The premium HK sound system is actually very good in terms of the speakers themselves. The problem is the amplification that’s included. I had two independent amps added behind the backseats on the back wall and pulled all 18 speakers through one, dedicated the subwoofer to the other, and I couldn’t be happier. The clarity, highs, mids, and lows are spot on, and the overall sound is amazing! You don’t have to replace the speakers and you don’t have to spend a whole lot on decent amps. I spent a total of $800, $550 for the two amps and $250 for labor. The guys at my local audio shop are excellent, and they knocked it out in less than two hours.