JL Audio XD600/1, XD400/4 owner manual Speaker Outputs, Do not do this

Speaker OUTPUTS

The XD400/4’s speaker outputs are designed to accept 16 AWG - 8 AWG wire. To connect the speaker wires to the amplifier, first back out the set screws on the top of the terminal block, using the supplied 2.5 mm hex wrench. Strip 1/2 inch (12 mm) of insulation from the end of each wire and insert the bare wire into the terminal block, seating it firmly so that no bare wire is exposed. While holding the wire in place, tighten the set screw firmly, taking care not to strip the head of the screw.

Each pair of the XD400/4’s channels are designed to deliver power into speaker loads equal to or greater than 2 ohms when using a “stereo” configuration and speaker loads equal to or greater than 4 ohms when using a “bridged” configuration.

Speaker loads below 2 ohms nominal per channel (or 4 ohms bridged) are not recommended and may cause the amplifier to initiate a protection mode which reduces power output.

Bridging Considerations Bridging is the practice of combining the

output of two amplifier channels to drive a single load. When bridged, each channel produces signals of equal magnitude, but opposite polarity. The combined output of the two channels provides twice the output voltage available from a single channel. The XD400/4 has been designed for bridging of its channel pairs without the need for input inversion adaptors.

To bridge a pair of channels, use the “Left +” and “Right –” speaker connectors only (the

“Left –” and “Right +” remain unused). When bridged, each channel will deliver optimum power into a 4 ohm load.

When a pair of channels are bridged, they will deliver 200W x 1 into a 4 ohm load or 150W x 1 into an 8 ohm load. Operating a pair of bridged channels into a load lower than 4 ohms is not recommended.

Because a bridged pair of channels requires that both channels receive input, you need to connect both left and right inputs to the source unit. Connection of only one input will result in reduced power output, increased distortion and can cause the amplifier to overheat.

Do not do this!

When a pair of the XD400/4’s channels are operating in bridged mode, the output will be in mono (only one channel). This mono channel can contain right channel only information, left channel only information or the sum of the information from both the right and left channels. In order to achieve one of these options, configure the inputs to that pair of channels in one of these two ways:

1)Left Channel Only or Right Channel Only Information: If you wish to send a left-only or right-only signal to a pair of the XD400/4’s channels, use a “Y-Adaptor” to split the single channel signal into both left and right RCA inputs. This option is useful when using a pair of the XD400/4’s channels to drive left channel speakers only and the other pair of the XD400/4’s channels to drive right channel speakers only.

2)Left + Right Channel Information: When bridged and fed by a stereo input, a pair of the XD400/4’s channels will automatically combine the left and right channels into a summed mono (left + right) channel. This option is useful when using a pair of the XD400/4’s channels to drive a subwoofer system or a summed mono center channel.