you're buying klipsch
i just helped a friend to get last 2 month, now very hard to buy.
btw your CS21 i open up & changed the subwoofer cable
original cable is.. hard to believe it can drive the sub

Since it's just for temporary used, go grab a 2nd hand Altec Lansing VS4121 will do until you've enuf budget for the Edifier S730D    No nid waste money getting new Klipsch GMX 2.1

@Narkon

let's settle the problem between ktek and the CS21.

i really hope u read my reply promptly. i did said, get the Z5500 first, and then decide which part you want the soundcard to improve. anyway u can buy first, but in the end you may regret if it doesnt suit you. as i said previously, asus and creative have different personality. some ppl like asus, some like creative. u cannot just say this one better than other, because sound is subjective. just like food. some prefer rice others prefer noodles.

as for the cable, it improves performance, but since Z5500 is just a computer speaker,
the difference would not be much. so dont upgrade the cables.

if u cannot listen to them, reads reviews in google. if you dont understand terms like boomy bass, tight bass, recessed mid or etc, ask here.
by reading those reviews properly (u should cause u are really concerned), u have idea how it sound. at the very least, if u dont want reviews u just tell us what are your characteristic and expectation of a speaker u gonna buy.

let me give an example, my own experience:
- i like to listen to techno and electronic songs, i prefer great bass than superb clarity. -> basshead
- i like to have a speaker, that has good bass that when i play even at low volume, i can feel the heartbeat -> find spk with deep bass
- my room is super small -> dont find a speaker thats too big. my ifi is too big in my room.
- when watching movie, i want to feel the ambience of the movie, make my room sounds large -> get a room-filling speaker.

if, u give details like my examples on what u like and what u dont, trust me, more forumer can suggest u to which one to buy, without being afraid u get the wrong one.

if i like to listen to techno and electronic songs, i prefer great bass than superb clarity , then what speaker better ??

yeah maybe u should consider again.. im not sure how loud zcinema can go, but i think it should be average?
its 8inch sub btw.
say no to VS4121 and logi Z4.

U cant really compare like tat because Z-surround is a 3D surround speaker. Even the Edifier wish to do 3D it cant because its not design to. 2 speaker = capable to create 3D surround