Has anyone ever tried

[ZacharyP]

Wiring the sex up for a 4k primary?  Would there be any benefits, or would it require further tweaking of the circuit and component values?

Or, is it just not worth pursuing at all?  Thanks for reading, as always

[Paul Joppa]

It is already set up for that. Just use a speaker of half the target impedance - 8 ohm speaker on the 16 ohm wiring, etc.

You should get more distortion, more power, and less damping of the speaker (especially bass).