It’s a 2 Ohm speaker with no good reason.
It's not a 2 ohm loudspeaker. KEF lists it at 4 ohms. Many loudspeakers dip down to 2 ohms, not that unusual. The phase angle is pretty manageable in the low impedance region. It happens.
Kef Reference 1 Meta Impedance Puzzle
Gang,
I’m still stuck on this speaker and it’s terrible and odd impedance curve. It’s a 2 Ohm speaker with no good reason. I should point out, I don't own them and have no interest in buying them, it's a purely academic puzzle for me.
I’m wondering if someone can help me by measuring the impedance of the top and bottom sections separately? If you use REW this may be easy for you to do. A kind and generous soul (Erin’s Audio?) at ASR posted this, but it’s got me more curious. On top of the ludicrously poor (i.e. low) impedance for most of the bass and midrange it’s also not the impedance plot of a ported speaker. Ported speakers characteristically have 2 humps in the bass impedance. One at the port resonance and another at the woofer resonance This has one. What on earth?
Alternatively, if anyone can send me a picture of the crossover that would be a great start.