guys, i recently installed a sub and used an ignition feed from the back of the stereo to connect with the remote wire. all was fine until....i switched the engine on and now i have a pulsing sound from the sub? should i use a different ignition feed or get one directly from the battery and use a switch (so the amp isnt all 24/7?)

[color=#0000ff][size=5][font=comic sans ms,cursive]I would install a separate fused feed from the battery and switched by a relay controlled from the ignition.[/font][/size][/color]