How to calculate weight "seen" by a voice coil

[magnasanti]

I want to know how to calculate the weight "seen" by the voice coil in this transducer. Link -

http://imgur.com/tAO4wE0.

They way the speaker is arranged is there are 12 slats of carbon fiber attached to a thrust bearing on the topside and a voice coil on the bottom. An extra 24 neoprene slats cover and seal the inside. The weight of eacth carbon slat is .26 x 12 is 3.12 grams. The weight of the neoprene is 9.8 grams and the weight of the voice coil is 4.2 grams what would be the weight that the voice coil would have to move?

 

[Ron]

You need to convert sound pressure from decibels to either psi or pascals. Google it.

 

[IRstuff]

> the mass of the structure
> the friction of the bearings
> the desired sound pressure
coupled with the inefficiency of the transducer

TTFN
faq731-376

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[Timelord]

I think what you really want is the inertia of all the moveable parts together with the spring rate of the suspension. These will give you the dynamic force the voice coil has to overcome to accelerate. You can then calculate the response force to known input forces from the coil. It is probably a good bet that the spring rate is symmetrical except for gravity when oriented vertical.

Timelord

 

[magnasanti]

Hey guys thanks for all of the replies. I really want to figure this out. How would converting spl to psi do anything? The mass of the entire structure is 17.12 grams. There is no friction as the slats of carbon are rigidly attached to the bearing there is no movement here. I dont care what the sound pressure is just how much the neoprene weight is effecting the voice-coil. As this is a piston speaker there are two factors both mass and compliance. But due to the fact that the voice-coil is bending the carbon and the carbon is holding the voice coil in place I am pretty confused on exactly how to calculate the weight of the neoprene that the voice coil actually has to "see". Time Lord you seem to be the closest. So you believe the spring or compliance is symmetrical bending and compressing? with the exception of gravity?

 

[1gibson]

What type of frequency response are you looking to get?

 

[magnasanti]

The expected possible frequency is something like 250hz to 7Khx