coaxials, components, what do they mean and WHICH ARE BETTER!?

[Stealth]

OK i've got a question regarding speakers... there seem to be so many names for the categories of speakers... so i'd like to get straight exactly what each mean...

there's "components", which as far as i know the definition is the round speakers... the 5.5", the 6.5", etc.

then what do you call the 6x9s, 4x6s, etc.? coaxials?

Also, apparently component speakers are better, right? because almost everyone i've met recommends instead of putting 6x9s in the stock 6x9 hole in the back deck of my car, to get a 6x9" to 6.5" adaptor and put 6.5" components in... why's that? if the 6x9s have as big cone area, and some of them have two tweeters inside too, why not just put the 6x9s? i'm confused in this area, and since i'm paying for and getting my mids/highs installed tomorrow, if there's a last minute thing i should know about this, i'd like to know as soon as possible ;)

Thanks

[trungthiendo]

coaxials...tweeter and mid driver on the same axis...

components, each individual and you can place where you like

[helotaxi]

Component sets are generally made with better drivers, have an external filter network and cost more. The downside is that they are more difficult to install because you have to worry about mounting the tweeter and the crossover somewhere. There are coaxial speakers that are made with the same drivers as components by the same company and are of very high quality and even include external crossovers, but these are the exception rather than the rule.

[trungthiendo]

i have a pair of coaxials...Polk/Momo mmc650 to be exact. They came with external crossovers and they sound pretty decent. Mind you i am only running off the HU for the time being. 45x4 watts max, so i am probably only seeing 10-15 rms watts.

i bought them for 90 brand new, because i knew someone working at circuit city and had discounts.

i would recommend these if you could get them for the same price as i did...as i said they sound pretty good just running off HU, but i'm getting an amp so i will not be running off HU for long