Quote:
Originally Posted by Latamfan
Hello, please tell me what is your opinion in order to upgrade the standard audio system for a bmw m240i coupe, knowing that I was triying the amplfier JL JX400 and always heard a noise through the subwoofer, reason why I decided to uninstall this.
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What you're describing is classic radio frequency modulation, which is almost always caused by an improper ground. The problem wasn't your amplifier; it was how that amplifier was grounded.
Follow these guidelines:
- ALWAYS make the ground as short of a run as possible: ideally no more than 1 foot (.3 meter).
- ALWAYS ground to bare, untreated metal. Primer or anti-rust coating isn't bare metal; you'll need to grind or sand this off.
- ALWAYS use a ground that is part of the car's chassis, not something bolted to the car's chassis. For instance, seat-rail bolts are a common choice to attach a ground to when an amp is mounted under a seat. It's actually a mistake to do this because the metal in the bolt and the rail is often not the same as the chassis and is often coated or painted.
- ALWAYS use zinc or copper hardware to fasten a ground. Stainless steel and nickel are not nearly as conductive and can create problems.
- ALWAYS attach the grounding wire straight to the untreated metal. Washers and bolt/nut heads should be above the wire (and/or whatever fastener that's spliced onto the wire, such as a spade or ring.)
- NEVER share an amplifier ground with another component.
Hope this helps.