1) no subwoofer
2) same as 1
3) if it's anything like the older C3 that i have, lacking a lot of mid bass/mids
4) lacking everything however still considered good for the pricing it is demanding. bought this for my sisters and they love it
(too small subwoofer/mid or mid bass speakers)

so may i suggest S530D instead bro.

i just gotten this, bass not as "rattling" as my Creative G500 THX certified, however to make up for its lack of quantity it has plentiful of quality bass where you can be easily moved by it

pricing is very reasonable for what it offers

for connectivity, try to just directly connect first.
if insufficient only consider DAC (which i doubt you'll need)

I guess I should say some words since I've tested both Studio 8 and S530D in my room

It's either you get the Studio 8 or opt for Edifier S530D (you can ignore your other options)

S530D will give a harder kicking bass compared to Studio 8 mellow bass

Both pounds hard
Both gives clarity

In any case you need rock, these 2 are just not meant for it due to its massive sizes contributing to sluggy speed while rock needs things fast. (however your 2nd option R2730DB can do it)

but hey, they're both superb speakers to invest in so I'd definitely recommend choosing either one.

I'd go for Studio 8 if you got the table space mainly because it sounded more 'huge' compared to S530D (plus the amp could save you some electric bills)

I own the S530D and technology wise it's outdated. But sound wise I'll always go back to the S530D when compared to Studio 8 because it has more warmth over Studio 8 cold feel

Hope it helps in your decision
If you can't decide... Just buy based on looks
That's what I do most of the time nowadays. Cosmetics>Sound
I should be punished someday

During purchase most probably the area is noisy so you can't notice the noises produce from the speaker.

Did the noise still there when the speaker volume is at the lowest? And does it reduce when you connect to audio source?

Looks like the amplifier amplifying the noises because of the volume was turned too high on idle.

Try use different power socket, if still persist, go for warranty. Btw, can I know where you bought your Studio 8? I'm planning to get R2730db soon, just wished to know  .

I have not heard noise/static noise during my audition with the Edifier Studio speakers in Lowyat.
Try changing to different modes (Coaxial, Line 1, Line 2, Optical) and see if the issue persist in all of them.
Try setting the treble and bass at 0dB and volume at 25 (which is 50%) and try again.
Try placing it in a different room and turn it on there. Maybe one area has too much static energy?
If error still persist, can give Edifier a call to make arrangement on sending the speaker for warranty at their HQ Sunway Damansara.