If you plan to add an aftermarket speaker to a stock infinity system you will be cutting back on power. Most aftermarket speakers are 4 ohm and most "upgraded" OEM speakers are 2 ohm so you're cutting the output in half. The's also the issue of any equalization that's built onto a DSP chip to make corrections in the poor performance of the OEM speaker to make them sound better. By adding an aftermaket speaker that does not have the same limitations you'll have an equalization mismatch; the result being possibly worse performance than when you started.
There is no DSP in the basic audio system but I had not analyzed the Infinity system.
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2006 CRD
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