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Richard Crowley
 
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"Todd H." wrote ...
Ding! It's a juggling act and there are tradeoffs. Want less
inductance, use fewer turns of wire, but... oops, now you
need more current to achieve the same force to move a given
mass with a given transient response, and ah crap, also need
bigger wire to achieve the now-great power handling requirement,
so you use a better magnet, but that adds cost and/or heft,
perhaps more than your target market will be willing to pay.
And so on on.


Which is why JBL took ordinary (round) magnet wire and ran it
through a home-made kludge that flattened it into a ~rectangular
shape. They pointed out this device on a tour of the factory I took a
couple decades ago. They claimed this exercise allowed them to...

1) Pack more turns (mean cross-sectional area) in a given space
by more efficiently using the space (filling in the corners, etc.)

2) Make self-supporting voice-coils so they didn't have to use
the fiber (paper) coil forms seen in other drivers. I believe they
claimed this allowed smaller gaps (increasing flux) and made
the coils better at shedding heat (no insulating coil form on the
inside of the solenoid).

They had a lathe-like device where they would edge-wind
long solenoids of coil, slathering them with something that
held them together. Then heating the coil and allowing it to
cure (overnight). After that, they could take the big coils
and chop off just the amount needed to make a voice coil
with a bit extra to bring out the leads.

At least that is the way I remember it.