Coolzo
500+ Head-Fier
Well, if you don't mind saving up more per speaker (~$450USD for the pair), the Adam F5 will be a direct improvement from the JBL LSR305. Same size speaker, but with much better highs and lows (carbon fiber woofer and ribbon tweeter). I've demo'd these side-by-side, and they are the best bang for your buck if you want small speakers with good bass extension. JBLs come close though, so I'd still recommend those if you prefer to stay around $300. You could also check out the Emotiva Airmotiv 5s and Airmotiv 6s, which are on sale right now. Haven't heard them myself yet, but Ive heard lots of good things about them (they have a design similar to the Adam speakers)
My experience with inexpensive subwoofers hasn't been the best. They often sound very bloated to me even when calibrated correctly, and they don't go that much deeper than these studio monitors.
