Sub woofer cone area chart

[Sir-Lancelot 216]

I cant take credit for this, I found it on another forum and saved it.

[ssh 924]

Here's another chart, may be easier to read

[Aaron Clinton 2,372]

Thank you guys, time to pin.

[Kanaworm$ 292]

Nice find guys!

[cheese20323 13]

Nice Charts! for the people thinking 2 10's is 1 20" sub....

[Shogen 325]

hmm... nice charts.. so more cone area will somewhat relate to more air movement/ louder sound??? I'm just asking..

[cheese20323 13]

hmm... nice charts.. so more cone area will somewhat relate to more air movement/ louder sound??? I'm just asking..

Yeah. But Motor Force is another factor Along with others....

[jcarter1885 995]

hmm... nice charts.. so more cone area will somewhat relate to more air movement/ louder sound??? I'm just asking..

Yeah. But Motor Force is another factor Along with others....

x2, usually if the subs are in the same line-up then yes it will move more air and be louder. Such as if you were comparing a 15" Fi Q to 2-12" Fi Q's then yes more cone area wins.

[helotaxi 46]

Too bad the charts are completely wrong. They are calculated assuming that the entire diameter of the sub is usable cone area when that isn't nearly the case. They don't even really give a ballpark comparison between sub sizes either since a 1" wide surround on an 8 will have a much greater effect on Sd than a 1" surround on a 12.

[Impious 1,476]

Too bad the charts are completely wrong. They are calculated assuming that the entire diameter of the sub is usable cone area when that isn't nearly the case. They don't even really give a ballpark comparison between sub sizes either since a 1" wide surround on an 8 will have a much greater effect on Sd than a 1" surround on a 12.

I was just getting ready to say the same thing. The formula they used is to find the area of a circle. Unfortunately you can't calculate cone area by finding the area of a fixed number (8, 10, 12, etc), since only a portion of the surround is considered "cone area" and two different subs will not necessarily have the same physical dimensions.

The cone area (Sd) for a loudspeaker is accurately stated as:

Sd = (Pi * D^2)/4

Where D is the diameter of the cone plus 1/3 of the surround at both ends of the measurement.*

*Some manufacturers will use 1/2 of the surround instead of 1/3 for the measurement, which would make the Sd of the driver appear larger. So in reality, the Sd listed by two different manufacturers is not directly comparable unless you know the same method of measurement (1/3 or 1/2 of the surround) was used for each driver.

For example, a 12" Fi BTL has an Sd of 480cm^2, which is 74.4in^2, which according to the chart is less than the Sd of a 10" driver. Work backwards to find the radius, sqrt(74.4/3.14) = 4.87in. Which means that the effective piston diameter of the driver is only ~9.75", not 12" as the chart would want you to use. And if the BTL had a larger or smaller surround, then it's Sd would decrease or increase, respectively.

Which means that, unfortunately, those charts are pretty much useless

[Sir-Lancelot 216]

Sorry guys!

[klee7013 10]

dont feel bad i was thinking the same thing last night

[Aaron Clinton 2,372]

I did not even check them. Would anyone like to adjust them with both 1/2 and 1/3 surround if they have the time? That way we can have an accurate chart.

[ssh 924]

so two 10"s do in fact have more surface area then an 18"? just kidding.

Well you learn something new everyday. Thank you helotaxi and impious for enlightening me

[ssh 924]

I did not even check them. Would anyone like to adjust them if they have the time? That way we can have an accurate chart.

It would change from driver to driver depending on the surround, So unless we make a chart for individual drivers?

[Robert.Metzel 4]

Its not on the money but it does show how to get the most bang for your buck. So the numbers would just be a bit smaller if measured properly, but 1-18 should always have more cone area then 2 -12's for example; and this is what it shows. Its a generalized chart for comparisons.

[bassahaulic 155]

Too bad the charts are completely wrong. They are calculated assuming that the entire diameter of the sub is usable cone area when that isn't nearly the case. They don't even really give a ballpark comparison between sub sizes either since a 1" wide surround on an 8 will have a much greater effect on Sd than a 1" surround on a 12.

I was just getting ready to say the same thing. The formula they used is to find the area of a circle. Unfortunately you can't calculate cone area by finding the area of a fixed number (8, 10, 12, etc), since only a portion of the surround is considered "cone area" and two different subs will not necessarily have the same physical dimensions.

The cone area (Sd) for a loudspeaker is accurately stated as:

Sd = (Pi * D^2)/4

Where D is the diameter of the cone plus 1/3 of the surround at both ends of the measurement.*

*Some manufacturers will use 1/2 of the surround instead of 1/3 for the measurement, which would make the Sd of the driver appear larger. So in reality, the Sd listed by two different manufacturers is not directly comparable unless you know the same method of measurement (1/3 or 1/2 of the surround) was used for each driver.

For example, a 12" Fi BTL has an Sd of 480cm^2, which is 74.4in^2, which according to the chart is less than the Sd of a 10" driver. Work backwards to find the radius, sqrt(74.4/3.14) = 4.87in. Which means that the effective piston diameter of the driver is only ~9.75", not 12" as the chart would want you to use. And if the BTL had a larger or smaller surround, then it's Sd would decrease or increase, respectively.

Which means that, unfortunately, those charts are pretty much useless

And both of you beat me to it lol

[Shogen 325]

Maybe it is asking too much but:

1. Can you guys make this chart specific to SSA line-up?

2. Do it for the Sundown SA series as well?

I'd attempt it myself but my math would be wrong... 1+1 = 11, yes?

[Dictator1992 6]

haha tru **** would be cool to see the actual cona are raiduis of either of those companies line up's would be cool.

[ssh 924]

Someone please correct me if I did anything incorrectly, I just used the Sd values from the ssa homepage

I'll make another for SA when I got a minute.

[Dutchie. 10]

How about the Fi line-up. That would be a good one to have

[ssh 924]

How about the Fi line-up. That would be a good one to have

Some of the fi drivers have the same Sd value listed on their site as the icons and xcons have.

Perhaps if I have time and theres enough demand, and im doing it right, then i'll make a condensed chart for ssa, sundown, and fi

[Dutchie. 10]

How about the Fi line-up. That would be a good one to have

Some of the fi drivers have the same Sd value listed on their site as the icons and xcons have.

Perhaps if I have time and theres enough demand, and im doing it right, then i'll make a condensed chart for ssa, sundown, and fi

Good stuff man thanks, and I have no clue your guess is as good as mine.

[bigmikekc 2]

yeah a fi chart would be tight

[Impious 1,476]

I guess for starters I really don't see the point behind any of these charts. Not to devalue stephan's work.....but com'on, it's basic math that anyone capable of successfully operating a computer should be able to figure out on their own in a matter of minutes with a calculator. It would probably take more time to pull up a chart than it would to just figure it out by hand. I mean seriously, would people really not be able to figure out the area of more than one circle, then compare that number to another, on their own without use of a chart? Can someone not look on the companies website for Sd, multiply it by the number of drivers they want to use, and do the same for a different sized driver and then compare the two? If someone can't manage to figure out this little bit of information on their own, then they should probably to revisit elementary school as that is where the basic skill sets required to accomplish this feat are acquired.

Its not on the money but it does show how to get the most bang for your buck. So the numbers would just be a bit smaller if measured properly, but 1-18 should always have more cone area then 2 -12's for example; and this is what it shows. Its a generalized chart for comparisons.

My main issue with the use of that chart, aside from the laziness required to even need to use that chart, is that it is teaching people wrong information. It may be close enough for government work....but it's still wrong. And if it's teaching novices wrong information, then that will simply confuse them more. They'll be missing out on a basic but fundamental concept. Cone area is a simple driver parameter, that is apparently disturbingly misunderstood. It'll only make things worse if we start them off by teaching them wrong information. When you were in school, your educators hopefully didn't teach you that Pi was 3 since that's "close enough" (there have actually been laws passed throughout the years to attempt to change the "officially recognized" value of Pi in various states and localities....ignorance abound).

Second, there can actually be a fairly significant difference in Sd between two same sized drivers. If we assume there's no difference by using incorrect values for determining area, then we are again missing important details. A 12W7 for example has approximately 1db worth of additional cone area than the SSA drivers listed above. That's breaching the realm of audibility, due simply to difference in cone area between two different "twelve inch" drivers that the original chart completely ignores.

Last, most people interested in cone area are trying to determine potential output differences. Cone area alone is useless for this purpose. For that, you would need to know Vd not just Sd. In order to obtain an accurate Vd, you would need an accurate Sd and Xmax. Using inaccurate Sd will misrepresent potential output capabilities and differences. Again, making the information useless and teaching novices wrong information.

Overall, I can't think of a single reason to suggest or recommend the use of wrong information.