On axis means are they pointed at your ears. Off axis means they are not ex: pointing across the car, pointed at the windshield, etc... On axis can sometimes sound harsh depending on the tweeter.

Test the tweeters out with a CD... it could be your source of music. My MP3's never sound as good as a CD.

 

well that set of JBLs is rather aggressive in the HF especially compared to JL. But if the JL was also edgy... then the common thread is your car (lets assume it ISNT equipment for a moment). Is one ear more aggravated than the other?

I don't suppose the tweeters are reflecting off some hard plastic or glass surface? If so take a towel and lay it around the tweeter area (it will absorb some reflections if that is the issue).

If it is loud all the time it is generally one (or two) issues, if it is only loud at certain frequencies it is generally another.

 

any particular tracks that seem more harsh than others?

 

On axis, As in pointing towards the driver.

 

All the music is bad there aren't any songs that are good. The tweeters are pointing to the center of the car but not at much of an angle almost straight at eachother

 

i assume you've tried changing the angle, adjusting tweeter level, etc.. by now. I would try hooking up a different amp, or running the comps off the head unit's amp to compare. You mentioned the same issue with a set of JL silks, so that's telling me that it's not the components. Check the amp gains(make sure they are not cranked (this could introduce excess noise and may be causing the tweeter distortion), and if any eq or other processing is turned on in the deck or on the amp, as these could cause distortion.

 

turn down 6k and 8k and the sibliance you are hearing will be gone,.its a start..

 

I agree, notch out 8k should help. start with -3db or so. usually minimum correction is best.