrealized distortion characteristics, specifically by the novice, usually (but not always!). Dynamics and distortion are invariably rise ina more more linear fashion with output in a low slope crossover due to the Back EMF, and this parameter is critical to the human ear. Score one big huge one, for low slope, right there. Besides the better resonance control.
I will also add that I am not stupid enough to think there is only one driver in the world like some retarded Apple PC user feels about apples, simply because they can't get their head around PC's..
AT is great, but I'd jump ship in a heartbeat if I thought there was a better driver around. (Business is business, but association and relationship is priceless) However, I like Per, and would spend the time to see what alternatives can be thought up, if ever such a thing were to occur.
It's the guy's name. The family name of the creators of 'Audio Technology', or 'AT'.
His dad was part of Dynaudio, but first was the creator of, obviously..."SKAN-speak (Skaaning) and then his own company of cost no object designs, called 'Audio Technology'. His name is 'Ejvind Skaaning'. His son's name is "Per Skaaning". His son (Per) runs the company now. They are Danish, thus the name spelled the way it is.
http://www.flexunits.com/iz.asp?id=4|a|583|||#
Audiotechnology is a family owned company founded by Ejvind and Per Skaaning. Our production facilities are situated in Stilling, Denmark. Ejvind Skaaning was the guiding force behind several loudspeaker companies in Denmark; among the most prominent are Scan-Speak and Dynaudio corporations, both founded by Mr. Skaaning.
And I always spell Ejvind Skaaning's name wrong.
Except this time.
edit: This damn google search engine is following me around, dammit! It seems my posts these days, when they are more than a few minutes old, are already picked up by the goggle spyder. That's the third time in a week that I've searched for something, only to find my own post!! The one I've just made!! I was looking on how to spell 'Ejvind', and my older post, not more than 3 hours old showed up. I've had them show up when they are 20 minutes old. either I'm being my usual paranoid self, or this is happening to everyone else as well.
His dad was part of Dynaudio, but first was the creator of, obviously..."SKAN-speak (Skaaning) and then his own company of cost no object designs, called 'Audio Technology'. His name is 'Ejvind Skaaning'. His son's name is "Per Skaaning". His son (Per) runs the company now. They are Danish, thus the name spelled the way it is.
http://www.flexunits.com/iz.asp?id=4|a|583|||#
Audiotechnology is a family owned company founded by Ejvind and Per Skaaning. Our production facilities are situated in Stilling, Denmark. Ejvind Skaaning was the guiding force behind several loudspeaker companies in Denmark; among the most prominent are Scan-Speak and Dynaudio corporations, both founded by Mr. Skaaning.
And I always spell Ejvind Skaaning's name wrong.
Except this time.edit: This damn google search engine is following me around, dammit! It seems my posts these days, when they are more than a few minutes old, are already picked up by the goggle spyder. That's the third time in a week that I've searched for something, only to find my own post!! The one I've just made!! I was looking on how to spell 'Ejvind', and my older post, not more than 3 hours old showed up. I've had them show up when they are 20 minutes old. either I'm being my usual paranoid self, or this is happening to everyone else as well.
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