alright so im setting up a system for my cousin to get as a christmas present and the budget is $500, i have a Stereo and speakers picked out but they dont want to buy an amp so my question is will the stereo be able to power these speakers. the stereo is an Alpine CDA-105 and the speakers are the Alpine SPS-600c and SPS-600.

these speakers

http://www.crutchfield.ca/Alpine_SPS_600C_6_1_2_6_3_4_2_way_Component_Syst_p/500SPS600C.htm

well for starters these are comp speakers and to get full performance out of them i would highly recommend you buy an amp and some sound deadener!

and these

http://www.crutchfield.ca/Alpine_SPS_600_6_1_2_6_3_4_2_way_Car_Speakers_p/500SPS600.htm

are coaxial speaker and they will sound bad at higher volume setttings if you run them off your h/u but no amp for these speakers is do-able

Do you have to use an amp?

No, it's not required. But if nothing else, I'd try to talk them into atleast a small 50w x 2 amp for the comps, that or save some money and go with coaxials for all 4 speakers instead.

For example, here is a US Acoustics on ebay for $25+shipping. I've not dealt with that seller before, but he's been selling refurb'd US Acoustics on ebay for years.

they decided to get just the stereo because they said the speakers are decent its just they have a super shitty stereo, it plays cassette tapes, thats how old it is, they just want ipod control.

so they are getting the coaxial speakers then? and not the comps? b/c comps will need the amp and some sound deadener to really really shine over normal coaxial speakers. comps are more of an investment! but so much more worth it in the end!

Don't be confused, the coaxials will benefit just as much as the component from proper deadening, amplification, and signal modification (EQ/Crossover). Also, coaxials can many times be a better alternative than components.