bridge wires?

can i bridge 2 of the speakers to get more power out of them then wire the other 2 to mu HU?

i have the MTX mxa4004 4 channel amp. it is 50wx4 at 4ohm   100w at 2 ohm and 200watt bridged at 4ohm   

my speakers are infinity with 100 RMS and 350 watt total , i was thinking if i could bridge these, or would they be over powered and blown.

i also have rockfords which are 75watt RMS which could hook up to the head unit.

Bridging a speaker across two channels is the equivalent of running the amp at 2 ohms.  You notice how the power is doubled when the load goes from 4 ohm to 2 ohm. When you connect a 4 ohm load across 2 channels, it's each channel's output at a 2 ohm load.  That would be 200 watts into a 100 watt speaker.

You should never connect a speaker to an amp when it will get more power than what it is rated to get.  Especially that much more.  And you don't need to run that speaker with 100 watts for it to be loud.  50 clean watts is loud, and you have four of them.  I wouldn't suggest you run those speakers bridged in these circumstances...in fact, it would have to be a very compelling reason.  There's no reason.

The amp is bridgeable, and marketed like that, but you'll notice that they are referring to subwoofer bridging.  That is a different story altogether, and doesn't pertain to the mid and high range frequencies that your speakers have to reproduce clearly.  It is not uncommon to connect a 100 RMS speaker to a 50 watt source, and is done quite often, in fact.  The RMS of the speaker lets you know what it is capable of receiving all day long...but that doesn't mean it needs the 100 watts to play properly.

Connect the four speakers to the four-channel amp, adjust the gains, and enjoy your music.  If the rears seem a bit too loud, you can use your fader.