I dunno if these are the best but the Wharfdale Diamonds 8.2 active are pretty sweet, they have great highs and mid range the extreme lows are lacking though so if your doing hip hop your gonna need some bigs to double check the lows. But I don't think there's any speaker under 600 thats replicates the extreme lows accurately
You could get them from a fellow Home recer deepwater for a great price around $300 if things haven't changed. PM him