I see that someone mentioned my recommendation I usually make of the Behringer B2030P speakers and twin subs.
This really is the very best speaker in existence that will fit into this price range. This speaker is both far superior for the price in regards to physical construction/parts used and in measured performance in relation to how human hearing perceives sound quality and to how a room loads acoustically in regards to the former. The main unusual strengths of the B2030P are: it's off axis frequency response is almost exactly the same at any extreme angle, from the midbass up to the highest treble. This means that the speaker's direct sound to your ears will match the acoustic ambiance/room reflected sound very closely. When these two match closely, it sounds more realistic to human ears because in real life, the off axis ambient and direct also usually matches very closely with most sound sources: the human perception system is based in this regard to pattern/repetitive learning. When there is a mismatch to such a characteristic, the human perception system detects this and registers it as incorrect, there by degrading the experience in this limited/isolated characteristic. The other benefit of the B2030P over many others, is it's very clean energy decay, in both the cabinet and drivers. That is, the sound at all frequencies decays very quickly after a signal has stopped in comparison to most other speakers. Now, this is very good in this speaker: tops for it's price range - this in comparison with it's off axis response make for a spectacular budget speaker. The speaker has good distortion vs. SPL performance when crossed at 75Hz or higher. It is fairly efficient, and will work well with even 50 watts of clean power per speaker. Of course, the more clean power the better.
I don't recommend products seriously like this on low reliability pure subjective basis like most people. I use my knowledge of speaker design and my extensive knowledge of the related human perceptual research on how humans perceive the measured/objective characteristics.
You really do not want 'big' speakers. At this price point, the huge enclosures act like speakers themselves, emitting resonance from the walls overlapping the direct sound from the drivers. This is still the case with the small speakers, but the much smaller surface area emits much less sound in comparison. The less cabinet emitted sound the better in regards to the true detail/resolution of the sound and the ability for the speaker to convey accurate timbre of different instruments/voices.
Twin subs are useful for increased dynamic ability. But more importantly, if this system is for music, then the twin subs are CRITICAL to provide a seamless bass sound for things like bass guitars and drums and other lower frequency based sound sources. You may read things like twin/stereo subs are myth; no stereo information exists down that low. But it really has not too much to do with stereo information. It has to do with basic sound source physics. If soundwave at cross point from sat to sub is X in length, then you must have the two crossing drivers within 1/2 of X distance for them to sum at and around cross point as an even, proper time integrated virtual source. For this condition to be true, a single sub would have to be placed directly in the middle of both left and right speakers, and then, this would only work in small rooms; not medium or large sized ones - the distance would still be too great. This is also often the worst place for a sub acoustically, resulting in very weak bass response. The practical solutin is placing one sub within 3-4 feet maximum distance from each satellite if crossed at 75-80Hz(the lowest frequency that the B2030P should be crossed), and this case, the subs and sats will act as one virtual 3 way stereo speakers.
For your price range, the Dayton powered 10" or 12" subs are the absolute best performing/quality subwoofer you can purchase to my knowledge. I believe right now that partsexpress is offering free shipping on these, or you can also buy them from audioholics.com's own store.
Please remember, that no matter which advice you choose to follow in a thread like this, that the recommendations of each different person is not necessarily of equal quality/consideration of variables. But rest assured, that if you pay close enough attention, that you should be able to detect which advice is most solid in these regards.
-Chris
