7. Is it easy to drive the FT1? Can ordinary cell phones drive it?

The impedance of FT1 is 32Ω and the sensitivity is 98dB/mW@1kHz (113dB/Vrms@1kHz). Relatively speaking it is very easy to drive. The computer, mobile phone and other common playback devices are also able to drive it. But if you want to get a better sound performance, it is recommended to use the playback device with higher output power.