How to tell if you need brand new speaker wire?

1)Examine your speaker wires really carefully were there is lot of light and look for any green color inside the casing inside the wire.The green stuff is copper oxide which causes corrosion to the copper wire which is know as corroded copper wire.You can try to cut off with a scissors or wire cutter were the cable has gone bad and still use the good bit of the speaker wire.

2)If you are also using more rms power from a external amplifier rather from a car head unit to power your car speakers with the stock wiring that comes with the car then the Speaker's can loose loudness and sound quality because the speakers receive less input signal from the stock speaker cable.To tell if you need new speaker wire to replace the stock wiring you have to look very close at copper inside the wire.Does it look black and a little burned? If yes is the answer its need replacing because the stock wiring can't handle loads of rms power from a car amp.And just a little tip when buying speaker wire make sure you know how much gauge the wire needs to be.