DF is limited at low frequencies by the choke in series with the woofer (0.08 Ohm typ.) to about 100 and by speaker wire inductance (0.5uH/ft typ) to about 10. It doesn't make much difference between DF=1000 or DF=4000.
Amp's DF at high frequncies is probably less important. Atmasphere, transformerless tube amp has DF=1.5 and the sound is exceptional (so I heard).
I would stay away from high DF amp (other than class D). High DF requires deep negative feedback - source of TIM and "transistor" sound.
Average power is only few percent of peak power. Only about 5% of this power goes to tweeter. It is rather difficult to destroy tweeter inspite of its small size. Tweeter gets damaged if you play test tones too loud, when your amp is saturating (flattened peaks=square wave=energy in high frequencies) or when your amp (or source) is oscillating at high frequency. The most common is damage caused by saturation when amp has not enough power. The best solution for that is to get amp higher rated than speakers or the amp with so called "soft clipping". Then you will loose woofer, midrange and the tweeter at the same time (just kidding).
Magfan - I've never had Maggies (space issue) but your efficiency doesn't look so bad. What is specified (SPL) at 1m is different at 5m. Typical speaker (point source) drops 6db when distance is doubled, but maggies are not the point source and drop is probably less than 6dB.
As for incredibly high power needed (according to article)at point of speakers impedance drop it is not so bad. The most of power demand in music comes at low frequncies (just look at the size of the woofer)and impedance drop is probably around 200Hz (most likely higher) - only fraction of peak power.
Amp's DF at high frequncies is probably less important. Atmasphere, transformerless tube amp has DF=1.5 and the sound is exceptional (so I heard).
I would stay away from high DF amp (other than class D). High DF requires deep negative feedback - source of TIM and "transistor" sound.
Average power is only few percent of peak power. Only about 5% of this power goes to tweeter. It is rather difficult to destroy tweeter inspite of its small size. Tweeter gets damaged if you play test tones too loud, when your amp is saturating (flattened peaks=square wave=energy in high frequencies) or when your amp (or source) is oscillating at high frequency. The most common is damage caused by saturation when amp has not enough power. The best solution for that is to get amp higher rated than speakers or the amp with so called "soft clipping". Then you will loose woofer, midrange and the tweeter at the same time (just kidding).
Magfan - I've never had Maggies (space issue) but your efficiency doesn't look so bad. What is specified (SPL) at 1m is different at 5m. Typical speaker (point source) drops 6db when distance is doubled, but maggies are not the point source and drop is probably less than 6dB.
As for incredibly high power needed (according to article)at point of speakers impedance drop it is not so bad. The most of power demand in music comes at low frequncies (just look at the size of the woofer)and impedance drop is probably around 200Hz (most likely higher) - only fraction of peak power.