Keep in mind that a higher impedance speakers, say one that peaks at 10 or 12 Ohms but is rated at "8 Ohms", will require more voltage to drive it than one that peaks at 8 Ohms. It won't need as much current at 10 or 12 Ohms obviously, but it will require more voltage. The only way you can get more output voltage is to use a higher wattage amplifier if you going solid state or use a higher impedance tap if you are using a transformer coupled output stage, such as most tube units.
Remember the Dahlquist DQ-10's? They had a relatively low impedance dip but also had a high impedance midrange, so they required both higher current and higher voltage to drive them properly. Not too many amplifiers back in the day could do both.
Remember the Dahlquist DQ-10's? They had a relatively low impedance dip but also had a high impedance midrange, so they required both higher current and higher voltage to drive them properly. Not too many amplifiers back in the day could do both.