Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
Interesting. The response from the SEOS12 is as I would expect between 1kHz and 6kHz, but above that, it has more rolloff than it should have just from mass. There's 20dB drop from 6kHz and 10kHz, more than 18dB/octave. This would only happen if voice-coil inductance and the front chamber conspired to rolloff at the same point, and they're usually staggered, with mass starting around 4kHz, inductance around 12-16kHz and front chamber just above that.
Could be that the phase plug is blocked with debris, or maybe the diaphragm is misaligned. You might open the compression driver and check it out. Sometimes just taking it apart and putting it back together fixes that kind of thing.