Obviously talking about input impedance. In practical terms what this means
is that if you fit a pair of 4 Ohm speakers, you're only just going to get
half the desired output (read volume), which is a real pain.

"Mike Smith" > escribió en el mensaje
...
> JP Roberts wrote:
>> I'm sure you know this, but if you're planning to keep the original head
>> unit, its output impedance is not the standard 4 Ohms. I seem to remember
>> it was 2 Ohms.
>
> Huh? These days, any solid-state amp that costs over two bucks oughta
> have an output impedance measured in tenths or even hundredths of an ohm.
> If you mean that the Audi head unit is designed to drive a 2 ohm *input*
> impedance, well, that's a good thing, not a bad thing, and should pose no
> problem when driving 4-ohm speakers. Meanwhile, if you're talking about
> the line-level output impedance, rather than the speaker-level output,
> then 2 vs. 4 ohms ain't gonna mean a thing - the input impedances of
> today's separate amps tend to be up in the tens of thousands of ohms.
>
> --
> Mike Smith