I have a DLS A5 and its sub channel is 1.33ohm stable, but since DLS is better than your average amp, do u think it would be able to handle a 1ohm load?
Considering in-box impedence rise along with the fluxuation frequency to frequency and impedence increases due to heat, etc, I'd think you would be OK.
The motor acts as an inductor, there for the inductance that the speaker sees, especially as frequency rises, will cause the impedance to rise well above the Re attribute. Chances are that the amp will never see that one ohm load unless you are free-airing the driver at Fs.