I have modified khorns I bought an upgrade package from volti audio.
This included all new drivers and new mid-range horns. I also had a new set of crossovers made this greatly improved the sound quality of the khorns.
I feel they sound best with a tube amp and a turntable. With live records the soundstage is amazing!
I have tried other amps and the sound is different with each one try out some different amplifier's till you get what you are looking for.
Happy hunting!!