Audiosource amp three bridging questions

locnguyen26

Hi, I have an Audiosource model amp three that I am trying to bridge for my speakers. I noticed that there are 4 speaker posts in the back and speaker A and/or B selectors in the front. I know I can bridge this amp by following the owners manual to connect the positive of the left speaker to the positive of the right speaker. My question is I am curious to see if I need to get two of these amps to run both my speakers or can I bridge it so I can get both speakers at the 400wpc it claims. My speakers are 4 ohm speakers. Any help would be greatly appreciated. I just don't want to blow my speakers out. I don't understand why these two channel amps have 4 speakers. If I run all four speakers at once for say, is that mean that each speaker is getting 150 watts? Because the specs saids that it's 150w x 2 @ 8 ohms. Thanks in advance