Hi Guys,
I've spent the last few days looking through datasheets for a high output 10" midrange, and I've noticed a few things in my search:
1. Some manufacturers have incredibly pathetic datasheets for their drivers
2. Some (very few) manufacturers have extremely good datasheets for their drivers
3. Most manufacturers have mediocre datasheets for their drivers.
This got me to thinking about why we, as consumers, accept and purchase a product based on so little information? Why don't we insist that driver manufacturers run a FULL suite of standard measurements on ALL of their products? I feel the following should be the mandatory minimum:
1. Frequency Response - On Axis, 15 degrees, 30 degrees, 45 degrees, 60 degrees (IB, 1m, 2.83V, anechoic)
2. Distortion vs. frequency - 1W and 10% rated power 2nd-5th harmonic
3. TS parameters (all of them)
4. Impedance vs. Freq
5. Full mechanical drawing with all dimensions
6. Volume occupied by driver
7. Reference to all test conditions
Nice to have:
1. Klippel measuements: Le(x), Bl(x) etc...
2. Power compression
3. Suggested (and tested) alignments
I know the above is a little vague, but it at least covers the basics. For an example of a truly superb datasheet, check out what Selenium does:
http://www.jblselenium.com.br/site/assets/produtosfinal/270_pdfManual.pdf
I struggle to find anything missing from the selenium datasheet other than the Klippel stuff.
In contrast, check out what PHL, Volt and AEspeakers offer:
http://www.phlaudio.com/datasheets/25_pdf/3860.pdf
Volt Loudspeakers - About Us
AE Speakers Online Store
I struggle to find anything of value in these datasheets. They've put more effort into taking pictures of the driver than actually providing useful information (in the case of Volt, they didn't even bother to take pictures). If they can't take the time to post a proper frequency response, then how on earth did they design a proper driver? If they don't have the facilities to measure their products correctly, then should they really be selling transducers to the world at large? In my mind, only one of the following two things can be true:
1. They have proper measurements but have chosen not to provide them because they aren't very good.
2. They don't have proper measurements, and therefore should not be designing drivers.
Does anyone have any suggestions about what could be done to improve the situation? Anything I've missed above that should be included?
If you know of other manufacturers with shameful datasheets, post them here so we can persuade them to change!
I'm all ears.
Cheers,
Owen
I've spent the last few days looking through datasheets for a high output 10" midrange, and I've noticed a few things in my search:
1. Some manufacturers have incredibly pathetic datasheets for their drivers
2. Some (very few) manufacturers have extremely good datasheets for their drivers
3. Most manufacturers have mediocre datasheets for their drivers.
This got me to thinking about why we, as consumers, accept and purchase a product based on so little information? Why don't we insist that driver manufacturers run a FULL suite of standard measurements on ALL of their products? I feel the following should be the mandatory minimum:
1. Frequency Response - On Axis, 15 degrees, 30 degrees, 45 degrees, 60 degrees (IB, 1m, 2.83V, anechoic)
2. Distortion vs. frequency - 1W and 10% rated power 2nd-5th harmonic
3. TS parameters (all of them)
4. Impedance vs. Freq
5. Full mechanical drawing with all dimensions
6. Volume occupied by driver
7. Reference to all test conditions
Nice to have:
1. Klippel measuements: Le(x), Bl(x) etc...
2. Power compression
3. Suggested (and tested) alignments
I know the above is a little vague, but it at least covers the basics. For an example of a truly superb datasheet, check out what Selenium does:
http://www.jblselenium.com.br/site/assets/produtosfinal/270_pdfManual.pdf
I struggle to find anything missing from the selenium datasheet other than the Klippel stuff.
In contrast, check out what PHL, Volt and AEspeakers offer:
http://www.phlaudio.com/datasheets/25_pdf/3860.pdf
Volt Loudspeakers - About Us
AE Speakers Online Store
I struggle to find anything of value in these datasheets. They've put more effort into taking pictures of the driver than actually providing useful information (in the case of Volt, they didn't even bother to take pictures). If they can't take the time to post a proper frequency response, then how on earth did they design a proper driver? If they don't have the facilities to measure their products correctly, then should they really be selling transducers to the world at large? In my mind, only one of the following two things can be true:
1. They have proper measurements but have chosen not to provide them because they aren't very good.
2. They don't have proper measurements, and therefore should not be designing drivers.
Does anyone have any suggestions about what could be done to improve the situation? Anything I've missed above that should be included?
If you know of other manufacturers with shameful datasheets, post them here so we can persuade them to change!
I'm all ears.
Cheers,
Owen
When they spec very precise then it can lead to claims of costumers when there are tolerances.
Also it will be easy to compare products and costumers choose the best looking spec.
You shout look in the professional corner. They spec also Thd like Beyma does. Although it depends on how you use it.
Also it will be easy to compare products and costumers choose the best looking spec.
You shout look in the professional corner. They spec also Thd like Beyma does. Although it depends on how you use it.
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I would disagree with this, especially for the manufacturers listed. I doubt PHL or AEspeakers sell a whole lot of thier products to OEMs. Individual consumers probably make up a respectable percentage of thier portfolio either directly or indirectly through resellers like E-speakers. Manufacturers like JBL and Selenium, however, certainly can't be bothered with DIY enthusiast, but interestingly they have the best datasheets.
That is all beside the point, however, as they still need to sell the drivers to somebody, and whoever that somebody is, they will eventually need that data! It doesn't matter if you're an OEM or a guy building a box in his garage, the owness should always be on the driver manufacturer to provide proper documentation.
Regards,
Owen
Yes, no data will eventually lead to a rotten egg and bad marketing.
Frd/zma's for all new drivers starting today.
Frd/zma's for all new drivers starting today.
agreed, they really are in general pretty crap, i'm at the moment searching around for a reasonably high end mid-woofer narrowed down to the ubiquitous Scanspeak 18W 8531 G00 and the AudioTechnology C-Quenze 18 H 52 17 06 SD KAP
now the C-Quenze has got one of the more useless datasheets i've seen consisting of the below and a simple FR graph without even an impedance vs frequency plot. you can customise the C-Quenze as far as magnet size, former type, sandwich cone and a midrange surround if you wish, OEMs can change a few more for a minimum order i presume. these are great drivers and the extras dont come cheap, but they hardly tell you how the standard form performs, let alone give you enough information to choose the extras. for example they make a big deal about the carbon/paper sandwich cone, but there is no data on a unit that has it vs not. hell, there isnt even any data on one that has it.
Granted they may provide all this info on request if you know the right questions to ask, but as far as the datasheet its really bad. even the physical dimensions page, for which they have a dedicated page, has very limited info.
God help anyone wanting to specify a Flex unit, however the flex units i can understand a bit, due to there being so many variables and a certain level of knowledge is assumed when buying a driver of this level. given their reputation and mainly OEM market perhaps its mostly by request. but when asked to spend nearly 1000 each on a 6.5" mid-woofer i expect some better info on the front page
the SS is somewhat better, but still not what you expect from a brand that is so widely used and by DIY as well.
C-Quenze 18 H 52 17 06 SD
Resonance frequency - fs: 40 Hz
Equivalent volume - Vas: 28,5 liter
Qms 1,8
Qes 0,39
Qts 0,32
Nominal impedance - Zn 8 Ohm
DC resistance - re: 5,6 Ohm
Effective cone area - Sd: 137 cm2
Compliance – Cms: 1,09 mm/N
Mechanical resistance – Rms: 2,04 kg/s
Moving mass – mms: 14,6 g
Inductance 1 KHz – Le: 0,13mH
Force factor – Bl: 7,3 N/A
Winding height – Hc: 17 mm
Air gap height – Hg: 6 mm
Nominal power – Pn: 150 W
Acceleration factor: 499
Efficiency – SPL: 89 dB
so that plus a FR graph is it!! WTF?
now the C-Quenze has got one of the more useless datasheets i've seen consisting of the below and a simple FR graph without even an impedance vs frequency plot. you can customise the C-Quenze as far as magnet size, former type, sandwich cone and a midrange surround if you wish, OEMs can change a few more for a minimum order i presume. these are great drivers and the extras dont come cheap, but they hardly tell you how the standard form performs, let alone give you enough information to choose the extras. for example they make a big deal about the carbon/paper sandwich cone, but there is no data on a unit that has it vs not. hell, there isnt even any data on one that has it.
Granted they may provide all this info on request if you know the right questions to ask, but as far as the datasheet its really bad. even the physical dimensions page, for which they have a dedicated page, has very limited info.
God help anyone wanting to specify a Flex unit, however the flex units i can understand a bit, due to there being so many variables and a certain level of knowledge is assumed when buying a driver of this level. given their reputation and mainly OEM market perhaps its mostly by request. but when asked to spend nearly 1000 each on a 6.5" mid-woofer i expect some better info on the front page
the SS is somewhat better, but still not what you expect from a brand that is so widely used and by DIY as well.
C-Quenze 18 H 52 17 06 SD
Resonance frequency - fs: 40 Hz
Equivalent volume - Vas: 28,5 liter
Qms 1,8
Qes 0,39
Qts 0,32
Nominal impedance - Zn 8 Ohm
DC resistance - re: 5,6 Ohm
Effective cone area - Sd: 137 cm2
Compliance – Cms: 1,09 mm/N
Mechanical resistance – Rms: 2,04 kg/s
Moving mass – mms: 14,6 g
Inductance 1 KHz – Le: 0,13mH
Force factor – Bl: 7,3 N/A
Winding height – Hc: 17 mm
Air gap height – Hg: 6 mm
Nominal power – Pn: 150 W
Acceleration factor: 499
Efficiency – SPL: 89 dB
so that plus a FR graph is it!! WTF?
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i can give you a direction if you like to listen ...
check the past ...go 30-40 years ago do you expect company like JBL to have 40 years ago the computing power you have in your house as we speak ? Absolutely NOT ...Expect that some of best speakers in the world manufactured with some... experience some calculation ... a lot of tests based on listening ... and generally a study based in actual principals like the above .
Can tell if hose speakers was the best in the world but be sure that the approach was the basis for today's speakers ....
Now days you have powerful software tools to tell you what to do and you need to feed them with data...so out of the blue the data needs keep increasing every day
.....Like in solid state they have powerful tools to design and simulate amplifiers ...Tools are so powerful that they may tell you how the speaker will behave if your floor is made of tiles or you may notice the changes on the software tool when you replace the tiles with carpet....
in the year 1970 was a young kid asking my father who was actually a blacksmith ( bit more advanced in the metal rectify business ) after seen the SPACE 1999 serial :
((Dad ? what is a "computer" that we see on the serial ?))
the blacksmith said :
(( don't know my son i presume though that is a machine that if you feed it crap you will get crappy results ))
Very prophet-able i think for the year 1970....
Happy regards
Sakis
check the past ...go 30-40 years ago do you expect company like JBL to have 40 years ago the computing power you have in your house as we speak ? Absolutely NOT ...Expect that some of best speakers in the world manufactured with some... experience some calculation ... a lot of tests based on listening ... and generally a study based in actual principals like the above .
Can tell if hose speakers was the best in the world but be sure that the approach was the basis for today's speakers ....
Now days you have powerful software tools to tell you what to do and you need to feed them with data...so out of the blue the data needs keep increasing every day
.....Like in solid state they have powerful tools to design and simulate amplifiers ...Tools are so powerful that they may tell you how the speaker will behave if your floor is made of tiles or you may notice the changes on the software tool when you replace the tiles with carpet....
in the year 1970 was a young kid asking my father who was actually a blacksmith ( bit more advanced in the metal rectify business ) after seen the SPACE 1999 serial :
((Dad ? what is a "computer" that we see on the serial ?))
the blacksmith said :
(( don't know my son i presume though that is a machine that if you feed it crap you will get crappy results ))
Very prophet-able i think for the year 1970....
Happy regards
Sakis
Did you see the data from Suprafox? The 215-2000 cost 1200 euro here is the data.
215-2000 SUPRAVOX
They even do not have a nice photo on the site. The distributers support better pictures.
An externally hosted image should be here but it was not working when we last tested it.
May be it is just poor marketing, or a marketing choice so you can't compare till you bought one and measure it your self.
As DIY community we can measure them our self and post the driver data in a suitable topic. Here are many people with all kind of drivers at home. Would make a nice data base.
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to be honest sakis, i'm not quite sure what direction that was intended to take me. the data i posted above is basic for even before computer modelling, not even having a frequency vs impedance plot does not give you the basic data to use as a STARTING point to see whether it will work with your amplifier or favoured crossover type, let alone modelling what effect changing the floor will have.
the physical dimensions tell you that there is 6 holes for bolting it to the baffle, but since it only shows a profile and no point of origin, it does not give you any idea where they are. its crap by any standard, but now taking into account that they themselves will have used sophisticated modelling tools to create this very high end driver and yet give us this and it becomes kinda rude in a way, given the money they want for it, rather than simply inadequate
the physical dimensions tell you that there is 6 holes for bolting it to the baffle, but since it only shows a profile and no point of origin, it does not give you any idea where they are. its crap by any standard, but now taking into account that they themselves will have used sophisticated modelling tools to create this very high end driver and yet give us this and it becomes kinda rude in a way, given the money they want for it, rather than simply inadequate
mostly is supposed to be a joke ... point is that 2% mistake in one parameter or lie or even a printing error will make the speaker misbehave ...
to my point of view you need to listen more and compute less
simulation may be a basis for a design but the actual design cannot be only based to it
Kind regards
sakis
AE speakers is one guy, AFAIK. And they hand make woofers, presumably with off the shelf parts. To compare them with these other companies is silly.
Fs can vary by ~15%, Vas by ~20%. Frequency response and sensitivity are subject to manufacturing changes... Best is to measure.
Now if you called a mfg and gave them specs and said you would order 500 and potentially more, they would probably send you a nice submittal package for approval. 😉
I think it's a fair comparison... they both sell exactly the same product, and neither have acceptable datasheets. It doesn't matter much how many people work at the company, or what parts they use. I'm just one guy, and I very carefully measure everything I design on the electronics side of things. I would never dream of selling something to the public without knowing exactly how it behaved!
It's not like a measurement setup is going to cost $100,000 and can only be achieved by large speaker manufacturers. You could put together a very respectable measurement system for less than $1000 including the cost of the IEC baffle and the computer. Good measurement techniques would allow someone to measure without the need for an anechoic chamber, or better yet, rent time in one from a local lab.
There is NO excuse for not providing good measurement data.
Helmuth:
qusp is correct, that driver is reasonably well specified if you look at the links to the measurements. It was easy to miss though, so I can see how you didn't catch it.
qusp:
The Audio Technology thing is a little difficult since they do specialize in custom units. I wonder if they would be willing to provide you with more data if you told them exactly what you wanted?
As for things like the sandwich cone though, you’re absolutely correct. They shouldn’t be telling you in words how it’s better, when a simple measurement is what they really need to do! If it reduces distortion, then show how it does. If it makes for a smoother FR in the passband, then show that. Instead they say “The result is an extremely rigid and stiff cone, presenting fast, uncoloured and distortion free bass.” which is just a bunch of marketing drivel.
I'm going to start a list for fun... feel free to add to it and re-post it.
Companies with exceptional datasheets:
Accuton
Aura Sound (sometimes)
Eton
JBL
RAAL (sometimes)
Selenium
Wavecor (missing THD, but includes a 3D model)
Companies with good datasheets:
Audax
Audience
Dayton (some sheets are exceptional like the one for the PS220-8)
Fostex
Fountek
Jordan
Markaudio
Morel
Peerless
SB Acoustics
Seas
Vifa
Companies with acceptable datasheets:
Audio Technology
CSS – some are good, others provide nothing at all
Hi-Vi Research
LCY (some are good, but mostly poor)
TB Loudspeakers
Companies with shameful datasheet:
AEspeakers
ATC
Pyle
PHL
Veravox
Volt
ZR Speaker Labs (they have a response, but it uses a 180dB scale to try and make it look flat!)
Cheers,
Owen
All Miss It
Most driver specification sheets are missing key information, as the parameters presented are always given sans tolerances. Without this information you cannot do sensitivity analysis of your design to see how vulnerable it is to driver manufacturing variances as well as changes in ambient temperature and/or relative humidity. At what point can changes to them move your design into a suboptimal operating state? Of most concern is VAS or other Compliance parameter given. It is difficult to control this one due to the variance to be found in the elasticity of materials used to fabricate spider and surround compliances.
Regards,
WHG
Most driver specification sheets are missing key information, as the parameters presented are always given sans tolerances. Without this information you cannot do sensitivity analysis of your design to see how vulnerable it is to driver manufacturing variances as well as changes in ambient temperature and/or relative humidity. At what point can changes to them move your design into a suboptimal operating state? Of most concern is VAS or other Compliance parameter given. It is difficult to control this one due to the variance to be found in the elasticity of materials used to fabricate spider and surround compliances.
Regards,
WHG
Hi,
Useful thread, it may help to get more complete sheets.
I found Beyma's good. And found disturbing that manufacturers like Volt or ATC having so good fame are so poor in giving informations about their products.
Useful thread, it may help to get more complete sheets.
I found Beyma's good. And found disturbing that manufacturers like Volt or ATC having so good fame are so poor in giving informations about their products.
Besides you never knowing the materials the drivers you are buying are made of, like the surrounds are made of foam or rubber, cone material, John Janowitz is very keen to explain to you everything technical or not, as he did in the past in this forum or his, and as a good manager and interested serious person does. So here we have an example of the best products, no doubt, a good record and deficient information, that you can find by/from a third party (in many other cases can be a distributor or sales/buyer doing the work). Interesting to say the least.
AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.
http://sites.google.com/site/drivervault/
oh yeah its true, you can find MUCH better info on many of these products done by amateurs.......
@opc: yeah agreed AT may very well be more forthcoming via email and i fully understand due to the mammoth task as far as the FLEX units go, but the C-QUENZE although allowing a bit of customisation, should at the very least cover the base model, contrasted perhaps with what they consider to be the most worthwhile upgrade.
@opc: yeah agreed AT may very well be more forthcoming via email and i fully understand due to the mammoth task as far as the FLEX units go, but the C-QUENZE although allowing a bit of customisation, should at the very least cover the base model, contrasted perhaps with what they consider to be the most worthwhile upgrade.
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