Re: 2- 6x9 at 4ohm or at 2ohms
To wire them to a 2 ohm load you would have to hook them up to a single channel. That's how it works when you wire speakers together to change the load they present. Unless they are on the same channel they don't affect each other.
That said, you will now be wasting the other channel of that pair and getting no power out of it, so while you might be getting more power out of the one channel it will not be more than double the 4 ohm power of both channels and you will leave you 6x9s running mon rather than stereo and sharing the 2 ohm power of 1 channel of a stereo amp. The result would likley be that the amp will run a bit hotter, the speakers will not be as loud (they would each be getting less power) and they would be running the signal of only one channel.
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