Bridging question

[jbone]

I'm running a 4 Infinity Kappa 6X9's off of a 4004 Fosgate Punch amp and a 12 inch Fosgate sub off a 3002 watt Fosgate amp.
I'm happy with the sound, except for when I'm at the sandbar. From about 30-40 feet all I hear is base because my midrange is all down low. I want to add a set of 6X9's under the hatch to enhance the mids and highs at farther distance. Can I bridge these into channels 3&4? If so, what 6X9 would you recommend to carry good highs and mids?
Also is there a way to make these run only when the hatch is opened?

[Outnumbered]

Why don't you get some speaker switches from Radio Shack and just switch that pair as you need? As far as running them all together I am pretty sure it works like this but you may want to verify with a stereo guru:
Two speakers on one channel:
4ohm speaker + 4 ohm speaker = 2 ohm load on that channel
So you need to see if your amp is rated as stable to 2 ohms and check your speakers to be sure they are 4 ohms each. The lower the ohms the harder it is on the amp. The better amps are usually rated stable to lower ohm loads.

[ROZ]

As Outnubered said, you can add another pair of speakers wired parallel, but the resistance goes down. This means your amp will run harder and hotter. The amp is 2ohm stable and it will run hot, so improve air circulation/ventillation.
As far as running it only with the hatch up..... This can only be achieved by disconnecting the speakers at the amp, or you can run a cheap 2 channel amp. You can wire the 12v turnon to a toggle switch allowing this part of the system to be turned on at your will...

[rivercrazy]

You either need another amplifer or like was suggested switch one of the existing pairs off while using that under the hatch pair. Or run one pair of the existing speakers off the head unit if you want to run all three pairs without adding another amplifer

[jbone]

Thanks,
I'll try and run them parrallel and keep any eye on the amp temp. If it becomes a problem I'll wire in a switch for the hatch speakers.
Thanks for the input.
J