if you have a 2 ohm stable amp does that count in bridged mode or can you only run 4 ohm bridged. im sure it depends on the amp so i have a mtx mxa3002 and it dosent say in the manual.
^^^ Yup. Because when bridged, each channel "sees" half of the load. So a 2 channel amp bridged at 2ohm puts 1ohm on each channel, which the amp can't handle.
If you want to join 2 speakers, you can connect them in series to double the impedance instead of parallel, which halves it. That's why some people recommend 8 ohm loads for a bridged amp.
your amp is 2 ohm stable in stereo and 4 ohm stable when bridged. you can put anything higher you want. you will receive no benefit in wiring two 4 ohm subs as 8 ohms for a mono load. just hook a sub up to each channel, if that's not enough power then you need a new amp.