I didn't purchase any of above two but had chance to listen to them just wanted to share my impressions :)
lets start
Harman Kardon SoundSticks III
LOOKS
Just by first look on them WOW!!! I don't know if this happened with all of you or not. When I saw them on web thought they would be bigger not sure why but they qre quite small. And the transparant design works very well. clever design decisions like upward-angling, adjustable speakers. cable quality is improved from SoundSticks ii.
SOUND
After listening to them I would say they excellent audi performance. The subwoofer looks compact but strong enough to generate superb bass to fill a room. The tweeters they also deliver excellent sound.
started with some reggage songs bob marley buffalo soldier
linkin park - waiting for the end ( Bass was awesome )
Julai - O madhu
There's nothing really new here to discuss—I'm pretty certain we are looking at the same drivers (four in each satellite) and same subwoofer that we saw in the previous model. If you are unfamiliar, however, the SoundSticks series offers more than just looks. Like most quality 2.1 speaker systems, the sub comes equipped with a volume knob to boost or dial back the bass response, and like most subs, it performs most naturally with the volume set just at, or a little below, the halfway point. While the placement of the knob annoys me, the argument can easily be made that this is a setting you adjust once or twice and then probably never again, so it's a tolerable annoyance. At this setting, not even the Knife's "Silent Shout" (a bass-heavy song that often humbles modest subwoofers) distorts at maximum volume. Boost the sub to max, and yes, distortion artifacts appear, but this is not really the way music should be listened to—the low end, when at maximum volume, is far too intense to offer a balanced mix. Perhaps some listeners will like a heavier subwoofer setting for movies, but whether you're listening to classical, acoustic, rock, rap, or jazz, the SoundSticks III, with the sub set at reasonable levels, offers a splendidly crisp audio experience with generous, well-defined low-end.
Cons:
No remote.
Logitech Z623
LOOKS
Not that bad looking system. subwoofer is pretty big. spekers normal looking nothing special. The right speaker's front panel houses three knobs—for Power, Volume, and Bass level—under the 2.5-inch driver. Two 3.5mm connections—an auxiliary input and a headphone jack—sit on the right panel of the speaker. Its THX certified so could attract movie fans. Hard wired cables.
The subwoofer is huge, in every sense of the word. The behemoth measures 11.9 by 11.1 by 10.4 inches (HWD), and its output could rattle the paint off your walls. Luckily the bass knob, conveniently placed on the right speaker and not on the back of the sub like systems from some manufacturers
SOUND
Reasonably priced. Excellent audio performance. Extremely powerful output. Subwoofer level is easily adjustable. THX certification.
The Z623, simply put, sounds awesome. Film scores from Bernard Hermann sound crisp and foreboding, with deep lows from the strings beautifully represented by the sub and the satellite drivers. Music with deeper bass, like the Knife's "Silent Shout," sounds closer to what the musicians had in mind—powerful-but-well-defined low end—than most 2.1 systems under $200 can deliver. When you blast the system and turn the bass all the way up, you won't hear any distortion—but, again, you'll want to secure fragile items nearby. With each satellite delivering 35 watts and the sub pumping out 130, the Z623 is definitely loud enough for your next party. At moderate and even low levels, it conveys music and dialogue beautifully. Turning the bass knob to maximum (or close to it) with the volume way down accomplishes what "loud" buttons on older stereo receivers used to—you still hear the bass even when the system is operating at quiet levels.
Cons
no remote
hard-wired cables
sound could be little brighter
Over all : I like soundsticks more than Z623 because of design and sound.
If you want loud enough for the price you could get Z623.
