Cone Area

[actlsub 10+ year member]

How does the xxx have more cone area than the eD A?

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[Warbleed 10+ year member]

It doesn't. The actual Sd of the XXX 15, for instance, is about 760cm^2. The E15A's cone area is about 806cm^2. Anyone who says the XXX 15 has more cone area, is mistaken, or lying...just not possible for it to have more cone area, as it has a smaller diaphragm, since it has a 1.5" surround vs the 1" surround of the A.

 

[actlsub 10+ year member]

k, thats what i thought. Y would RE post that on their websight then. Another question: since there sd is not accurate, then is the xmax of 32mm also imaginary or has it been DUMAX tested?

 

[Randy Savage 5,000+ posts]

Resonant Engineering lists Sd as 810 cm^2 for the XXX 15 ...

I believe the DUMAX said different...

 

[actlsub 10+ year member]

I believe the DUMAX said different...

Snova, u got a copy of the dumax that i could look at, i would like to see it

 

[Randy Savage 5,000+ posts]

Snova, u got a copy of the dumax that i could look at, i would like to see it

nope //content.invisioncic.com/y282845/emoticons/wacky.gif.cf4a48f9e6dfe9504ffd2c946fd2f340.gif

 

[actlsub 10+ year member]

nope //content.invisioncic.com/y282845/emoticons/wacky.gif.cf4a48f9e6dfe9504ffd2c946fd2f340.gif

have u seen the dumax?

 

[Warbleed 10+ year member]

I believe the DUMAX said different...

Yep. Any 15" woofer with that 1.5" wide surround like that is going to have an Sd in the neighborhood of 760-762cm^2. The SP did, the Brahma does, the XXX does, the HC does, etc. Basically all of DeStijl's drivers that use that same surround are going to end up with about that same Sd.

You won't really see much of a significant deviation with any other "1.5 wide roll" surrounds, either.

It's entirely possible that RE used the 1/2 surround method, which is a bit more liberal for estimating Sd, whereas DUMAX uses the more conservative 1/3 surround method.

 

[actlsub 10+ year member]

well then does anyone have the real dumaxed numbers for the xxx???

 

[Bobyota 10+ year member]

What does cone area matter? Louder?

 

[Warbleed 10+ year member]

What does cone area matter? Louder?

To an extent. Displacement really determines maximum output, and cone area is only one part of that equation. You must take bore (Sd) x stroke (xmax) to get displacement.

Neither is very relevant without the other.

 

[Bobyota 10+ year member]

You can have two different 12" subs with different sd's right? Is this just due to how much area the surround takes up?

My old 12's only have 7.68mm xmax //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif I need new subs.

 

[Warbleed 10+ year member]

You can have two different 12" subs with different sd's right? Is this just due to how much area the surround takes up?
My old 12's only have 7.68mm xmax //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif I need new subs.

Not just the surround. Some drivers have the surround spaced somewhat away from the gasket on the outside, whereas others have the surround right up against it.

This is why just taking the diameter minus the width of the surround (x2) doesn't really work, because it doesn't really take everything into account.

Let's take an Eclipse Ti 15, for instance. We have an outer diameter of about 15.7". The gasket and space before the surround begins takes up about 0.75" on each side. So now we're down to 14.2".

When we actually measure the surround, from 1/3 to 1/3, we get a length of about 11.35". So we have a total Sd of only about 650cm^2.

By comparison, we take a driver with a 1" surround and virtually no space between the gasket and surround, such as the E15A, and we get an Sd of about 806cm^2. That's about 25% more cone area.

That means that if we had two drivers with identical motors and suspensions, save we had a 1" surround vs the 2" surround, the driver with the smaller surround would displace about 25% more air, simply by virtue of the smaller surround profile. Now given drivers of similar surround width we'll still have some variations in the Sd, but it'll be very similar to another driver with the same size surround and gasket. Doesn't matter if the diaphragm is conical or flat, same Sd.

 

[Easy E 10+ year member]

The RE XXX uses XBL^2 is very possible that it has 32mm of xmax. XBL^2 can have as much xmax as you want it to be, the technology will give you unlimited amounts of excursion. So that I dont doubt. Have someone buy a new RE XXX then dumax it then, if they are so curious.

Thats my 2 cents.

 

[Warbleed 10+ year member]

The RE XXX uses XBL^2 is very possible that it has 32mm of xmax. XBL^2 can have as much xmax as you want it to be, the technology will give you unlimited amounts of excursion. So that I dont doubt. Have someone buy a new RE XXX then dumax it then, if they are so curious.
Thats my 2 cents.

You should read what I said more closely. The motor IS capable of 32mm of xmax, no problem, but the SPIDER is going to be limited to the 28-30mm range. Xmax is the lowest of Xmag or Xsus.