Hi bigbird2323,
Apart from the brand you mentioned there are others like Xenon, Kingfisher, Akira, Orange, Promac, etc. These are China-made products from companies that also produce or market generic DVD players. They are unabashedly advertised with totals of 700 watts to 3000 watts PMPO and are priced from P1,500 to P4,500 tops. I believe their true power output for all channels ranges from 15 to 80 watts total in RMS using 3.2 to 4 ohm speaker loads. Check the back on the main sub unit for power consumption. A typical sub-sat's 50-70 watt electric power consumption cannot give out more than that in acousitc power Check out the user guide before getting one. Distortion figures in THD are high at about 1%. So they may only be of audiophile grade at about half the rated power or even less.
I don't have first hand experience with the brand Rongxin. But if it is anywhere near the other brands, let me just share my experience with the Kingfischer 5.1 sub-sat system
In my early HT days, listenning to AC3(DD)and DTS required a dedicated rear and center channel input that my DPL recvr did not have. I had to buy in the interim a Kingfisher powered sub-sat for the rear just to test out, in my eagerness, the much touted discrete stereo rear channels (it was cheap at about P1,200) and 2 mos later upgraded to a P4400 Altec Lansing (a tad better but still below audiophile grade) So what did I discover?
I initially connected the Kingfisher sub-sat (which came with 5 sats and 1 sub) directly to the 5.1 analog rear channels of my new DVD Player (using only the sub and 2 sats). At first, they sounded adequate for the rear ambient sounds in some DVD titles (The Patriot, The Mummy,) but even with the sub firing away, it was thin and certainly inadequate to reproduce more power hungry DTS rear sounds. The clipping was outragiously audible for transient bursts in DTS mode (Pearl Harbor, Atlantis, Titan A.E.) and even the dinosaur sounds in Jurassic Park in DD only.
Out of curiosity, I tested the Kingfisher in all 5s connected directly to my DVD as main speakers. For sure, they couldn't shake my room (4m by 5m). The low frequency distortion may not be audible for most DVD/CD titles but the sub tended to sound the same across the low frequency spectrum I think that's what pundits call "one-note bass" to characterize subs that are inadequate.
As they are apparently copied from BOSE powered sub-sat systems, (which are thrashed in audiophile circles) the Kingfisher sounded bright and too forward for my taste. With 2" satellite speakers, they are hard to produce the lower-mid frequencies (250Hz to 700Hz) that make even those cheap 4" bookshelf speakers sound warmer and fuill-boided in comparson. And those subs crossover at about 250Hz with the amp apparently designed to bost frequencies in that region. The sound is similar to having an equalizer that have their sliders in a V formation. Patti Austin sounded shrill when it should be warm. Charlotte Church is simply unlistenable. But the bass thumps are quite boomy, undefined and room-filling (but not room-shaking)
The powered "subs" are just powered woofers and, using only 5" - 6"drivers on a small housing, they can only go as low as 80Hz and roll off steeply below. The Kingfisher user guide confirms this on their tech specs (I bought it just the same since it was meant for the rears only and rears are not suppose to have low bass, or so I thought, not in DTS) They may sound adequate on Disco/rap/rock music with a lot of thumping drums and electric bass lines in the 80hz area. But sorely wanting on jazz or classical music where the accoustic bass and church pipe organ can go really deep into the 20Hz region On movies, especially with transient explosions, the 6" woofer just bottoms out without even a boom, much less the visceral effect one experiences with the bigger subs. You can feel air movements out of the little hole on the sub, indicating the small woofer's large excursions trying hard to cough out the low frequencies, but with nothing coming out.
If you just want to experience 5.1 discrete DD/DTS channel separation on a very tight budget, these powered sub-sats may be the best option short of getting an HTiB which would put to waste your existing DVD player. One other thing with regards separation, they sound very speaker specific. That speaks well of the separation but because the sats are so small, too bright/forward and have very limited horizontal sound dispersion characteristic, you can pinpoint the sound as coming from this or that speaker. That means the surround effect is not as enveloping as it should as it doesn't blend well across the speakers in the room. The more expensive ones may even rattle the room a bit. Just don't expect it to sound like your neighbor's Yamaha-B&W-Velodyne or Onkyo-Wharfedale-Dynaquest set-ups
It should be obvious I am not disposed to favour these 5.1 sub sats. Not even the Altec Lansing which sounded a lot more detailed, fuller and with tigher bass than that of the Kingfisher. (I promptly disposed oof then once I got a decent Wharfedale 8.3 for the rear and a Rotel DD/DTS pre-pro. ) I hope the Rongxin brand is much better. You should audition it first, preferrably in comparison with a HT receiver+decent bookshelfs + sub. But if I know the vendors of these sub sats like in Coastal Mall, that would be asking a lot.
Hope this helps.
