Having owned & auditioned my Motion Sound KP-100S:
http://www.motion-sound.com/keypro_amplifiers.htm for a week now, which includes utilizing it on several gigs, I think I've finally found the idea compact lightweight self powered all in one stereo PA speaker system suitable for those small- medium gigs.
Before the new Motion Sound stereo Key Pro series speakers became available this year, if you wanted impressive stereo sound, you'd have to drag along two speakers. Many current keyboard sounds rely hevily on stereo effects to show them off to full effect. Unfortunately, simply mixing the right and left channels together to a single mono output produces stereo 'phase cancellation', which results in inferior (thin) sound. I found the 'LIVE Grand' acoustic piano and several other essential voices on both my Yamaha Tyros & PSR2000 to suffer from this when going out mono.
I had initially considered getting the larger KP-200S, but at 55 lbs, it was out of the question. I wanted a lightweight 'small as possible' unit to insure both quick & EZ setup/breakdown. I opted for (with a bit of initial reluctance) the substantially lighter (38 lb) and more compact KP-100S instead, though it's only got an 8" woofer and 100 Watt amp output, vs a 10" woofer and 200 watt output on the KP-200S.
When the KP-100S arrived at my door, I was surprised just how small & compact it was, though it did seem a bit heavy 'for its size'. When I initially tested it out, I placed it up on a chair behind me, and though the sound was clean & clear, and produced plenty of volume to spare, it sounded a bit harsh in the mid range, and weak (missing) in the low bass frequencies. Raising the bass EQ knob didn't really solve the problem. After re-positioning the unit , placing it on a small amp stand: Ultimiate Support model - Genesis Amp150:
http://www.ultimatesupport.com/genesis_amp.html , with the KP-100S angled up at approx. 38 degrees, the sound improved dramatically, eliminating the harsh mid range and improving the bass response signifcantly. Adding the Yamaha Tyros' subwoofer unit to the mix improves the sound even MORE, filling out the frequency range with an impressive bottom end. The enhancer really opens up (spreads) the sound eliminating the impression that the music is coming from a box and some people in the audience have even commented that it appears that different instruments (piano, drums, bass, horns, etc) appear to be coming from different spots in the room rather than from the KP-100S itself. I'm also happy to report that the enhancer does not appear to detrimentally affect my vocals when set to the normal (not to high) position.
For my nursing home & smaller venues (less than 35-40 people), I only need to take the KP-100S along with 27 lb Yamaha Tyros (no Tyros subwoofer or satellites), and it provides very pleasing results. This configuration is especially suitable for acoustic sets with vocals highlighted by acoustic piano comping/playing along with auto accomp bass & drums. According to John Fisher (Motion Sound), the KP-100S & KP-200S were specifically designed to reproduce the acoustic piano and I think this is a success. For a deeper fuller bottom-end electric bass and overall richer sound, I can easily plug my small Tyros subwoofer (17 lb) into the Tyros. Is now no longer essential for me to utilize the Tyros satellites anymore now, because with the KP-100S, I'm able to successfully monitor the KP-100S mix while playing the KB. My Tyros subwoofer is also easy to transport now because I installed a convenient carrying handle on top & 4 rubber feet on the bottom.
Transporting & setting up now takes no longer than my simple PSR2000 setup did. For larger venues, I continue to utilize (and recommend) a pair of Electro Voice SxA100's. I'm now a very happy camper. I highly recommend both the Motion Sound KP-100S and (of course) the Yamaha Tyros.
Both DanO and the folks at Motion Sound (John & Aloni Fisher) provide excellent sales & customer support. Many thanks to them for arranging the KP-100S to be drop shipped to my door. If you're interested in the Motion Sound KP-100S, I recommend getting it from Dan O'Neil.
His email address is keyboardcity@yahoo.com.
Scott