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<blockquote data-quote="squeak9798" data-source="post: 5071114" data-attributes="member: 555320">There are several reasons for large motor structures, it&#039;s going to be product-specific on why they chose the motor they did.As was mentioned, Adire openly stated that the motor on the Brahma was oversized simply for cosmetic, and hence sales, reasons.&nbsp; They could have gotten equal performance out of the driver with a smaller motor, but the smaller motor didn&#039;t have the &quot;eye candy&quot; effect that can help sell drivers.Another reason some companies use large magnet structures is that it&#039;s typically cheaper to increase rearward coil clearance with ferrite than it is steel.Another reason might be that it was the most cost effective means of achieving their desired motor strength for the design.Another reason might be, as was mentioned, a slight increase or benefit in coil cooling.One thing to keep in mind is though is that stacking magnets is not an overly effective way of increasing motor strength.&nbsp; I don&#039;t recall the exact figures, but IIRC stacking a 2nd magnet only increases motor strength by ~20% (feel free to correct me if I&#039;m wrong on the %, I know it&#039;s a less than stellar increase).&nbsp; Transferring magnetic force is all about surface area.&nbsp; It&#039;s more effective to widen the diameter of the magnet than it is to stack a magnet in order to increase the force of the motor.&nbsp; But again, this is where cost/benefit is going to come into play.&nbsp; Maybe it&#039;s more cost effect or otherwise beneficial (rearward clearance, cosmetics, etc) to the design of a particular sub to stack as opposed to widen the structure.</blockquote>

[QUOTE="squeak9798, post: 5071114, member: 555320"] There are several reasons for large motor structures, it's going to be product-specific on why they chose the motor they did. As was mentioned, Adire openly stated that the motor on the Brahma was oversized simply for cosmetic, and hence sales, reasons. They could have gotten equal performance out of the driver with a smaller motor, but the smaller motor didn't have the "eye candy" effect that can help sell drivers. Another reason some companies use large magnet structures is that it's typically cheaper to increase rearward coil clearance with ferrite than it is steel. Another reason might be that it was the most cost effective means of achieving their desired motor strength for the design. Another reason might be, as was mentioned, a slight increase or benefit in coil cooling. One thing to keep in mind is though is that stacking magnets is not an overly effective way of increasing motor strength. I don't recall the exact figures, but IIRC stacking a 2nd magnet only increases motor strength by ~20% (feel free to correct me if I'm wrong on the %, I know it's a less than stellar increase). Transferring magnetic force is all about surface area. It's more effective to widen the diameter of the magnet than it is to stack a magnet in order to increase the force of the motor. But again, this is where cost/benefit is going to come into play. Maybe it's more cost effect or otherwise beneficial (rearward clearance, cosmetics, etc) to the design of a particular sub to stack as opposed to widen the structure. [/QUOTE]

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