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Date: May 06, 2001 at 23:32:49
From: Andy Walsh, [129.94.6.29]
Subject: Re: high current or not????


Nate is right.

It depends on the amp efficiency, which in turn is largely dependent on what supply voltage the internal DC/DC converter generates.
eg. A bridged 1000Wrms@4ohm amp might have VDC=+/-50V and draw 16 amps, but a bridged 1000Wrms@1 ohm amp might only generate VDC=+/-25V but draw 32 amps at rated output.
So although the 1 ohm amp has a higher current into the output stage, if both have equal efficiencies they will draw the same current from the 12V battery. (If the DC/DC converter is 70% efficient this will be 190A!!). This is such a stupidly high number I suspect that auto amps do not rate their amps by continuous RMS numbers.

All things being equal I'd go for the 4 ohm amp as being the more efficient as it is generally less efficient the greater the output current, but you cannot rely on this...

The best way to tell is to look at the specs...look for 12V supply current at rated output and choose the lower (if efficiency is your main concern). Of course you also need to check that they are talking about the same type of power. ie. continuous RMS is quite different to peak power etc...


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