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Old 19th Jun 2021, 5:08 pm   #4
John_BS
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Join Date: Dec 2008
Location: Wincanton, Somerset, UK.
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Default Re: Curved v. Straight Sided Speaker Cones

I'm not a loudspeaker designer, but I've been on the periphery of the design process. As Duncan says, straight-sided cones remain rigid to a higher frequency, other things being equal, but the break-up (= colouration) , when it does happen, is generally not nice.
The pseudo-parabolic profile results in increased rigidity at the point where the voice-coil attaches, and this is "good" in general for reducing unwanted modes, and the flare of the cone results in more controlled break-up at higher frequencies. There will also be less energy arriving at the cone surround, where the aim is to produce a reflection-free absorption.
I do recall that the BBC, when designing the drive unit for the LS5/9 monitor, spent months refining (by trial and error) the profile at the point of voice-coil attachment. This was a Polyprop cone which was vacuum-formed on an aluminium former produced in-house by the model shop.
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