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<blockquote data-quote="thch" data-source="post: 6474726" data-attributes="member: 562032">make sure the speakers are not connected to the amp, and that you&#039;re not touching them.&nbsp; if they are connected to the amp, then you will be measuring something amp related.&nbsp; if the amp isn&#039;t turned on (or really, even if it is), the result will be off as the DMM will be attempting to measure the amp as well.likewise, the normal method the DMM uses will be off if you are tapping on the speakers as this generates some signal on the coils, and the DMM gets a bit confused.remember that the &quot;nominal impedance&quot; is different than the &quot;dc resistance&quot; of the coils.&nbsp; for an example, look at various speakers at partsexpress.&nbsp; many speakers in the woofers/subwoofers section have free-air impedance plots.&nbsp; of note is that the impedance (in free air) can be much higher then the DC resistance.modeling programs like winISD will show how various box types might affect this.&nbsp; The overall impedance of the speaker when playing &quot;music&quot; is based largely on mechanical properties of the box that are &quot;transduced&quot; into electrical properties like impedance.</blockquote>

[QUOTE="thch, post: 6474726, member: 562032"] make sure the speakers are not connected to the amp, and that you're not touching them. if they are connected to the amp, then you will be measuring something amp related. if the amp isn't turned on (or really, even if it is), the result will be off as the DMM will be attempting to measure the amp as well. likewise, the normal method the DMM uses will be off if you are tapping on the speakers as this generates some signal on the coils, and the DMM gets a bit confused. remember that the "nominal impedance" is different than the "dc resistance" of the coils. for an example, look at various speakers at partsexpress. many speakers in the woofers/subwoofers section have free-air impedance plots. of note is that the impedance (in free air) can be much higher then the DC resistance. modeling programs like winISD will show how various box types might affect this. The overall impedance of the speaker when playing "music" is based largely on mechanical properties of the box that are "transduced" into electrical properties like impedance. [/QUOTE]

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