E30 Zone

Ive just installed a stereo and its all working fine but i noticed the heat sink get ridiculously hot, i put a small drop of water on it to see how hot it was and it instantly sizzled and evaporated. Is this normal or have i done something very wrong?

'Speaker impedance too low for the amp?

Im not sure what you mean?

Stereo will state a minimum impedance (measured in ohms) for the 'speakers, somewhere in the instructions and/or on the unit itself. 'Speakers will also have a stated impedance.
That of the speakers must be higher or equal that on the stereo.

Ohhh its powering the original bmw speakers so ill have a look again tonight thatnks again.