First, a bit about studio monitors for the uninitiated.
If there's one area video guys are usually lacking in it's the sound department. I seldom run across a videographer who has a decent monitoring system. They generally have a line out to a stereo receiver and set of home theatre speakers, or much worse, computer speakers! Hardly the stuff to monitor on. Proper studio monitors are meant to sound flat, unlike hi-fi speakers which are meant to color the sound, and while that may lend itself well to listening to music and DVDs that have already been mixed, that isn't what you want for mixing on. The goal is to have a finished DVD or CD that will sound reasonably good on any system when it's finished, and to do that you need flat sounding monitors that aren't colored in any way.
If you line up six pairs of hi-fi speakers in a row, all with woofers and tweeters etc. of the exact same dimensions, all six will sound different because every manufacturer has their own idea of what a pleasing EQ curve is. But if you align six studio monitors in a row with the same speaker dimensions, they'll all sound reasonably similar because the goal, after all, is for them to have as flat an EQ curve as possible. That said, no two sound exactly identical, though the differences are slight compared to hi-fi speakers. One may have a slightly more pronounced bass end, another a tweeter that's a little harsh sounding and so forth. Sometimes you don't notice these differences until you've been listening to them for a while. You may find that the new monitors you just bought that sounded so good in the show room start to give you ear fatigue after an hour of mixing, whereas another pair may hold up all day. There's a lot that goes into what affects the monitor's sound such as the construction materials used (especially the tweeter material) and the presence of a bass port and how the port is done etc.
Okay, end of preamble.
REVIEW: After my power amp blew last winter, instead of buying a new one, I decided to give a set of KRK Rokit Powered 6 G2 Limited Edition Studio monitors a try. I've been living with them day in and day out for a solid year now, so I'm finally ready to give an opinion about them. In the 6 to 8" woofer category, these monitors are quite good. They don't have the harshness of the similarly sized Yamaha, Mackie, or M-Audio units. The bass is full without sounding tight and punchy like a guitar speaker (a problem with many ported monitors), and they handle the kind of explosive sounds you're often forced to use with video productions special effects. They're also great for in-studio monitoring of instruments. Got a POD or V-Amp you like to record your guitar with? These are a great choice for monitoring guitar sims and the like. (Something you would never want to use hi-fi speakers for because they aren't built with high SPL [Sound Pressure Level] ratings in mind among other things). This is my first venture into "powered" monitors. These RKOs are actually a bit large to call near-field since they carry 6" woofers and a front bass port, and you may find yourself wanting to test mixes on a smaller set, and I do test video sound on a TV with its tiny built-in speaker just to make sure there's nothing overpowering, but so far I can safely say that these KRKs have been terrific in every way.
One more thing; you'll notice that these KRKs have a bottom slotted bass port. I've found over the years that there's just something more satisfying, and less fatiguing, about having a slotted bottom port rather than the small round hole that's generally placed above the woofers on most ported speakers. I can't tell you why they sound more natural, but suffice to say that they don't have that artificiality that round bass ports have, at least not to me.
If you're only going to have one set of monitors in your studio (many people have several sets of various sizes) then I would say that you'll want to stay with something in the 4 to 6" category woofer size. You could do a lot worse than these KRKs.