Stumbled across this dd in rides gallery

[Team TH (Donny) 10+ year member]

I dont know how effective it is at focusing a magnetic field. And I can only assume the field is weaker, since there is less magnetic material. You could stack higher, but coil height would be a factor as well. perhaps someone like sundownz or splaudio could chime in with more info on this motor type.

I could see that playing a role as to why they don't build this way as much.

 

[SPLaudio 5,000+ posts]

that motor design is great for cooling but bad for bl (motor force). it can be a great design for a sq sub like a focal though with no mechy noise, air noise like alot of subs make of the air passing thru the pole or perimeter venting around the coil.