Reference Sub-Bass System

Connecting and Setup

Always switch off your system before disconnecting any wires.

High-level connection, using the enclosed cable with the Neutrik® SpeakOn® connector, is always the first choice. This connection can be made without affecting the performance of the amplifier because the REL’s input will not impact the speaker load.

There are two XLR and two RCA sockets for low-level Left and Right channel connection to the output of a stereo preamplifier or receiver. These may be used in the case where high-level input is not an option.

XLR and RCA input connections are provided for input from the .1/LFE channel of a home cinema processor.

High Level Connection - Single Subwoofer

The standard high-level hook up 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 chassis ground screws or bolts is convenient. If the integrated amplifier or pre-amplifier you are using has a phono ground attach the black wire there; plug the SpeakOn® connector into the Sub-Bass System’s high-level input.

Connecting and Setup

Always switch off your system before disconnecting any wires.

High-level connection, using the enclosed cable with the Neutrik® SpeakOn® connector, is always the first choice. This connection can be made without affecting the performance of the amplifier because the REL’s input will not impact the speaker load.

There are two XLR and two RCA sockets for low-level Left and Right channel connection to the output of a stereo preamplifier or receiver. These may be used in the case where high-level input is not an option.

XLR and RCA input connections are provided for input from the .1/LFE channel of a home cinema processor.

High Level Connection - Stereo Pair 

A stereo pair is connected so that one REL is dedicated to each output channel.  The black wire of each is connected to a chassis ground screw or bolt.  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. In some instances, this will result in exceptionally high gain (output) from the RELs. If it seems simply too high in gain, please remove either the red or yellow wire from the twisted pair. This will reduce output by half and restore a natural dynamic.

When connecting RELs to Mono Bloc amplifiers (2) RELs, one for each amplifier, must be used. Connect the black wire of each REL to chassis ground screws or bolts of the corresponding amplifier channel. For the left channel the red and yellow wires are connected together to the positive output terminal of the left channel.  Then the red and yellow wires of the right channel are connected together to the positive output terminal of the right channel.  

Low Level Connection 

Low level connection (via RCA or XLR connectors) is always an option if high level connection is not possible. When connecting to the low level inputs in a system in which high level connection is not possible, such as if using internally-amplified speakers, connect left and right RCA cables between the LOW LEVEL INPUT jacks of the REL and the left and right channel outputs of your preamplifier.  

When using a stereo pair of RELs, connect the left output channel to the left REL and the right output channel to the right REL. 

 .1/LFE Connection 

When connecting to a home cinema system where there is a .1/LFE channel output, connect a single RCA to RCA or XLR to XLR cable between the sub output of the processor/receiver and the .1/LFE input jacks on the REL. 

Connecting and Setup

Always switch off your system before disconnecting any wires.

High-level connection, using the enclosed cable with the Neutrik® SpeakOn® connector, is always the first choice. This connection can be made without affecting the performance of the amplifier because the REL’s input will not impact the speaker load.

There are two XLR and two RCA sockets for low-level Left and Right channel connection to the output of a stereo preamplifier or receiver. These may be used in the case where high-level input is not an option.

XLR and RCA input connections are provided for input from the .1/LFE channel of a home cinema processor.

Connectivity for Line Arrays of No.35 or No.36, Multiple Sub-Bass Systems 

To render connectivity simple, No.35/ No.36 provides both inputs and outputs for all connections. Thus, each channel’s stack of No.35 or No.36 can be connected using only one high level main cable from power amp to REL stack. Then each input of the next in the stack can be connected from the last output.  This is referred to as "daisy chaining".    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.   

Theatre Connectivity for Line Arrays of No.35 or No.36, Multiple Sub-Bass Systems 

In a .1/LFE film sound configuration, each channel will require a single.1/LFE cable (either XLR or RCA connections are included) per L/R channel as well, but additional unit’s .1/LFE connections in a tower may be daisy chained to minimize clutter. Stacked No.35 and No.36 subs have the ability to effortlessly energize even very large theatres with huge wavefronts of air that will carry sound to the full height of the screen, an effect best demonstrated by removing the top level of subs, followed by the middle level to hear on screen events descend in their positioning. No.35 and No.36 Line Arrays possess the ability to convey the musical event or film sound spectacularly and with great ease. 

Theatre Connectivity for Line Arrays of No.35 or No.36, Multiple Sub-Bass Systems 

In a .1/LFE film sound configuration, each channel will require a single.1/LFE cable (either XLR or RCA connections are included) per L/R channel as well, but additional unit’s .1/LFE connections in a tower may be daisy chained to minimize clutter. Stacked No.35 and No.36 subs have the ability to effortlessly energize even very large theatres with huge wavefronts of air that will carry sound to the full height of the screen, an effect best demonstrated by removing the top level of subs, followed by the middle level to hear on screen events descend in their positioning. No.35 and No.36 Line Arrays possess the ability to convey the musical event or film sound spectacularly and with great ease. 

An LED display is located on the upper right front of both No.35 and No.36. All functions that are user adjustable via the remote control can be viewed here. The display reverts to off a few seconds after adjustment. The top three characters indicate the parameter being controlled by the remote and the bottom two numbers indicate the value of the parameter controlled.

No.35/ No.36’s Remote Control Unit requires two AAA batteries. These are not installed but are supplied. To install or replace batteries in the Remote Control Unit, first remove the bottom aluminum cover by using the supplied 2.5mm Hex key to loosen the two visible screws. With the bottom cover removed, you will see a battery holder, which will accept two AAA batteries. Follow the images on the holder for proper orientation of the batteries. After installing the batteries, test the unit by setting the SECURITY switch to UNLOCK and turning one of the knobs. If the batteries are installed properly, you will see one of the white LEDs on the remote control’s front panel illuminate. Replace the bottom cover and tighten the two screws using the supplied Hex key. Battery life can be extended if the SECURITY toggle switch is left in the LOCK position when the Remote Control is not in use.

Basic set-up should take no more than ten to fifteen minutes to accomplish once connected.

To begin the set-up process, select a piece of music that has a repetitive bass percussion line that is very low in frequency. We exclusively use “Cosmo…Old Friend”, which is track 4 from the soundtrack to Sneakers Film (Columbia CK 53146), and is the best REL setup track we’ve ever found and works perfectly for dialing in Position, and later, Phase and Crossover values. This has a repetitively struck bass drum that appears throughout, and that gives one plenty of time to move the subwoofer around whilst listening and making adjustments.

Positioning Single

The optimal position for a single REL No.35/ No.36 is in one of the corners behind the main speakers. This position provides 9 dB of room gain and allows for the best low bass extension. Do not simply place it as close the walls as possible. Instead, once basic optimization of Phase, Crossover and Gain have taken place, carefully move your REL in small increments whilst using cut #4 on the CD soundtrack of the movie Sneakers. Listen for pressure driven nodes. Choose the one that offers the best combination of deep bass with speed and delicacy.

Corning Placement Fine Tuning

The first step is to determine precisely how far from the corner the sub should be placed to achieve the most efficient output, as well as the lowest frequency extension. With each REL fully loaded into the corner, and toed-in toward the listening position, continue to play music while slowly drawing the REL out from the corner on the diagonal. As you do so, note certain points (sometimes a matter of only a few inches, in rare cases a foot or more) where the REL will audibly go lower, or play louder, and, if it truly locks on to the room and is fully pressurizing it, the air around the REL will feel more energized. Stop right there! This is the correct position from the corner for the REL.

Orientation, Fine Tuning Toe-In

Once the position from the corner has been established, the toe-in of the REL must be determined by rotating the REL from an imagined centre point at the rear of the REL. As the REL is toed-in from one side to the other, listen for the greatest level of output and bass linearity. In effect, the REL should be left in the position where it sounds both the richest and most focused. If your room is too full sounding, slightly toeing your REL out will result in reduction of richness but may be more desirable in rooms that output too much bass.

Positioning Dual  

Stereo Sub-Bass is advised for the fastest, clearest, deep bass—not simply for more output. Conventional wisdom has it that the use of stereo subs results in between +3 and +6 dB additional output depending upon positioning. In and of itself, this is of only passing interest since, in most instances, even a single No.35 or No.36 is capable of profound output. 

Setup

When setting up stereo No.35or No.36s, it is possible to place both units in the front corners of the room, carefully toed-in and placed per normal guidance in this manual. Connect each sub to the speaker terminal outputs based on the following diagrams for standard stereo amp, non-balanced mono blocks or balanced differential mono blocks. 

Depending upon your room’s character, it may be preferable to bring the subs further out into the room and place them slightly behind and outboard of the main speakers. 

1. Set each side up independently. Disconnect the sub that is not being set-up at that moment so your complete focus can be given over to the sub that is being set-up. 

Carefully follow the guidance provided in standard setup if you are unfamiliar with standard REL set-up procedure for gain, phase and crossover settings. 

2. Carefully fine-tune the position of the sub in its recommended location (slightly behind and to the outside of the main speaker) listening for rich powerful room nodes, but focusing on speed and connection with the main speaker. Since there will be a preponderance of output available to a stereo No.35/ No.36 owner, focusing on connection with and blending with the main speaker becomes the primary focus, not merely raw output.  

3. Once each sub has been carefully tuned, attach the cables for both subs. At this point, the output achieved will be too loud and will require re-setting the volume/gain control of each NO.35/ NO.36 lower. This is normal as the combined output is likely to be at least 3 dB louder with both subs now being used. Using the supplied remote, carefully turn down each sub until perfect balance is achieved. While turning the left or right sub gain down, it is helpful to turn slightly and even lean slightly toward the side that is being adjusted to better achieve focus and a balanced sound level more quickly. 

Positioning Line Array  

The line array positioning is the same process as described above for stereo pairs. Once the stereo pair is placed, the remaining units of the line array can be stacked on top.  

Stacking  No.35 and No.36 are designed to allow multiple units to be used in conjunction either as stereo pairs or, for ultimate performance, in vertical tower stacks of stereo subs 3 per side (or 5/side in exceptionally tall rooms). Stacked towers extend and strengthen the performance remarkably.   

REL Couplers are provided to secure the top sub to the next unit below safely.  These are made of thick aluminium and bolt the subs together using the hardware provided.  The Couplers require a 6mm hex wrench to tighten.    

We strongly advise anchoring Line Array stacks of the No.35 or No.36 to a wall.  Use a quality furniture restraint made of nylon webbing or braided steel cable that may be tied to one of the upper REL Coupler, generally that which is closest to a side or rear wall.  Please follow the instructions of the restraint you choose and anchor to a structural portion of your wall.  

Please ensure that the floor is level before stacking REL reference subwoofers and avoid stacking on deep carpet that may not provide a stable surface.  

REL Reference subwoofers have rake adjuster disks on the front of the feet to tilt the units back.  There are two, one in each foot and they have to be backed out independently.  A rake adjustment tool is included to help rotate the adjuster to back out and raise the front of the subwoofer.  

The Process

To begin the set-up process, select a piece of music that has a repetitive bass percussion line that is very low in frequency. We exclusively use “Cosmo…Old Friend”, which is track 4 from the soundtrack to Sneakers (Columbia CK 53146), and is the best REL setup track we’ve ever found and works perfectly for dialing in Phase, Crossover, and Level values. This has a repetitively struck bass drum that appears throughout, and that gives one plenty of time to move the woofer around whilst listening and making adjustments.

1. Phase Orientation: Once in the corner, we need to adjust for phase. This may be the single most critical step, and because it is so simple, it is often over-thought. Keep in mind; the correct phase is whichever setting (0 or 180 Degrees) is the loudest or fullest. While playing “Cosmo…Old Friend”, adjust Hi/Low Level to a point where the REL and the speaker appear to blend at the REL. During this process, leave the Crossover at its lowest setting as this ensures that you are correctly achieving a Phase result based on deepest bass. Simply switch between “0” and “180” phase positions listening for whichever position is loudest or fullest. This is the correct position. That is, this is the position that is working in harmony with your main speakers, reinforcing bass, not cancelling it.   

2. Crossover and Level Settings: To determine the crossover point, take the volume of the REL (using the Hi/Low Level control) all the way down, and set the Crossover to 30 Hz as an initial setting. Now, begin adjusting the Hi/Low Level control back up slowly to the point where you have achieved a delicate balance, i.e. the point at which you can just hear the No.35/ No.36 even with the main speakers playing. We suggest bringing the crossover point up until it is obviously too high; then gently reducing frequency until the perfect balance has been achieved. For all intents and purposes, this is the correct crossover point. Once this stage has been reached, subtle changes to Level and Crossover may be accomplished to provide the last bit of complete and seamless integration. With that, set-up is complete. 

Crossover and Level Settings

The process to tune a stereo pair is the same as above with a single REL, but you focus on one channel at a time.  With the stereo system on, unplug the inputs to one REL then tune the other using the guidance above.  Then plug the inputs back into the first REL, disconnect the already tuned one, and tune the first REL using the steps above.  

Once each sub has been carefully tuned, attach the cables for both subs. At this point, the output achieved will be too loud and will require re-setting the Level control of each No.35/ No.36 lower. This is normal as the combined output is likely to be at least 3 dB louder with both subs now being used. Using the supplied remote, carefully turn down each sub until perfect balance is achieved. While turning the left or right sub gain down, it is helpful to turn slightly and even lean slightly toward the side that is being adjusted to better achieve focus and a balanced sound level more quickly.  

Tuning of a REL Reference Line Array

Tuning of a Reference Line Array starts with proper setup and tuning of your system’s main loudspeakers. Only after the main speaker channels are performing to their fullest potential will you be able to achieve the full performance potential of a REL Line Array. Next, you can position and tune the bottom stereo pair of subwoofers (the bottom unit in each stack), using the instructions in the stereo pair section above. After the bottom units have been tuned to blend seamlessly with your main loudspeakers, you can then carefully place the additional Reference subwoofers on top of them to form the complete Line Arrays.   

The Phase setting for the middle and upper units in each stack will remain the same as the bottom units. Similar to the process for tuning a stereo pair, the Crossover and Level control settings for each subwoofer in the Line Array should be determined with only one subwoofer playing at a time. This means that once the bottom units in each stack are tuned, you will tune the middle right unit on it’s own, followed by the middle left, then the upper right, and so on until all units are blending well on their own.    

The middle subwoofer in each stack is responsible for mid bass attack. Don’t worry about getting the deepest bass or upper bass partials, but focus on achieving crisp mid bass performance. When using “Cosmo…Old Friend”, listen for the sound of the mallet hitting the skin of the concert drum, which should have clear and crisp definition.  

The upper subwoofer in each stack is responsible for air, openness, and delicacy in the program material. This is the transition between the sub-bass and the low-frequency output of the main loudspeakers. It is expected that the Crossover and Level controls will need to be set slightly higher as you move up in each stack, compared to the below unit.

Once each individual subwoofer in each stack is tuned on it’s own, you can connect the necessary cables to daisy-chain the signal. At this point the overall sub-bass output will be too high, and the Level on each subwoofer will need to be lowered equally to restore a match with your main loudspeakers. From there you can make any final adjustments to the Crossover and Level controls as needed to achieve the desired performance and integration.

Applications  

Your REL Reference Series subwoofer features both a HIGH LEVEL INPUT and a .1/LFE INPUT, and for home theater systems we recommend using both simultaneously. This allows the subwoofer to provide low-frequency support with seamless integration for your choice of main speaker channels, while also delivering the LFE (Low Frequency Effect) channel found in home theater material. In systems which use active speakers, or in other specific scenarios, it is possible to use the REL’s Low Level input and the .1/LFE input simultaneously.     

Basic AV Receiver/Processor Settings  

Each AV receiver or processor will have slightly different setup menu options, but the same general principles will still apply. We recommend setting your main speaker channels to “large” or “full-range” output, which will ensure that you achieve the full performance potential of the High/Low Level connection. If your receiver or processor does not allow for full-range output during multi-channel listening, then please set the main speaker channels’ crossover to the lowest possible value. Also check to make sure that you select “Yes” or “On” for the subwoofer output, which will ensure that LFE channel signal reaches your REL.  

Single Home Theater Setup

Please first follow the high level or low level connection instructions, placement instructions, and tuning instructions outlined earlier in this manual. We find that the best results with a single subwoofer or with a stereo pair come by connecting the high level cable(s) to the front left and right speaker channels, which provides the greatest benefit across most listening scenarios.

Once the subwoofer has been connected and tuned to blend with your main loudspeakers, you can then use either an RCA or XLR cable for connecting from the subwoofer output on your receiver/processor to the .1/LFE input on the REL. At this point you will only need to adjust the .1/LFE Level control to taste for achieving the desired amount of LFE channel output. We recommend using a powerful and dynamic action or effect heavy scene when setting the .1/LFE Level, for example Chapter 14 from Iron Man. Set the .1/LFE Level through your Reference Remote so that the sub-bass output is powerful and dynamic but without any strain or distortion being heard from the subwoofer.  

Applications  

Your REL Reference Series subwoofer features both a HIGH LEVEL INPUT and a .1/LFE INPUT, and for home theater systems we recommend using both simultaneously. This allows the subwoofer to provide low-frequency support with seamless integration for your choice of main speaker channels, while also delivering the LFE (Low Frequency Effect) channel found in home theater material. In systems which use active speakers, or in other specific scenarios, it is possible to use the REL’s Low Level input and the .1/LFE input simultaneously.     

Basic AV Receiver/Processor Settings  

Each AV receiver or processor will have slightly different setup menu options, but the same general principles will still apply. We recommend setting your main speaker channels to “large” or “full-range” output, which will ensure that you achieve the full performance potential of the High/Low Level connection. If your receiver or processor does not allow for full-range output during multi-channel listening, then please set the main speaker channels’ crossover to the lowest possible value. Also check to make sure that you select “Yes” or “On” for the subwoofer output, which will ensure that LFE channel signal reaches your REL.  

Home Theater Setup

Again, first follow the high level or low level connection instructions, placement instructions, and tuning instructions outlined earlier in this manual. We find that the best results with a stereo pair come by connecting the high level cable(s) to the front left and right speaker channels, which provides the greatest benefit across most listening scenarios. 

Once the stereo pair is integrated into your system, you can then use either an RCA or XLR cables for connecting from the subwoofer outputs on your receiver/processor to the .1/LFE inputs on the RELs. At this point you will only need to adjust the .1/LFE Level control to taste for achieving the desired amount of LFE channel output. We recommend using a powerful and dynamic action or effect heavy scene when setting the .1/LFE Level, for example Chapter 14 from Iron Man. Set the .1/LFE Level through your Reference Remote so that the sub-bass output is powerful and dynamic but without any strain or distortion being heard from the subwoofer.  

Applications  

Your REL Reference Series subwoofer features both a HIGH LEVEL INPUT and a .1/LFE INPUT, and for home theater systems we recommend using both simultaneously. This allows the subwoofer to provide low-frequency support with seamless integration for your choice of main speaker channels, while also delivering the LFE (Low Frequency Effect) channel found in home theater material. In systems which use active speakers, or in other specific scenarios, it is possible to use the REL’s Low Level input and the .1/LFE input simultaneously.     

Basic AV Receiver/Processor Settings  

Each AV receiver or processor will have slightly different setup menu options, but the same general principles will still apply. We recommend setting your main speaker channels to “large” or “full-range” output, which will ensure that you achieve the full performance potential of the High/Low Level connection. If your receiver or processor does not allow for full-range output during multi-channel listening, then please set the main speaker channels’ crossover to the lowest possible value. Also check to make sure that you select “Yes” or “On” for the subwoofer output, which will ensure that LFE channel signal reaches your REL.  

Home Theater Setup 

Once the high level or low level connection and tuning is done following the instructions in the POSITIONING and TUNING guides, the home theater connections can be connected and set up.  

From the subwoofer outputs (SUB OUT) of your receiver/ home theater processor, connect to the .1/LFE INPUT of the bottom units of each channel of the line array.  Nearly all modern processors have at least two SUB OUT channels in either RCA or XLR type connections.  Use just one of these types of connections to connect from the processor to the RELs.  Each REL has .1/LFE outputs in both of these types of connections so you can use jumpers to connect out of the first unit of the line array to the next.  Then from the second unit to the third unit and so on.  Previously, this type of connections has been referred to as “daisy chaining” which means we connect the output of one REL to the input of the next.  Repeat this for both channels of the line array and ensure that all of them are connected.    

You will now need to adjust the .1/LFE Level for each unit in the line array using the remote control to taste for achieving the desired amount of LFE channel output. We recommend using a powerful and dynamic action or effect heavy scene when setting the .1/LFE Level, for example Chapter 14 from Iron Man. Set the .1/LFE Level through your Reference Remote so that the sub-bass output is powerful and dynamic but without any strain or distortion being heard from the subwoofer.  

Your No.35 or 32 is equipped with (2) Parametric Equalizers. It is not recommended that average users attempt to use the parametric equalizers included in No.35/ No.36 as mis-application of these filters can produce results detrimental to the average room or in extreme cases, create the slight risk of damage to your REL. No.35/ No.36 provides for 2 parametric filters that may be used to cure certain room acoustics challenges. Use of these should very much be seen as optional, and engaging either requires physically turning on the toggle switch on the rear panel that supplies power to BOTH parametric EQ’s. These 2 filters provide for up to 4 dB of boost or cut at any frequency between 23 and 90Hz. Note that the frequencies of each filter cannot be closer than 10Hz apart from each other. This is done to minimize the chances an inexperienced owner could damage their REL accidentally. For example, if E1 is set to 30Hz, E2 cannot be set below 40Hz. This is done to protect the Sub-Bass system.

Attempting to use any filter to produce perfectly flat response is a fool’s errand. Best results will be achieved by gentle application of gain or cut functions.

Adjusting the Parametric Filters 

Set the Filter switch on the REL’s rear panel to “On” to allow filters to be accessed. Locate the silver selector switch in the center location on the remote marked Parametric.  With the switch in the far left position, the .1/LFE Level control on the remote now changes the frequency of EQ filter 1, and the Hi/Low Level control on the remote changes the level of EQ filter 1.  With the switch in the far right position, the .1/LFE Level control on the remote changes the frequency of EQ filter 2, and the Hi/Low Level control on the remote changes the level of EQ filter 2.  Each filter has a frequency range of 23Hz to 90Hz.  The amount of level being increased or decreased for each filter is +/- 4dB in 1/3 dB increments.    

REL No.35 & No.36 Reference Series

Please review the following safety precautions before installing, connecting, or operating your REL No.35 or No.36 Reference Sub-Bass System. 

Electrical Connections 

• Do not connect the black ground wire to an amplifier output terminal. Connect it to an appropriate chassis ground point. 
• When connecting to monoblock amplifiers, always use a stereo pair of REL subwoofers, with one unit connected to each amplifier. Connecting a single Reference subwoofer to a pair of monoblock amplifiers may cause ground-loop hum or, in some circumstances, oscillation. 
• Always switch off your system before disconnecting any cables. 

Safe Placement and Stacking 

• No.35 and No.36 subwoofers are large and heavy. Take special care when moving or lifting them. REL recommends having three people available to move these units. 
• Ensure the floor is level and stable before stacking subwoofers. Avoid stacking on deep carpet that may not provide adequate stability. 
• Secure all Reference Line Array stacks to a structural wall using a suitable furniture restraint made from nylon webbing or braided steel cable. Follow the restraint manufacturer's installation instructions and ensure the restraint is securely anchored. 

Parametric Equalizer Caution 

• The No.35 and No.36 feature two optional parametric equalizers designed to address specific room-acoustic challenges. Incorrect use may negatively affect sound quality and, in extreme cases, risk damage to the subwoofer. 
• These controls are intended for careful, informed adjustment. Avoid aggressive boosts or cuts over narrow frequency ranges. Gentle adjustments are recommended for the best results. 

Initial Run-In 

• During the initial run-in period, use your subwoofer at moderate levels. The electronics and drive unit benefit from a period of controlled operation, and the manual recommends approximately 24 hours of actual use. Avoid playing at maximum volume immediately after installation, as excessive initial levels may cause damage. 

Overload and Thermal Protection 

REL subwoofers include Set-Safe™ electronic protection and a thermal overload device. However, these systems do not eliminate the risk of damage from excessive output. 

Listen for signs of strain or distortion and reduce the volume when necessary. If the thermal protection activates and the output cuts out, allow approximately five minutes for recovery and reduce the volume to a safe level before continuing. 

Damage caused by deliberate or excessive overdriving is not covered by warranty.