Most of the basics has been covered nicely above, so Ill jus reitterate (sp?) 6x9s are shit, and anyone who tells you different is a ool and has no idea about car audio, and is TRYING to make their system sound shit. It isnt actually the speakers which are THAT bad, its the placement. The parcel shelf is NOT a good place for a set of speakers. If you could use 6x9s in your doors, which some cars can, it would be worth considering a decent set. But usually 99% of the time, some components will be much better. What car are you planning on putting the shizzle into? If you like rock, your going to be wanting to put your money into your head unit and front speakers. Rock is much harder to recreate than say dance music. And needs a good set of components to seperate all the instruments properly. Your first port of call should be a decent head unit. I have a Pioneer DEH P77MP which is a VERY nice head unit and im rather please with it. Subtle looks with no lashig lighs or any of that poo and a very nice sound. I got mine new off ebay for £200 posted, but they often go for about £140 2nd hand. You could do much worse! Front comps should ideally have the biggest mid driver you can fit in your car (this is the speaker looking part of the components) and will also have a tweeter, which is a small maybe 1in round speaker which plays the high frequencies ie. the voices etc. I have a set of 13cm Infinity reference components and while I would like the next size up (biggest mids I can fit with adapters and no modifying of doors) they are very nice, cost me £100 new but can be had for about £60 2nd hand. You should Ideally amp these front speakers to get the best from them, and would be amazed at how much better it sounds once amped. And old skool alpine amp can be had on ebay for under £30. I have a 4 channel alpine jobbie which my girlfriend bought me and Ive bridged the 4 channels into 2 channels giving my 75w comps 100w. This is more than enough let me tell you! All this talk of 350w this and 200w that is usually absolute shit and should be ignored. As for a sub, I have a old 12in kenwood sub, i mean were talking 12 years old in a proper beasty ported box with a old skool kenwood amp to match. Wouldnt believe how good it sounds to look at it lol. The old stuff is the best! Also, as with all audio home or car, 2nd hand stuff is just as good as long as its from a reputable source and its cheaper!