Good idea Francois! Maybe low freq response could be a bit down with these small/cheap speakers, but reflectivity problems will be greatly solved.

Actually, a single sub with one of the sets would probably turn the trick. Distributive is better, but does occupy more space and could be a cabling mess.
We did an event recently in Sydney, where industrial Velcro was used to hold extremely small speakers on microphone stands with a bit of heavy cardboard attached to it. Worked quite well.

this is usually working well in place like museum ,church or other high reflective and silent room.
The only problem is that you can not usually keep up with a noisy and compact crowd because power is not available.
For the bass, you could be surprised by the ability of these small boxes to generate earthquake rumble (don't forget , they are designed for game).
My preference goes to the Logitech Z-640, others models usually have a too metallic sound.

let's see if i understand what you're saying. about the multiple speakers at low power... do you mean that if i hook up an additional pair of cheap PC speakers to the receiver in addition to my pair of 100W pioneer speakers, i could improve the sound?

by the way, the receiver has a 5.1 speaker system. how exactly do i connect PC speakers to that?

adi.

I do not know what you mean by 100W loudspeaker, but if it is real professional equipment rated 100W RMS, this is huge the room you described.
The proposal of having multiple low power loudspeaker includes the fact that you are not using the 100W installation system (or set it up to play very low).
5.1 pc system have the big disadvantage that few of them comes with other input than 3 minijack well suited for pc output, less for other 5.1 devices like DVD players (usually coax or optical).

<<<-- Originally posted by Giroud Francois : I do not know what you mean by 100W loudspeaker, but if it is real professional equipment rated 100W RMS, this is huge the room you described.
-->>>

Pardon? Not hardly. Wattage and volume are not necessarily related at all. More wattage in the amplifier simply means more headroom so that the system may operate more efficiently. Particularly computer speakers, which have horrible efficiency ratings anyway.
Moreover, you're not likely going to find a system that would fall into the "professional" category that's only 100 watts RMS.

Regarding the 5.1 speakers, I'd forget about the center and rear speaks, and rather use "Y" cables to feed additional systems. You don't have to worry much about impedance mismatches because you're not loading down an amplifier, although your more lengthy runs will induce noise into the system. Quality of cable and presence of noise-generating sources will determine just how much noise.
The best way to manage this at all is to set it up in your living room beforehand, work with the cables, and find out more for yourself. While many folks here in the forum have various experiences with this sort of scenario, it's also likely that you're going to end up still figuring your specific need out on your own, and since none of us are there, you need to know what you've got before you get there.

ok douglas. could you please just explain what Y cables are?