My pick and recommendation as a great speaker that transitions the gap between audiophile and non-audiophile speaker is the Athena Technologies F2 floor standing speaker that cost $599 a pair.
Actually I am a bit surprised that no one here (or HD) has talked about this speaker. It has more authority and will play louder than any of the other "recommended" budget speakers on these or prior threads on HD (that I can recall). This seems to be VERY important to most non-audiophiles that I know. In my experience many non-audiophiles have an expectation that their new "expensive $600 a pair" speakers have the ability to play pretty extreme sound pressure levels, especially in the bass. Most budget minded audiophile speakers cannot do this and really fall apart when they are eq'd for "better bass" (do you know how many non-audiophiles crank the bass and loudness controls on their receivers? This will destroy most audiophile budget speakers!). The Athena F2's actually have two 8" woofers in a tower acoustic suspension speaker configuration. IMHO this driver complement does a much better at meeting the expectations of the non-audiophile for bass (it works pretty damn well for audiophiles too!).
Another point about the Athenas is they seem to be VERY well balanced and sorted out for a budget minded speaker. I was told that the same development group that made the Sound Dynamics RTS-3 design had a hand in the Athena's development. The RTS-3s are legendary for their midrange that compares with multi-thousand dollar high end speakers (I still am scratching my head on how those desingers pulled this feat off for only $198 a pair). In comparison, the Athena F2's have a better tweeter and far surpass the Sound Dynamics in terms of bass, sound levels, overall refinement and bass definition with less bloat (which was the biggest downfall of the RTS-3 IMHO. Note: The RTS-3's are no longer manufactured). Best of all, it shows that this design group has ears and has figured out a way to achieve decent high end sound on the cheap, with lots of bass to boot!
BTW: I realize that this speaker costs $100 more than the original poster's $500 budget theoretical. I still decided to post this info. because the Athena really achieves so much in terms of bass and loudness as compared to any other budget speaker that I have ever heard anywhere near this price point. Perhaps this information will be appreciated by someone with a slightly higher budget
