Probably never heard a set that someone took the time to actually tune. They're not a simple "drop-in" proposition. You actually have to work with the EQ to get them to sound right. Once they are tuned right, though, the relatively effortless output and dynamics are truly impressive. The best set I heard were one of the original ID horns (cannot remember the model number) with a mono 31-band EQ on each. They were sunk down into the defrost vent at the top of the dash. Seemed like my head was on the edge of a concert stage, it was that good. I have always wanted to try myself. Just have not had the play money or nerve to do it.