cotjones
10+ year member
CarAudio.com Veteran
anyone with jl subs (mainly w6's and w7's) ever had a problem with small circles in the center of the cone forming?
i believe i know the reason they form....
as you probably know the subs implement a "W CONE" which basically means the voice coil attaches to the cone in the outside and the center instead of just the center...
this design is important because it makes the cone assembly VERY rigid even with a light weight material...
but there is a problem with this design...
if you compare the outer and inner supports of the "W", you'll notice that the inner are much shorter than the outer... i did a ms paint drawing for it below:
so notice: (B>A)
so both the length and angle of attachment make the inner portion of the cone more rigid than the outside...
the result, is that at extreme excursion the outside of the cone flexes more than the inside, creating that little circle in the center that alot of people seem to notice...
notice also that the wider the diameter of the voice coil is, the less of a difference there is in the length of the supports "A" and "B"...
ironic that jl custom makes their own OVER-SIZED voice coils...
most of you probably didn't care about this, but i thought it was kinda interesting how one improvement in design leads to another
i believe i know the reason they form....
as you probably know the subs implement a "W CONE" which basically means the voice coil attaches to the cone in the outside and the center instead of just the center...
this design is important because it makes the cone assembly VERY rigid even with a light weight material...
but there is a problem with this design...
if you compare the outer and inner supports of the "W", you'll notice that the inner are much shorter than the outer... i did a ms paint drawing for it below:
so notice: (B>A)
so both the length and angle of attachment make the inner portion of the cone more rigid than the outside...
the result, is that at extreme excursion the outside of the cone flexes more than the inside, creating that little circle in the center that alot of people seem to notice...
notice also that the wider the diameter of the voice coil is, the less of a difference there is in the length of the supports "A" and "B"...
ironic that jl custom makes their own OVER-SIZED voice coils...
most of you probably didn't care about this, but i thought it was kinda interesting how one improvement in design leads to another
