I must have been lucky up untill now with the audio stuff in my car.

Just put a Pioneer DEH-2050MPG headunit and a pair of Clarion SRR6986 6X9 2 ways into my girlfriends corolla (KE70)

Problem is that at higher volume levels (over half) it gets really crackly on the beat of the music. songs with lots of bass (chemical brothers) Dont do it at all, but music with both treble and bass (rogue traders rihanna) crackle like mad.

ive tried:

Disconnecting the factory front 4" speakers - No Dice
adjusting treble/base on the HU - No dice
Powering directly from a battery - No dice

now, i did find a black with yellow trace wire form the old HU and connected it to the mounting post on the back of the new one - this did improve things slightly but not much.

any sugesstions would be greatly appreciated

umm obviously the speakers can't handle it

sounds like your pushing the h/u to hard and its "clipping" the speakers especially with 6x9's.

an amp will fix this

crap - how come the 6X9's dont do it in my car then? or is it just cos my HU was a really expensive one (way back when i got it)

for one 6x9's are crap. distort wayyyyy to easily

FIXED - i went and had a looksee at the balance/fade/bass/treble on my HU - turns out i needed to adjust the fade to the rear speakers, goes all the way to 60 now without "clipping" (new word of the week for me ) thanks nannas_ed your post set my off on the right path