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<blockquote data-quote="KaeZoo" data-source="post: 2467679" data-attributes="member: 554753">First of all, .2 ohms is not a good rating for a ground connection.&nbsp; You can calculate the voltage drop through a resistance using Ohm&#039;s Law, E=I*R.&nbsp;&nbsp; If you have a .2 ohm resistance, then running just 10 amperes of current through it will drop your voltage by 2 volts.&nbsp; &nbsp; To put it another way, if there&#039;s a point with .2 ohms resistance in the circuit, it&#039;s the same effect as running your power through 200 feet of 10 gauge wire.&nbsp; On the other hand, most DMMs aren&#039;t very accurate when measuring very low resistance values, so who knows what the real resistance is.Second, he was technically correct about the battery playing a major part in filtering noise from the electrical system, but recommending a capacitor to fix a noise problem is completely ridiculous.Using a walkman to provide a signal to the amplifier will automatically remove a ground loop, since the walkman doesn&#039;t share the same ground as the amplifier.&nbsp; So even if you get clear sound with the walkman as a source, it doesn&#039;t mean the head unit is the culprit.&nbsp; The way to eliminate the head unit is to substitute another known-good head unit, not a portable player.I&#039;d try re-grounding the amplifier to another point, and make sure you have a tight, paint-free ground connection.&nbsp; Double-check the head unit ground also.&nbsp; Check your battery connections and make sure they&#039;re tight and not corroded.&nbsp; Also check the connection between the chassis and the battery negative post.</blockquote>

[QUOTE="KaeZoo, post: 2467679, member: 554753"] First of all, .2 ohms is not a good rating for a ground connection. You can calculate the voltage drop through a resistance using Ohm's Law, E=I*R. If you have a .2 ohm resistance, then running just 10 amperes of current through it will drop your voltage by 2 volts. To put it another way, if there's a point with .2 ohms resistance in the circuit, it's the same effect as running your power through 200 feet of 10 gauge wire. On the other hand, most DMMs aren't very accurate when measuring very low resistance values, so who knows what the real resistance is. Second, he was technically correct about the battery playing a major part in filtering noise from the electrical system, but recommending a capacitor to fix a noise problem is completely ridiculous. Using a walkman to provide a signal to the amplifier will automatically remove a ground loop, since the walkman doesn't share the same ground as the amplifier. So even if you get clear sound with the walkman as a source, it doesn't mean the head unit is the culprit. The way to eliminate the head unit is to substitute another known-good head unit, not a portable player. I'd try re-grounding the amplifier to another point, and make sure you have a tight, paint-free ground connection. Double-check the head unit ground also. Check your battery connections and make sure they're tight and not corroded. Also check the connection between the chassis and the battery negative post. [/QUOTE]

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