Cone area with high roll surrounds..

[sean skar15]

I recently purchased 2 zvx-15s and it occurred to me that most SPL subs have a large, high excursion, surround that is 2-3" wide. Thus subtracting from the useable cone area. Many moons ago when it was Rockford Fosgate, alpine, JL, and so on.... the surrounds were 1/2" wide, 1" at the most when Eclipse introduced the aluminums. We all know there is a sound difference between 8s, 10s, 12s or 15s. I feel each size has its own unique sound as 2 10s  still do not give the sound of a 15" Measuring the cone area on the zvx-15 I noticed it's only 10". Useable area of 12" at the most, including half the surround. Does this mean, if I wanted actual 15" I need to buy 18"? If I wanted 12" then buy the 15s?

Click to read more...

 

[Popwarhomie 5,000+ posts]

WTF....

 

[shredder2]

Once I figured out how to read the op's post... I agree with the first comment

 

[sean skar15]

Go measure the cone area of a zvx-15" woofer and its only 10" . That leaves 2.5" of surround on both sides. 

 

[Popwarhomie 5,000+ posts]

k?

 

[THATpurpleKUSH 5,000+ posts]

Cone area is measured from middle of the surround to the middle of the surround on other side. 

 

[Dragonsyph]

There also deeper.

 

[sean skar15]

Cone area is measured from middle of the surround to the middle of the surround on other side. 

Right, thats what I was taught. So this 15" is actually a 12" woofer.

 

[PPVtahoe11]

Lmao measure any woofer. They all measure smaller then they are.  Skar just *****. Sorry for your purchase. Also a 10” woofer sounds just like a 15” woofer. Idk what your trying to say in your first post 

 

[Keith1069]

I do know that cone area vs. oversized surround is very close in comparison with movement of air volume. Cone area everyone should understand that the more you have the more air you move. Oversized surround is like this, If your sub has oversized surround, then more than likely it has a longer voice coil, deeper basket and larger spider. This means that there is more linear movement which can displace a whole lot of air. They usually have more bass, and deeper bass. I had 1 DD 3512 that would destroy many different brands of 15's with standard surround, including kicker L7's. If you want deeper bass, more SPL, Oversized surround is the thing now.

 

[THATpurpleKUSH 5,000+ posts]

Right, thats what I was taught. So this 15" is actually a 12" woofer.

View attachment 4989

View attachment 4990

I guarantee if you calculate tsp parameters with a Klippel or Dayton DATS, the number you get for sd is within the realm of other comparable15s. The piston is always smaller than the nominal size, but sd is the most accurate parameter when considering cone area. 

 

[nate0]

There is nothing to debate here. 

You could always play it till it pops and then recone trying to get your 1" back on both sides. You won't get much more than that though.  Actually skar only carries recones for the zvx models, so you can't really recone it with anything they sell, but I am sure you could find one some where.   

 

[yamomluvsme]

I recently purchased 2 zvx-15s and it occurred to me that most SPL subs have a large, high excursion, surround that is 2-3" wide. Thus subtracting from the useable cone area. Many moons ago when it was Rockford Fosgate, alpine, JL, and so on.... the surrounds were 1/2" wide, 1" at the most when Eclipse introduced the aluminums. We all know there is a sound difference between 8s, 10s, 12s or 15s. I feel each size has its own unique sound as 2 10s still do not give the sound of a 15" Measuring the cone area on the zvx-15 I noticed it's only 10". Useable area of 12" at the most, including half the surround. Does this mean, if I wanted actual 15" I need to buy 18"? If I wanted 12" then buy the 15s?

Orginally the SD was measured differently some companies used 1/2 the surround(when real accurate testing methods started to be implemented) and some used 1/4 of the surround(more accurate than 1/2 because those companies used linear roll surrounds which where the same height and width to provide a linear stiffness over stroke).. when I do build I use strictly a baseline of the actual diaphragm. Reason being is the diaphram creates a high and a low pressure that creates a pressurized "wave" of air. 

The surrounds do very very very little to aid in the linear piston stroke. Ideally you want just the piston to create the actual pressurization the surround adds nonlineariarites to the sound/wave. While piston area is definitely important more important is the woofers design and using it for it's intended purpose. Ie you can get that 15 to get loud as si.ilar 18s if you utilize it correctly.