Careful. The higher impedance means the output circuit is designed with that in mind.

With a lower impedance speaker, the sound will be much louder with higher distortion, However it will cause the output stage to be driven harder, resulting in failure. there has to be a reason why they chose that impedance.

I deal with this every single day in the car audio world, people hooking up 1 ohm loads to 4 ohm stable amplifiers and blowing them up.