speaker surgery: reduce winding height

[capslock]

In an active configuration where one does not care too much about absolute sensitivity, it might be attractive distortionwise to reduce the number of turns, i.e. change an overhung design to underhung or make an underhung one more underhung. The other downsides are even lower impedance (which I am assuming the amp can handle) and possible more power compression (which could be countered with current drive).

Specifically, a midrange with 6 mm gap and 8 mm winding height might be better off with just 2-4 mm winding height.

How does one go about this surgery? Unwinding turns definitely forces one to remove the VC and hence spider and surround. Besides, there is the danger of deforming the former. I wondered if it would be possible to put a scratch into the isolation of the outer (top and bottom) turns and short-circuit them with some solder. In some very open designs such as Seas or Vifa XT, this would be possible without taking the speaker apart.

Issues:
- mass stays the same
- outer windings act as short circuit brake: I am not sure whether this is a disadvantage, some PA drivers to this to limit overexcursion, and I read that this reduces distortion (which I profoundly doubt!)
- it would be impossible to apply this technique to the buried layers of multilayer VCs, but I think if the shorted top windings acts as a short circuit to AC fields, they will effectively short circuit the lower layers also


What do you think?

[kelticwizard]

Originally posted by capslock
In an active configuration where one does not care too much about absolute sensitivity, it might be attractive distortionwise to reduce the number of turns, i.e. change an overhung design to underhung or make an underhung one more underhung....

...Specifically, a midrange with 6 mm gap and 8 mm winding height might be better off with just 2-4 mm winding height.

Fewer turns in the gap should lead not only to lower sensitivity, but higher Qes, Qts, (and eventually Qtc), as well.

Since you don't care that much about sensitivity, perhaps you can compensate for this with enclosure design.