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<blockquote data-quote="thisisausername" data-source="post: 8220360" data-attributes="member: 565137">yeah unfortunately 120v audio stuff is usually more expensive than car audio //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif . Not totally sure but I think I know a reason. I&#039;ve done a good bit of research into switching power supplies, it was for an inverter based welder but principle is the same. Inside the amp you have a Power Factor Corrector before the main switching stage and, at least for me, that ended up being far more expensive to build than the switching part itself. To spare the details the PFC stage is used because with AC current, a switching supply without one would only draw power from the peaks of the wave. This would distort the mains power circuit really bad and also puts tons of pressure on the capacitors and rectifier for the main stage. I read that most class D mains amps can only provide their RMS rating for about 20ms then they drop down to about half power. 20 ms is coincidentally about how long it would take to drain the stored energy in the PFC stage if it was designed to handle about half the rated power.The relevance of that rant is that since cars use DC they don&#039;t need a power factor correction stage at all. That effectively eliminates the first half of a regular mains amp. 12V is also a really friendly voltage for IC&#039;s and micros so you also save by not having a separate power supply to run the main amplifiers switches and such.</blockquote>

[QUOTE="thisisausername, post: 8220360, member: 565137"] yeah unfortunately 120v audio stuff is usually more expensive than car audio [IMG]//content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif[/IMG] . Not totally sure but I think I know a reason. I've done a good bit of research into switching power supplies, it was for an inverter based welder but principle is the same. Inside the amp you have a Power Factor Corrector before the main switching stage and, at least for me, that ended up being far more expensive to build than the switching part itself. To spare the details the PFC stage is used because with AC current, a switching supply without one would only draw power from the peaks of the wave. This would distort the mains power circuit really bad and also puts tons of pressure on the capacitors and rectifier for the main stage. I read that most class D mains amps can only provide their RMS rating for about 20ms then they drop down to about half power. 20 ms is coincidentally about how long it would take to drain the stored energy in the PFC stage if it was designed to handle about half the rated power. The relevance of that rant is that since cars use DC they don't need a power factor correction stage at all. That effectively eliminates the first half of a regular mains amp. 12V is also a really friendly voltage for IC's and micros so you also save by not having a separate power supply to run the main amplifiers switches and such. [/QUOTE]

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