REL Connectivity

Always switch off your system before disconnecting any wires. To increase connection versatility, REL subs have one high-level and two low-level inputs: A Neutrik Speakon socket and two RCA phono sockets. This is to facilitate use with various system configurations. The high-level, unbalanced, dual-channel stereo input uses a Neutrik Speakon connector that is connected to the power amplifier’s left and right channel speaker terminals. This has the advantage of ensuring that the REL receives exactly the same signal as the main speakers. In this way, the character of the bass from the main system is carried forward into the sub-bass. This is a very important point and together with REL’s Input and Filter Circuitry ensures far superior system integration of the sub-bass with the main system. There is one RCA connection for line level connection to the output of a stereo preamplifier or receiver. Another single RCA connection permits connection to the .1/LFE output of a home cinema amplifier or processor.

The .1/LFE circuit is a dedicated channel used ONLY on AV processors or receivers fitted with Dolby Digital 5.1 or 7.1 systems. It is intended to provide theater lovers with a special Low Frequency Effects channel to better convey the director’s intent.

HIGH-LEVEL and .1/LFE inputs can and should be used simultaneously to achieve the best effect. The benefits are two-fold when used with a home cinema system. The .1/LFE input reproduces the .1 Sub/LFE channel and the high-level connection underpins the main front speakers thereby turning these into truly full range devices. Hint: The main front speakers must be set to ‘Large or Full Range’ operation on the processor, otherwise the main speakers will not receive the full range of bass intended for these channels and that your REL requires to properly operate. 

Connecting to the Power Amplifier Using the Speakon High-Level Input

To engage the Neutrik Speakon plug, insert fully into socket and rotate clockwise until locked. To remove the Neutrik Speakon plug, grip body of plug, place thumb on chrome lever, move lever backwards, rotate plug anti-clockwise quarter turn and withdraw.

Standard Connection

The standard high-level hookup procedure is: attach the red wire to the amplifier’s right positive speaker output terminal; attach the yellow wire to the amplifier’s left positive speaker output terminal; attach the black wire to whichever of the amplifier’s ground output terminals is convenient; plug the Speakon connector into the Sub-Bass System’s high-level input.

Differential or Class-D Amplifier Connection

For differential (i.e. fully balanced) amplifiers using one REL, simply use the standard connecting scheme with the exception of connecting the black wire to chassis ground (i.e. a metal bolt or screw, preferably not painted or anodized, on the chassis of the power amp or receiver), not to a negative speaker terminal, and then connecting into the HIGH-LEVEL INPUT on the REL.

Stereo Sub Connection

If connecting two RELs in a stereo configuration, connect the black wire of each REL to the negative speaker terminal of the corresponding amplifier channel; twist together the red and yellow wires of each REL separately and connect each pair to the positive speaker terminal of the corresponding amplifier channel.

Dedicated Center Channel Sub Connection

If connecting a single REL as a dedicated center channel sub, connect the black wire of the REL to the negative center channel speaker terminal; twist together the red and yellow wires and connect this pair to the positive center channel speaker terminal.

Dedicated Rear Sub Connection

If connecting a REL as a dedicated rear channel sub, connect the black wire of the REL to either the left rear or right rear negative speaker terminal; connect the yellow wire to the left rear positive speaker terminal; connect the red wire to the right rear positive speaker terminal.

Connectivity Specific to Gibraltar and Multiple Gibraltar Subwoofers

Gibraltar has two separate stereo inputs: A Neutrik Speakon socket and two phono sockets. This is to facilitate use with various system configurations.

The high-level, unbalanced, dual-channel stereo input uses a Neutrik Speakon connector that is connected to the power amplifier’s left and right channel speaker terminals. This has the advantage of ensuring that the REL receives exactly the same signal as the main speakers. This means that the character of the bass from the main system is carried forward into the sub-bass. This is a very important point and together with REL’s Active Bass Controller (ABC), ensures far superior system integration of the sub-bass with the main system. There are two RCA sockets for low-level connection to the output of a stereo preamplifier or receiver. Another single RCA socket connects to the .1/LFE output of a home cinema amplifier or processor.

HIGH-LEVEL and .1/LFE inputs can be used simultaneously. The benefits are two-fold when used with a home cinema system. The low-level input reproduces the .1 Sub/LFE channel and the high-level connection underpins the main front speakers. The main front speakers should be set to the ‘large’ option on the processor.

Connecting Multiple Gibraltar’s

For higher levels of low-frequency output, you may want to use multiple Gibraltar units. To facilitate this, the Gibraltar uses a rear panel high-level connector to “daisy chain” units when stacked vertically or placed next to each other. This connectivity allows for the same amplifier output signal to easily feed multiple sub-bass systems. Simply use the optional cable (Speakon-to-Speakon) to connect from the “HIGH-LEVEL OUTPUT” of the first sub-bass system to the “HIGH-LEVEL INPUT” of the second unit. When “daisy chained” each sub-bass system retains its autonomy and each will need to have its output level, crossover point, phase, etc. adjusted individually. This arrangement provides unrestricted flexibility for in-room integration and fine-tuning of all audio parameters.

For multi-channel home cinema systems, the same procedure is followed except a phono-to-phono cable is also used to connect the first sub-bass system “.1/LFE OUTPUT” to the “.1/LFE INPUT” of the second unit. As is typical for REL, both high-level and .1/LFE inputs can be used together and adjusted independently offering the ability to blend both signals to your taste. To protect Gibraltar ’s fine furniture grade cabinetry when stacking, optional rails with felt coverings that replace the metal feet are available. The kit contains all hardware necessary to attach the rails, as well as a Speakon-to-Speakon cable for daisy-chaining.