Doki wrote:

I'm looking at fitting some speakers I have lying around to my car. The
thing is, car headunits usually have wattage quoted for with 4ohm speakers.

Indeed.


The speakers I have at 6 ohm. Is this going to lead to a noticeable lack of
volume running a boggo head unit that nominally throws out 25-30WPC RMS, or
am I just going to lose the top end of the range of clipped distorted car
radio horribleness?

You are going to lose about 1.5dB. In other words the loss in power will be
virtually inaudible.

If the 6 ohm speakers are more efficient (see the dB/W @ 1m figures) then it
might even be louder with them.

Speaker efficiency is far more important than a few ohms difference in the
impedance or a few extra watts.

Graham