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<blockquote data-quote="John Roberts" data-source="post: 145781" data-attributes="member: 126">Re: Damping Factor - Actual listening tests?Except that it is DF so that bast describes it. It is already quantified, but wrt to a resistive load. To put it in terms of a loudspeaker&#039;s deviation from ideal behavior we need to know more about that loudspeaker (VC mass, box alignment, etc??). Clearly a large sub will have more moving mass than a tweeter.OK Mr. Extreme. If you are stuck with hundreds of feet of modest gauge wire inside a conduit, and no power available at the speaker end to support locating the amps there, the obvious way to finesse the wire impedance is step-up/down transformers.&nbsp; You should recall from your engineering education that transformers &quot;transform&quot; the impedance by the square of the turn ratio. So a simple 1:4 step up transformer, with 4:1 step down at the far end, you will drop the effective wire impedance by a factor of 1/16th. Of course for running the signals in conduit you need to account for voltage if 4x the amp voltage exceeds wire insulation class. I have seen large instals that stacked 3 70V transformers in series to send audio over miles of wire at 210V nominal. Getting audio transformers that pass very low frequency will not be cheap, but that seems like one way to skin your cat. I repeat again, are you sure you have a problem? Or a problem worth this much expense and worry?Good luck.JRPS I don&#039;t expect a meaningful back of the envelope calculation. Since you should have a speaker in mind, perhaps do some experiments with driving one through an elevated resistance.</blockquote>

[QUOTE="John Roberts, post: 145781, member: 126"] Re: Damping Factor - Actual listening tests? Except that it is DF so that bast describes it. It is already quantified, but wrt to a resistive load. To put it in terms of a loudspeaker's deviation from ideal behavior we need to know more about that loudspeaker (VC mass, box alignment, etc??). Clearly a large sub will have more moving mass than a tweeter. OK Mr. Extreme. If you are stuck with hundreds of feet of modest gauge wire inside a conduit, and no power available at the speaker end to support locating the amps there, the obvious way to finesse the wire impedance is step-up/down transformers. You should recall from your engineering education that transformers "transform" the impedance by the square of the turn ratio. So a simple 1:4 step up transformer, with 4:1 step down at the far end, you will drop the effective wire impedance by a factor of 1/16th. Of course for running the signals in conduit you need to account for voltage if 4x the amp voltage exceeds wire insulation class. I have seen large instals that stacked 3 70V transformers in series to send audio over miles of wire at 210V nominal. Getting audio transformers that pass very low frequency will not be cheap, but that seems like one way to skin your cat. I repeat again, are you sure you have a problem? Or a problem worth this much expense and worry? Good luck. JR PS I don't expect a meaningful back of the envelope calculation. Since you should have a speaker in mind, perhaps do some experiments with driving one through an elevated resistance. [/QUOTE]

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