Speaker cone shape


Why are speakers cone shaped, apart from rigidity? To my mind the air being pushed by a cone would radiate at an angle inward toward the axis of the speaker and collide in the centre, which seems inefficient to me, and likely to cause some distortion of the sound. This may also cause interference to adjacent speakers on the same baffle.  Would there be any advantage to having the surface flat, assuming you could maintain rigidity without increasing the mass? There must be modern capable materials out there.
Is the fact that the speaker is cone shaped that causes the volume to change counter intuitively as you move left and right in front of the speakers? What I mean by counter intuitively is when you move left the right speaker sounds louder and visa versa.
chris_w_uk

Showing 1 response by mijostyn

Thank you vinylfan62! Someone finally came up with the right answer. Talking about lay instinct gone awry. Air is not moving. It is pressure fronts that are moving. A flat woofer radiates exactly the same way as a conical one. The physical characteristics of the drivers are different but that is all. This might lead to different driver behaviors and distortion characteristics. Nobody has been able to out perform the conical driver in bass and midrange applications for dynamic drivers.  It is an inherently stiff structure so it is easier to keep it light. Attempts at using alternative  structures have been relative failures. The old paper cone still reigns supreme but you also have composites, metal, ceramic and diamond cones and domes. You also have various suspension types, voice coil formers, methods of ventilation and voice coil cooling (ferrofluid), and basket structure. There is no magic in any of this.

The real problem for dynamic drivers is that their dispersion characteristics change dramatically with frequency relative to the size of the driver. The frequency band is not dispersing uniformly but continuously changing. Some people believe speakers that disperse uniformly over a narrower area have better imaging characteristics as opposed to speakers that will disperse widely but unevenly across the frequency band.