In order to bridge the amp you will need to follow the manufacturers instructions. Not all amps bridge in the same manner. It depends on the internal design of the output stages. Most amps bridge by connecting the right (+) output terminal to the speaker's (in your case the subwoofer's) positive terminal, and the left (-) output terminal to the speaker's negative terminal. The remaining two terminals on the amp remain unconected. You may also need to press a switch in the input of the amp to the (mono) position, but then not all amps have that. Again, the above is the way that many amps in the market get bridged, but mot all of them. Some for example connect the right (-) and the left (+). That is why you will need to follow the manufacturer's instructions. If you do not have the manual or the amp does not state on it, then call the Kenwood technical support and they will tell you. Again, keep in mind that if your amp is not 2 Ohm stable you can not connect a subwoofer which has an impedance of less that 8 Ohm to the amp in a bridged configuration. If your amp is not 2 Ohm stable and your subwoofer is 4 Ohm (and most subs are), then you will not be able to bridge the amp with it. The solution will be to either get an 8 Ohm sub or add a second identical sub to your other extra channel.