Summary: I am thoroughly impressed by how powerful these speakers are. They have a very clean crisp sound. I replaced the old stock speakers from my '96 Toyota Corolla and these speakers are exponentially better. I know I was replacing almost 20 year old speakers, however I can now hear the music over the road noise of an almost 20 year old car. I am very impressed.
Pros: Clean and crisp sound. Better all around speakers
Cons: Everyone complains about there is no bass but what do you expect from a 5" speaker.
Summary: Easy install, great sound improvement all across the sound spectrum. Will have to install subwoofer for better bass definition, but I am satisfied for now. Speakers are exactly what I expected, they are awesome for the money.
Summary: I needed to replace my factory speaker in a older car and the Polk Audio db501 speakers are a great replacement. They bolted into the facory locations without any modifications required. These little speakers sound great.
Pros: Crutchfield said they would fit my application and the speakers sound great for their 5 inch size.
Cons: Frequency response lacking on the low end. I will need to install a sub woofer.
Summary: After ordering, I worried that these wouldn't be enough for my Avalon, was thinking I should have ordered 6" speakers instead. But I installed these anyhow, and couldn't be happier. Great sound, with good bass response even without a subwoofer.
Pros: Price, ease of installation with existing wiring
Cons: The holes don't completely line up with existing holes from 1997 Avalon factory speakers. But still easy enough to install by drilling new holes.