I have a jbl GTO 1201.1 powering 2 12" L7's and a alpine 340 for my mids and highs. I have the subs in a 5.0 ported box. I have a 2000 impala (3.8 version). Right now my lights dim like crazy and my idle drops dramatically when my bass hits. A car installation shop told me I need another battery in the trunk. This dosen't seem like it concors with everyone on here. Currently, I have a 105 amp stock alternator.
My question is first do I need a new alternator and second if I do will 160 amp be enough. I found one online for $169.00 plus 18 buck shipping. Do I need this?