distortion at higher volumes

i replaced my factory HU with a Sony GTX-340 and replaced the factory speakers with a pair of Phoenix Gold RSd690 in the rear and RSd5 in the front...the rears are rated at 80rms and the fronts i think are 50rms. At higher volume like 35 and up it starts to sound not so good. i have several theories....1 is their just cheap speakers ($40 for the fronts and $60 for the rear 6x9's)....2nd is the cds i've been playing are burnt songs from limewire and being they are compressed files is why it sounds like doo doo or my 3rd theory is these speakers need amped. I really dont think its the speaks cuz i mean they ARE pretty nice...solid construction...big magnet and they sound REALLY good until i jack the volume up. I can almost guarantee its not the wiring cuz i mean i work with wiring everyday so im confident its not that. Any suggestions?

Volume number has nothing to do with it really..

I've had people return radios to buy BOSS radios cause the number goes to 100.. all that is is a representation of fully closed to fully open.

now in your case.. you are turning your radio to roughly 3/4 or higher and i'm willing to bet if you want more.. you might want to consider an alternate power source, 4 channel amp or the likes.

Decks aren't exactly known for their clean power.

cool man i was hoping someone might say they need amped...i just need to find a decent amp for under $100 because i aint droppin a lot of coin on this system. im not trying to go junk either if ya know what i mean.

Were the factory speakers 8, 4 or 2 ohm? 

A lot of people will buy speakers with high power handling, yet overlook the more important Sensitivity spec, which could be your issue. I agree that an amp would help a great deal, but if you have speakers with high sensitivity, you don't need to turn your head unit's volume up so high to get good sound. Just make sure you get speakers with higher sensitivity specs and a broad frequency response, and make sure your amp's wattage output is MORE than your speakers' max input. You'll instantly notice your distortion is gone if you set everything up right. A huge number of folks will buy an amp with say, 100wpc then buy speakers that handle 200wpc (for example), then wonder why they get so much distortion. A knowledgeable local stereo dealer might explain the theory behind this, but many won't. Good luck!

^ thanks that was informative.

i am an idiot wrote: Were the factory speakers 8, 4 or 2 ohm?

rear 6x9 were 8ohm and front were 4ohm...the new ones though are all 4 ohms. it's almost comical the difference in size of magnets from factory to the speaks i have now...AT LEAST 5 times bigger...lol!

Don't pay attention to magnet size.

neodynium for instance.. =)