Attach a Speakon cable to one of the speaker jacks of the Behringer amplifier. This type of cable can handle large quantities of watts. Since many Behringer amplifiers exceed 500 watts, Speakon cables are the easiest, most stable way to transfer sound to your speakers. To secure the cable, insert it into the jack and turn it clockwise to lock it in place.
Attach the other end of the Speakon cable to the speaker, which is located on the back of the cabinet. If there are two jacks and they are not labeled, you can use either one as an input and the other as an output to another speaker cabinet. If one is labeled input, you should plug your power amp into that jack only. In most cases, you will be connecting to at least two speakers. This can be done in series or parallel.
To run your speakers in series mode, connect a second Speakon cable to the other jack on the back of the speaker cabinet. The sound will travel from one speaker to the next through the two cables. Because one speaker is now chained to another, the impedance is increased. Two 4-ohm cabinets will be seen as a total of 8 ohms load on the amplifier.
To run in parallel mode, connect another Speakon cable to the amplifier's second speaker output jack. Each speaker jack has its own minimum speaker impedance. If the load minimum is 4 ohms per channel and you are using two 4-ohm speaker cabinets, it is most efficient to run them in parallel mode.
Alternately, you can connect the power amp to speakers with bare wire or banana plugs, which are older style plugs that are sometimes used with high-wattage power amps. These connectors are readily available at electronics stores and are perfectly acceptable for use with Behringer power amps. They can be used exactly as seen in steps 1 through 4. This type of connection is less expensive than using Speakon cables. But Speakons are more secure, due to their built-in locking mechanisms.
Change the mode to the bridge setting by moving pins 6 and 7 to the right. These small switches are located on the back panel towards the left-hand side. All Behringer power amps are stereo and have two smaller power amps for the left and right sides that can be combined for mono usage. To connect a speaker or groups of speakers, use output 1 for Speakons or plug a banana cable into the two red inputs. This will usually give you exactly double the watts of each amp.