I find some of the posts so amusing. Half the people don't have a clue of what they are talking about and the other group is right on electronically speaking.
Bridging the amps does NOT change the Z of the speakers, nor impact the amps ability to drive it. All decent amps can handle 4 ohms. but not all amps should be bridged. Also a speaker may be nominally 4 ohms but over the entire 20 to 20K range the Z can dip to one or two ohms. This is the point where some amps have trouble. Also some amps cannot deliver high current. Some speakers need high current. Best to make sure what the speakers really need and what the Z curve is. Lastly, listen at home BEFORE YOU BUY.
Bridging the amps does NOT change the Z of the speakers, nor impact the amps ability to drive it. All decent amps can handle 4 ohms. but not all amps should be bridged. Also a speaker may be nominally 4 ohms but over the entire 20 to 20K range the Z can dip to one or two ohms. This is the point where some amps have trouble. Also some amps cannot deliver high current. Some speakers need high current. Best to make sure what the speakers really need and what the Z curve is. Lastly, listen at home BEFORE YOU BUY.