I'd rather two channels working half as hard. The H-K woofers are nominal 4 ohms. You could use a converter to get a line voltage to drive the amp, but it's the same thing as the high level input of the amp. Finding accurate specs on the H-K amp is like herding cats. You would want to run the external amp level high, and keep the bass EQ on the iDrive flat. Each 6dB of EQ boost doubles the amp output voltage, so get the output you want with the external amp, not EQ.
|