Review on Polk Audio 5 25 Inch Coaxial Speakers by Dee Parson

Despite good reviews online, they're pretty weak. If you're wondering whether the more expensive Polk MM522 is worth the extra money, the answer is a resounding yes. difference between day and night. The MM522 have much better sound quality, clarity and volume. They are also half as light and look much better. The grill on the db521 isn't very good either. Do yourself a favor and spend the extra money. If you look there are refurbished and open offers, I did and I was very pleased after being so disappointed with the db521 kit. Installed on my 2015 Kawasaki Concours 1400 motorcycle.