Hi guys just wanted to voice my opinion on which speaker I think sounds the best and share a tip on increasing sound quality. I purchased the Alpinestars first and tried them out for a week. They are definitely an improvement over stock but to me had very strange sound. Bass is pretty non existent but can expect much from a 5.25. I'm only running off head unit so I'm sure sound would be much better with an amp. I thought I'd give the polks a try and to me they definitely sound much fuller and are more efficient running off the factory head unit. One thing I did try was adding some poly fill into speaker enclosures and that made a world of difference sweetening the sound and making the bass a bit tighter and punchy. Poly fill I got out of a couple old stuffed animals for free...lol Anyway hope this info helps!