Pioneer 4 channel amp (GM-D9500F)
75 RMS x 2 channels (A)
150 RMS bridged channel (B)
150 Watt 8" footwell sub
2 Polk Audio 4 x 6 50RMS (150 peak)

A few questions if you don't mind...speak slowly The manual was written in like font 4...who do they think reads these things?
Currently I have my ipod plugged into the RCA input for A. Should I split the signal for A and B?

Should I have it on 2 or 4 channel (I have 3 channels due to the B being bridged)?

LPF/OFF/HPF Both sides have this selector switch? Currently I have both switched to off.

How do you best set the gain and frequecy for each channel?

Your amp is a 4 channel version. Use a splitter and inputs A & B. Use A for the front mid/high speakers and use B for you woofer, bridged. Turn the LPF/OFF/HPF to OFF on channel A. Turn to LPF on channed B. The GAIN should match the radio output (IPOD) put the dial in the middle to satrt with. Most likely you can leave it there.

Thanks Mike for all the help....
Just to clarify...switch it to 4 channel, along with the other settings as you mentioned?

Yes

you need to look in your manual. Likely if you use the switch on two channel, it will send the same input to the other two channels as well. That will save you a splitter.

If you are running the highs off the front two channels, and the sub off the rear channels, bridged, you could use the internal crossover.

Set the front channels to HPF (High Pass Filter) and set the frequency to where you want it to cut off. For 4x6 inch speakers I would recommend no lower than 200 hz, but you will need to see where they sound good.

Set the rears to LPF. Set the crossover frequency to the same frequency.

As for the gains, start low and work your way up very slowly. I could tell you the right way to do it, but it would require you to buy a oscilloscope.