Something that doesn't distort when cranked has less to do with the speaker and more to do with the amplifier. When you hit distortion you're at the top of the power curve on the amplifier. You're out of the noise but into distortion meaning that clean sine wave you were amplifying is now flattened on the top (clipped). Your speakers attempt to play the clip and it sounds like crazy monkey farts. Get an amplifier to go with that head unit of yours. You might find that you like the speakers you already have.