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Suicide Bobb
12-06-2010, 12:53 AM
Mods: I think you should sticky this, or suggest another title for the thread and sticky the new thread. This will reduce a lot of threads that ask "How many X sized speakers does it take to equal the cone area of nX sized speakers?" and also hopefully be a quick reference sheet for even the experienced to look at.

THESE NUMBERS ARE NOT EXACT! I rounded for almost all of the numbers, and for the charts that compare X speakers to nX speakers, I only picked those that were closely related in cone area. Since my calculator does not have a Pi function, I multiplied the radius squared by 3.14, which as most of you know is close enough. This chart is only meant to give you an idea of how similar the cone area of X speakers is to nX speakers.

As you can tell, I only went for common sized speakers. I'm not going to include speakers like the ear-shaped Yamaha woofer, or some one-off sub like the custom MTX Thunder 1,000,000. The sizes I chose are those of known production speakers (off the top of my head). Please let me know of any that I left out, and I will update each category to include them.

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One Speaker

Diameter of speaker | Cone area of speaker in square inches

34" ---> 908
32" ---> 804
22" ---> 380
21" ---> 346
18" ---> 254
15" ---> 192
13.5" ---> 143
12" ---> 113
11" ---> 95
10" ---> 79
8" ---> 50
6x9 ---> 42
6x8 ---> 38
6.5" ---> 33
4x10 ---> 31
5x7 ---> 28
5.25" ---> 22
4" ---> 13
3.5" ---> 10
2" ---> 3

--------------------

Two Speakers

X Speaker | Equivalent of 2X Speakers

3.5" ---> 5.25"
4" ---> 5x7
5.25" ---> 6x9
5x7 ---> 8"
6x8/6x9 ---> 10"
8" ---> 11"
10" ---> 13.5"
11" ---> 15"
12" ---> 18"
15" ---> 22"
22" ---> 32"

--------------------

Three Speakers

X Speaker | Equivalent of 3X Speakers

2" ---> 3.5"
3.5" ---> 5x7/4x10
4" ---> 6x8/6x9
5x7 ---> 10"
4x10/6.5" ---> 11"
6x8 ---> 12"
8" ---> 13.5"
10" ---> 18"
12" ---> 21"
18" ---> 32"

--------------------

Four Speakers

X Speaker | Equivalent of 4X Speakers

2" ---> 4"
3.5" ---> 5x7/4x10
4" ---> 6x8/6x9
8" ---> 15"
10" ---> 21"
11" ---> 22"
15" ---> 32"

Suicide Bobb
12-06-2010, 12:55 AM
This chart displays the relationship between odd shaped subwoofers and circle subwoofers. You may know the triangle and pentagon subwoofers from Bazooka and Xtant, respectively, and the 24" square subwoofer as the new MTX Jackhammer.

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Pentagon

One Subwoofer

Diameter of Cone | Cone Area in square inches

10" ---> 74

---------------------

Pentagon

Two Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 2X Subwoofers

10" ---> 13.5"

--------------------

Pentagon

Three Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 3X Subwoofers

10" ---> 15"/18" (between the two)

--------------------

Pentagon

Four Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 4X Subwoofers

10" ---> 18"/21" (between the two)

--------------------

Triangle

One Subwoofer

Diameter of Cone | Cone Area in square inches

10" ---> 48
12" ---> 86

--------------------

Triangle

Two Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 2X Subwoofers

10" ---> 11"
12" ---> 15"

--------------------

Triangle

Three Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 3X Subwoofers

10" ---> 13.5"
12" ---> 18"

--------------------

Triangle

Four Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 4X Subwoofers

10" ---> 15"
12" ---> 21"

--------------------

Square

One Subwoofer

Diameter of Cone | Cone Area in square inches

8" ---> 64
10" ---> 100
12" ---> 144
15" ---> 225
18" ---> 324
24" ---> 576

--------------------

Square

Two Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 2X Subwoofers

8" ---> 12"/13.5"
10" ---> 15"
12" ---> 18"
15" ---> 24"

--------------------

Square

Three Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 3X Subwoofers

8" ---> 15"
10" ---> 18"/21"

--------------------

Square

Four Subwoofers

X Subwoofer | Circle Subwoofer Equivalent of 4X Subwoofers

8" ---> 18"
10" ---> 22"
12" ---> 34"

--------------------

CHEMMINS
12-06-2010, 01:06 AM
2 15's is considerably larger than 1 21".

RAM_Designs
12-06-2010, 01:11 AM
hmmm...

Suicide Bobb
12-06-2010, 01:11 AM
2 15's is considerably larger than 1 21".

That was one of the ones I was iffy about. It's about 40 cubic inches difference, which is about 10% marginal error. I don't think that it would be audible?

Thanks for the input! Anyone else feel free to help improve this!

RAM_Designs
12-06-2010, 01:12 AM
2 15's is considerably larger than 1 21".

And four 10's is pretty much exactly the same sd as one 18, not one 21.

CHEMMINS
12-06-2010, 01:16 AM
And four 10's is pretty much exactly the same sd as one 18, not one 21.

4 10's would be 314......no?

RAM_Designs
12-06-2010, 01:26 AM
4 10's would be 314......no?

I'm just going off of Fi's specs. 1240cm^2 for the four 10's and 1210cm^2 for the 18.

OP: If you're going to do the whole pi(r^2) thing, take 3" off of each normal-sized woofer's diameter since you have the mounting ring and surround on each side to consider when looking for a somewhat accurate idea of the cone size.

Or just look around for normal sd measurements on different size woofers.

1rockford1
12-06-2010, 01:41 AM
so 2 8s same as 1 12? gona do 4 8s instead of my 4 12s.looks like im gona lack the cone area i guess

Suicide Bobb
12-06-2010, 01:46 AM
And four 10's is pretty much exactly the same sd as one 18, not one 21.

79*4=316
18"=254
21"=346

Suicide Bobb
12-06-2010, 01:50 AM
I'm just going off of Fi's specs. 1240cm^2 for the four 10's and 1210cm^2 for the 18.

OP: Sd isn't just a flat thing that you can measure by looking at the radius of a woofer, cone angle comes into play as well. And if you're going to do the whole pi(r^2) thing, take 3" off of each normal-sized woofer's diameter since you have the mounting ring an surround on each side to consider when looking for a somewhat accurate idea of the cone size.

Or just look around for normal sd measurements on different size woofers.

Alright buddy, you're making things waaaay too technical :) Like I said in the title, the measurements are not exact.

You are going by the cone area of a specific subwoofer, whose basket is measured to be 8/10/12/15/18". My chart compares ACTUAL cone area, so it rules out angle, surround width, etc.

If I measured your way, I would be required to put every single sub ever made in existence, separately, on this chart. I'm sorry bruh, but I don't have the time for that lol

Suicide Bobb
12-06-2010, 01:52 AM
so 2 8s same as 1 12? gona do 4 8s instead of my 4 12s.looks like im gona lack the cone area i guess

Nope :/ 2 8s is similar to 11". The marginal error of 2 8s to 1 12 is about 13%. Honestly though, that's not gunna be an audible difference, but still.

1rockford1
12-06-2010, 01:59 AM
Nope :/ 2 8s is similar to 11". The marginal error of 2 8s to 1 12 is about 13%. Honestly though, that's not gunna be an audible difference, but still.

so i should b ok then. im gona do 4 8s tune to 32 instead of 4 12s sealed. the power will b the same i just will b doing four lower rms subs that will see close to there rated power where my 12s where seeing about half there rated power with my curent amp. thanks good write up might i add my luv

Suicide Bobb
12-06-2010, 03:23 AM
so i should b ok then. im gona do 4 8s tune to 32 instead of 4 12s sealed. the power will b the same i just will b doing four lower rms subs that will see close to there rated power where my 12s where seeing about half there rated power with my curent amp. thanks good write up might i add my luv

Yeah, good idea. It's fun to showoff to all the caraudio noobs you know, then tell them you're running 8's :)

Thanks! It took hours upon hours, so I'm glad at least someone appreciates it...

Suicide Bobb
12-06-2010, 03:24 AM
Updated the first and second posts to include the Jackhammer 22" (first post), and the square, pentagon, and triangle subwoofers. Again, feel free to critique!

Tomorrow, or whenever I find time next, I will go through and display the marginal error for every equivalence comparison. Other than that, I think that pretty much covers it!

audioholic
12-06-2010, 03:46 AM
I'm just going off of Fi's specs. 1240cm^2 for the four 10's and 1210cm^2 for the 18.

OP: Sd isn't just a flat thing that you can measure by looking at the radius of a woofer, cone angle comes into play as well. And if you're going to do the whole pi(r^2) thing, take 3" off of each normal-sized woofer's diameter since you have the mounting ring an surround on each side to consider when looking for a somewhat accurate idea of the cone size.

Or just look around for normal sd measurements on different size woofers.Cone angle, sometimes referred to as cone depth, does not alter cone area of a speaker. A massively deep speaker with an OD of 12" has no more effective radiating surface than does a flat coned 12. You can ignore cone angle completely, and basically just look at cone diameter to compare different drivers. The only thing using the simple method of calculating Pi*r^2 will miss is the surround and how it affects the radiating surface area.

Suicide Bobb
12-06-2010, 03:51 AM
Cone angle, sometimes referred to as cone depth, does not alter cone area of a speaker. A massively deep speaker with an OD of 12" has no more effective radiating surface than does a flat coned 12. You can ignore cone angle completely, and basically just look at cone diameter to compare different drivers. The only thing using the simple method of calculating Pi*r^2 will miss is the surround and how it affects the radiating surface area.

There you are, you wise *** nga! Was waiting for your arrival and *hopefully* approval...

audioholic
12-06-2010, 04:14 AM
There you are, you wise *** nga! Was waiting for your arrival and *hopefully* approval...

Like I said above, I generally just use Pi*r^2 to compare speaker sizes. That method is accurate enough for 99% of the situations. But if your chart makes it easier for other people to understand, yes I definitely approve. Having the odd shaped cones' area was a nice touch as well.

Suicide Bobb
12-06-2010, 05:09 AM
Like I said above, I generally just use Pi*r^2 to compare speaker sizes. That method is accurate enough for 99% of the situations. But if your chart makes it easier for other people to understand, yes I definitely approve. Having the odd shaped cones' area was a nice touch as well.

Well that's the method I used as well, and it works!

The Pentagon one was a beezy to figure out. Had to use my algebra and trigonometry skills (or lack thereof) together to figure out the apothem and side length. Oh, and Google :)

Think of this thread as a cheat sheet of sorts. You already know the formula, but it may be more practical to just peruse the cheat sheet instead :)

RAM_Designs
12-06-2010, 07:02 AM
My chart compares ACTUAL cone area
How is this again?

If I measured your way, I would be required to put every single sub ever made in existence, separately, on this chart. I'm sorry bruh, but I don't have the time for that lol
Considering that nearly every woofer is close to being a half inch larger than it's listen size(ie: 12.5" for a 12" sub), it's really pretty easy to do.

RAM_Designs
12-06-2010, 07:04 AM
Cone angle, sometimes referred to as cone depth, does not alter cone area of a speaker. A massively deep speaker with an OD of 12" has no more effective radiating surface than does a flat coned 12. You can ignore cone angle completely, and basically just look at cone diameter to compare different drivers. The only thing using the simple method of calculating Pi*r^2 will miss is the surround and how it affects the radiating surface area.
Weird, for some reason I had it in my head that it did matter. I'll edit my poast.

helotaxi
12-06-2010, 09:36 AM
If you want it to actually mean anything, right now it doesn't, yo u have to account for th surround and the fact that a 12" sub may only have a 10" cone. The smaller the speakers the bigger the difference the surround makes. The basic math based on nominal speaker size is easy but also pointless since it really doesn't give you a meaningful answer. A better chart would be to actually look through a bunch of manuals that list Sd for various drivers and build a chart from that. It would actually mean something and provide a valid comparison between sizes.

Suicide Bobb
12-06-2010, 05:00 PM
If you want it to actually mean anything, right now it doesn't, yo u have to account for th surround and the fact that a 12" sub may only have a 10" cone. The smaller the speakers the bigger the difference the surround makes. The basic math based on nominal speaker size is easy but also pointless since it really doesn't give you a meaningful answer. A better chart would be to actually look through a bunch of manuals that list Sd for various drivers and build a chart from that. It would actually mean something and provide a valid comparison between sizes.

and...take years to compose. The list I provided, for the last time, is not exact! It never was meant to be. It's only meant to give people a general idea of how cone A compared to cone B. This is not for competitors, those looking for xxx.xdb, etc. It's just a guide to help people decide on a setup or generalize a comparison. If you want to grab 100 drivers of each size and average out their respective actual cone area, then I'll redo it with those numbers. But even still, that's just as far off as my comparison, because if someone with an Earthquake DBX-12 and Orion NT-12 look for numbers, it will still fall short because of the large difference in their cone areas.

I would love to make a list concerning every make and model of speaker ever made, but I just don't have the time. Someone would have to pay me a whole lot of money to do that!

RAM_Designs
12-06-2010, 05:15 PM
Going by listed sd, four 10's is still almost exactly = to an 18" sub, not a 21" sub. I'll give you another example besides the Fi one I did before. Mach 5 IXL's: 266cm^2 for the 10", 1029cm^2 for the 18". Four 10's would be 1064cm^2, which is within ~3.5% of the 18" figure.

Suicide Bobb
12-06-2010, 06:17 PM
Going by listed sd, four 10's is still almost exactly = to an 18" sub, not a 21" sub. I'll give you another example besides the Fi one I did before. Mach 5 IXL's: 266cm^2 for the 10", 1029cm^2 for the 18". Four 10's would be 1064cm^2, which is within ~3.5% of the 18" figure.

That is because your are doing what HeloTaxi said and accounting for the surround. That means that their 10" is likely more like a 8", and their 18" is more like a 16".

RAM_Designs
12-06-2010, 06:28 PM
That is because your are doing what HeloTaxi said and accounting for the surround. That means that their 10" is likely more like a 8", and their 18" is more like a 16".

So you don't want to do it the right way and use accurate, real life specs instead of guessing and using your own method that doesn't come up with the same answer? Just going off of the sd provided by Fi for the SSD, a lot of your conversions are not really right, and some just can't be made. Like a pair of 12's is closer in sd to a single 15 than a single 18. Three 10's is not that close to a single 18.

It's too easy to just use the stated sd for a given line of speakers and use that to make comparisons.

BlactimusCrime
12-06-2010, 06:33 PM
why dont people understand this is NOT MEANT TO BE ACCURATE, JUST A ROUGH ESTIMATE FOR NEWBS OR LAZY PEOPLE. there are too many subs that vary too much to make an extremely accurate comparison. this does the job for most people for a general idea.

If you care that much, then find the subs you want to compare, gather youre info and get out your calculator.

Good job Bobb, keep it up.

helotaxi
12-06-2010, 06:37 PM
And RAM-Designs proves my point exactly. You can still make generalizations. If you look at the Sd of a handful of different 8s for example they are all going to be pretty close. There might be some outliers on either side but just looking at the Sd of a single driver of average design will give you the information that you need. Until you bother to do that, your chart is pointless and misleading. I hope that the mods DO NOT STICKY it.

RAM_Designs
12-06-2010, 06:38 PM
why dont people understand this is NOT MEANT TO BE ACCURATE

Then why do something that isn't meant to be accurate? And like I have stated, some are quite off. Next thing you know noobs will be say that three 10's = the same cone area as a single 18.

RAM_Designs
12-06-2010, 06:41 PM
there are too many subs that vary too much to make an extremely accurate comparison.

Within the same speaker line, the same generalizations that I stated can be made. IE: four 10's = one 18. Three 10's is pretty close to a pair of 12's. Three 12's is about 10-15% more sd than a single 18...etc.

Suicide Bobb
02-14-2011, 07:23 PM
Thanks for the sticky MoT!

cheeto
05-26-2011, 01:40 PM
Suicide Bobb's has a lot more info for different size speakers, I made this one a few years ago to measure circular cones against each other. Colors are used to see how many of one size it would take to get the same cone area with another size.

http://i.imgur.com/ZZqSf.png

And again as was argued before this isn't supposed to be accurate. Of course the cones are smaller than the basket size and I didn't account for the surround, but if I did the ratios would still be roughly the same, therefore the colors are still accurate.