I have to disagree with your 'no'.
The total surface area of a cone is higher than a flat diaphram of the same diameter - agreed?
That means that more air is in immediate contact with the cone's surface - right?
Upon vibrating back and forth, that cone's shoving more air, cupped in the cone up to its surround, and emitted from the speaker.
The more air that is moved for a given cone movement translates to more room air moving as well.
Dayton LS-1044
and multiple other manufactures
make flat cone subs.
Other than not knowing a array of exact models.
I caught them in different searches.
But I would say " Slim profile"
or shallow mount woofer or sub woofer.
Might bring more results.
Without technical backing, I understand
why the Kef drivers and similar Kef passive drivers
have a following. It is a different aesthetic and look.
Something different to move air and see.
speaker building is sound and art. visually and
technically.
Something different can be intriguing.
or fun to design around.
you could even explore passive radiators.
with flatter profile. to combine modern driver performance
and a different look.
Yes, but a comparison was being made, hence my challenge. Never mind weight issues, that's a different topic.
And as I mentioned before - it's a trendy marketing feature used by multiple manufacturers.
For anyone who's interested...
A flat 12 inch round disk has a surface area of 113.1 inches.
A cone of 12 inches at its outer diameter and 2 inches deep has a surface area of 232.3 inches.
This is of course barring any centrally located things like a voice coil, which would then change things (minus) by a few inches at best.
So a 5mm movement of each would substantially lend to the cone having approx twice the air movement.
No need to further pick with things like surround material, coil diameter, etc.
A cone moves more air, period.
A flat 12 inch round disk has a surface area of 113.1 inches.
A cone of 12 inches at its outer diameter and 2 inches deep has a surface area of 232.3 inches.
This is of course barring any centrally located things like a voice coil, which would then change things (minus) by a few inches at best.
So a 5mm movement of each would substantially lend to the cone having approx twice the air movement.
No need to further pick with things like surround material, coil diameter, etc.
A cone moves more air, period.
Precision Power used to have flat piston subs.
https://www.onlinecarstereo.com/CarAudio/p_11200_Precision_Power_PRO-12.aspx
It's actually a disadvantage. A flat surface has to be more rigid to not flex with perpendicular load than a cone. Therefore it has to use more material, making it heavier. Therefore it needs a bigger motor structure with a more powerful magnet. So, it ends up costing more just to achieve equal performance to a cone.
https://www.onlinecarstereo.com/CarAudio/p_11200_Precision_Power_PRO-12.aspx
It's actually a disadvantage. A flat surface has to be more rigid to not flex with perpendicular load than a cone. Therefore it has to use more material, making it heavier. Therefore it needs a bigger motor structure with a more powerful magnet. So, it ends up costing more just to achieve equal performance to a cone.
You appear to be very confused, sorry, quite apart from your cone surface-area calculation arithmetic.
Sd is the effective piston area, not the physical surface area of the front face. It is the volume of air displaced, divided by the stroke, i.e. the projection of the piston surface onto the plane perpendicular to its stroke. Note also that it's a small-signal that is measured indirectly (via SPL and impedance effects etc), not geometrically with a ruler.
If your hypothesis worked, we would see extremely deep cones to "gather more air"... but no.
Speakers are cones purely because that is a nice rigid shape that can be driven from the centre, i.e. the transverse wave speed across the cone is higher than it would be on a planar piston face, so you can get to higher frequencies before breakup modes become a problem.
Very confused?
Established, documented physics must be confused then, because that's what I'm discussing.
I'm not talking about an "extremely deep cone" here.
I'm talking about an average 12 inch speaker cone-shaped diaphram about 2 inches in depth to the voice coil, as an example, as upposed to a flat one.
Whilst I respect your undoubted experience, a simple thought experience proves you to be incorrect on this issue.
Imagine an internal combustion engine with flat pistons, and that same engine with recessed pistons crowns, in a cone shape if that's easier. Does the capacity of the engine change?
Alternatively with a speaker in a sealed enclosure, is the pressure in the box - for a given speaker excursion - increased, decreased, or remain equal for a flat vs conical piston?
If you have 'documented physics' to prove your hypothesis we would be interested to learn something.
Picture a cone speaker sealed to a short pipe of area equal to Sd, and a flat passive radiator sealed to the other end. (Isobarik mounting in other words). In your scenario, the flat PR would exhibit nearly twice the excursion of the cone as the latter has more air 'cupped in the cone'.
So there is a range of cone angles outside which the 'cupping' effect does not work?
Still no. Please re-read my previous post: Sd is not the surface area of the cone, it is the effective piston area, which is independent of the depth profile. Arguing that a cone has more geometric surface area, while true, is not the same as being able to say that Sd - and therefore efficiency - is higher.
If you want to tell us that a cone moves more air than a flat piston, you will need to show us two otherwise-identical speakers, one with the cone filled in and the other with extra mass (so that they have the same moving mass), and show that small-signal measurements of Sd differ between the two.
232.3 sq inches is the total of the area of the flat base of the cone and the "conical" part.
The area of the "conical" surface is 119.2 sq inches.
I suspect the main performance difference of a cone versus a flat plane is that the additional mass of the air in a cone will alter the measured mms. (This assumes the cone and the flat plane both have the same mass.)
The ratio of the cone surface area divided by the disc surface area is equal to the cone slant height divided by the disc radius. In this case 6.325/6 = 1.054. The cone surface area is 5.4% greater than the disc area.
Cones are way stiffer and pistonic from Fs to the larger of the VC's or dustcap's diameter, so no reason to 'fix what ain't broke'. 😉