I got a 1960 Oldsmobile 98. I had a problem where a loose wired touched my metal dash and fried some wires. After I replaced the wires and the speakers never got over 30 volume w/o crackling. I thought it was the speakers so I replaced them. The speakers can make it to 40volume and then start crackling. So my question is Is it my radio? does it need to have a bigger voltage output? If so what kind should i get? I checked the wires up and down and found nothing loose.