All started when my tweeter broke, i got my working one and starting unplugging it and plugging it in while my music was playing, realised it was defiantly broke and exchanged just the tweeter for a new one. Put it all back together and i noticed that my speakers made a horrible noise when the gain was turned up and there was a wine when the engine was on from the woofers AND the tweeters, but it was a fixed noise and did not correspond to the rpm's. Tried some 6x9's on my amp and there's no problem at all, so it wernt the amp its my speakers. So i tried to take them back at one shop and the geza was checking the woofers and were saying they were fine. He told me that i must of been overloading them because they are 3.6ohm and my amp is 4ohm but my amp is stable at anything down to 2ohm. And he was saying you have to get them to match, but i don't know any amp that is just 3.6ohm. So i walked out and had to exchange them at another halfords. Just about to go fit them now and hopefully the noise should be gone as i narrowed it down and it was defiantly my old set of speakers.