How to turn on you Sub woofer control on your Pioneer DEH radio - YouTube
How To - Subwoofer Settings - on Pioneer AVH-290BT, AVH-291BT, MVH-AV290BT, AVH-190DVD - YouTube
What are the frequency settings for a subwoofer? I have a subwoofer with 4 different frequency settings. I need powerful, punchy bass. Should the setting be positive or negative? - Quora