are Pro Sound subbies any good?

theyre crap man. Not worth the money. A decently set up set of 6x9s like a decent brand will sound better. + Sony subs and boxes can be bought 4 less that 200. I know sony arnt the greatest but theyre better than prosound.

so what would a 10 inch be worth? i am only after a real cheapy.

Mate i have a Power Accoustic one which is better than Pro Sound... Ya can have it for $20 if ya want.

depends what sort of system u r looking at, if your looking at running a sub of your head unit, well it aint gonna really make a difference if u have 6x9s. If u are considering buying an amp a decent sub will be much better. a 10inch explod sub is about $99 bucks. I think a 12inch would be around $129. + about $70 4 a premade box ( u need one). or about 35 to make your own. To run say a 10inch explod sub ud be looking at least getting a fair amp to run it. A sony 222 amp is about 199. so roughly about $350. A lot of dosh i know, but this is what u need to spend to at least get a fair system.

sorry but how do you run a sub just off the head unit?

I wouldn't even bother mate, you're wasting your time if u do that

but how do you?

With pioneers they have something called FIE. Front imiage enhanser. The two rear channels only put out bass when this mode is selected. Brige these to rear channels( put together ) and run these to the sub. Or use a cross over. A cross over breaks up the signal from a full range sound into just bass or just trebble . U need one of these, shouldnt be too much 4 a cheapy maybe 20-30 bucks.

Yeah you might as not bother running it off the headunit at all it'll sound crap for starters and you will only be able to connect up one channel. Get even a cheap amp (for like $150) and it will be 10x better try and get one with a built in x-over. Some original photos have not been recovered yet.