The other day my speakers all of a sudden went crazy, really loud static but the music still playing, then music stopped and a REALLY LOUD, REALLY HIGH continuous frequency played until i turned the HU off. Now over the past few days it's just been inconsistent loud static (louder than the music playing), this happens when either my ipod or cd are playing, radio too i guess. Now the static mainly comes in when i hit a bump of the front passenger door gets opened or when window going up/down. It's unbearable, so i've been tune-less :(
Haven't had the chance to have a look, loose connection maybe?
Will pull it apart and have a look tomorrow night, any thoughts other than just a loose connection?

Thanks.

seems like it may be engine noise
try re-routing your RCA's, making sure they are well away from any wires

It wont be engine noise.

Really loud continuous frequency, last time this happened to me, a speaker was shorting out.

In your case, its unlikely that every speaker has shorted, survived, and there's a continuous tone.

I'de be looking at RCA jacks at the back of the headunit, the RCA fuse.

Secondly, IF this is the issue, I'de be finding out why the RCA circuit has blown.

NINJA EDIT:

First question should actually be, are you running amps off the H/U?

Then, should have mentioned to check the RCA connections on the amp and the H/U, and to then check the RCA circuit on the H/U.

My bad, its late and yeah.

I actually had something similar to this happen the other night when doing some work behind the dash, fired up the head unit without the rca's plugged in (clever, I know) and had a noise similar to what you're describing come blaring out of the system. Turns out while the leads were unplugged, they were sitting pretty well in top of the power feed to my h/u and picking up mass amounts of interference from the electrical system with nothing to overpower it, so was given free reign to just screech its head off. Plugged them back in and moved leads and problem was sorted. Also, as mentioned earlier with regards to bumps and door opening and closing, might have a break in speaker wire insulation somewhere that might be grounding out, picking up noise from chassis. Could be worth investigation wiring in suspect door to make sure nothing's grounding out.

Thanks ers, will check all of them.
My amps are running off the HU, rca's and speaker wire are on opposite side of the car to power.
Hopefully it is something simple like a loose RCA or something.

With some luck its just a loose RCA connection.

Re-read your post a little more aswell (due to Bluey's reply)

One other thing to check before you rip out the H/U to check the RCA's. Is the noise just from the front passenger speaker?

If so, Bluey is probably closer to the mark than I am, if its just a loud static noise from front left speaker, check the wiring of that speaker prior to ripping your dash apart.

Reason why its not engine noise (IMO):

Noise is constant (and I assume increases with volume going up?)
Noise is not getting louder when engine rpm increases.

I'm 90% certain that it's coming from both speakers, can't really tell when it's blasting in my ears.
And it also doesn't sound like engine noise at all.
Will take bluey's post into consideration as well when i attack my interior tomorrow night :)
Will hopefully post up with the problem :)

Thanks guys!

check your amp earths as well

Just took the front passenger door panel and speaker off, checked the xover connections, tugged on the speaker wire and it came out, so i re-did it, put everything back together and it's working fine :)
Not sure if that was the problem or not, but i hope the problem doesn't come back.