hey guys, i just installed a head unit into my car and am having some trouble..
the previous owner has installed some cadence speakers all round (speaker with built in tweeter kinda thing, sorry dont know what they're called)

what happens is, as soon as i turn my volume up over a certain level the speakers cut out, and for them to work again i have to turn the ignition off and restart the car.
ive checked over all my wiring, and nothing is touching. everything is soldered and heat shrink wrapped.

the head unit is nothing ancient, so i dont think that it is the problem..
im not running an amp, and i dont plan to as ive had a similar setup (just normal speakers though) work fine on my previous car

what could it be? its driving me insane!!!