1000w to me definetly sounds like a 4channel. And if strathfield did it then it's all wired up to the amp.
Basically it sounds unclear because you have sh*t brands filling your car. Sorry but that's the truth.
Sony is probably the biggest player in the "fully sick" doof doof market. If you get into car audio you'll soon learn that products like this are aimed at SPL (sound pressure level, ie. loudness) rather then SQL (sound quality level, ie. goodness

).
Now if your serious about getting some decent components (you don't have to spend a mint, but you do get what you pay for) then follow these steps:
1. New headunit if possible but this isn't totally necessary
2. New sub, 10", dual if you must (2 subs) for punchier, tighter bass
3. Monoblock to run the sub (1 channel sub amp) if you have the money
4. a: 4channel hi/lo pass amp - run front and rear speakers
b: if you didn't follow 3, then 4channel amp and run the front speakers + the sub *bridged*, you can run the rear off the headunit
5. New front 6 1/2" splits (or full components but this is expensive)
6. New rear speakers, you want round 6 1/2" *rear fill* speakers because you don't really need the added bass of 6x9's when you got a sub
Brands to look at include JL Audio, Boston Acoustic, JBL, Blaupunkt and MB Quart. If you can find somewhere to ship from then you'll get yourself a *very* good deal.
To fix this on a very tight budget then reach into your boot, extract the subwoofer and throw it onto the driveway. Then pull out the front speakers and replace them with some quality splits.
Sorry if this seems a little harsh but if your gonna spend money on an audio system i want you to do it right
