REL Acoustics T/i Series User manual

Operang Instrucons for the
S e r i e T / i
S u b - B a s s
S y s t e m s
REL Acouscs Limited
North Road, Bridgend industrial Estate . Bridgend, CF31 3TP . United Kingdom
Telephone: [phone] . Fax: [phone]
Web: www.rel.net

2
Cauon Marking Explanaon
The lightning ash with arrowhead symbol within an equilateral triangle is intended to alert the
user to the presence of un-insulated dangerous voltage within the product’s enclosure that may
be of sucient magnitude to constute a risk of electric shock to persons.
The exclamaon point within an equilateral triangle is intended to alert the user to the presence
of important operang and maintenance (servicing) instrucons in the literature accompanying
the appliance.
Important Safety Instrucons ........................................................................................................................... 3
Informaons Importantes Relaves a la Securite ............................................................................................ 6
Welcome to the REL Family .............................................................................................................................. 8
REL Serie S Rear Panel Connecon Legend ..................................................................................................... 9
Connecng Up ............................................................................................................................................... 11
REL Set-Up Made Simple ............................................................................................................................... 13
Technical ........................................................................................................................................................ 20
T/9i Specicaons .......................................................................................................................................... 23
T/7i Specicaons .......................................................................................................................................... 24
T/5i Specicaons .......................................................................................................................................... 25
Table of Contents

3
1 Read all of these instrucons.
2 Save these instrucons for future use.
3 Heed all warnings.
4 Follow all instrucons.
5 Do not use this apparatus near water.
6 Clean only with automove polish and micro ber cloth.
7 Install in accordance with the manufacturer’s instrucons.
8 Do not install near any heat sources such as radiators, heat registers, stoves or other apparatus (including
ampliers) that produce heat.
9 Do not defeat the safety purpose of the grounding-type plug. A grounding type plug has two blades and
a third grounding prong. The third prong is provided for your safety. If the provided plug does not t into
your outlet, consult and electrician for replacement of the obsolete outlet.
10 Protect the power cord from being walked on or pinched parcularly at plugs, convenience receptacles,
and the point where they exit from the apparatus.
11 Only use aachments/accessories specied by the manufacturer.
12 Use only with a cart, stand, tripod, bracket, or table specied by the manufacturer, or sold with the
apparatus. When a cart is used, use cauon when moving the cart/apparatus combinaon to avoid
injury from p-over.
13 Unplug this apparatus during lightning storsm or when unused for long periods of me.
14 Refer all servicing to qualied service personnel. Servicing is required when the apparatus has been
damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects
have fallen into the apparatus, the apparatus has been exposed to rail or moisture, does not operate
normally, or has been dropped.
Cauon: Any changes or modicaons not expressly approved by the party responsible for compliance could
void the user’s authority to operate this equipment.
Important Safety Instrucons
4
Warning / Averssement
To reduce the risk of re or electric shock, do not expose this apparatus to rain or moisture.
Cet arcle est lourd. Pour éviter tout risque de blessure, prendre soin lors de la manipulaon.
The apparatus shall not be exposed to dripping or splashing and no objects lled with liquids, such as vases,
shall be placed on apparatus.
L’ appareil ne doit pas être exposé à des éclaboussures et aucun objet rempli de liquide, comme des vases,
ne doit être placé sur l’appareil.
The mains plus is used as disconnect device. The mains plug of the apparatus should not be obstructed OR
should be easily accessed during intended use. To be completely disconnected from the power input, the
mains plug of the apparatus shall me disconnected from the mains.
An appliance with a protecve earth terminal should be connected to a mains outlet with a protecve earth
connecon.
Les conduites Plus est ulisé comme disposif de déconnexion. La che de l’appareil ne doit pas être
obstruée OU doit être facilement accessible pendant l’ulisaon. Pour être complètement déconnecté de
l’alimentaon électrique, le cordon d’alimentaon de l’appareil doit me débranché.
Un appareil avec une borne de terre doit être branché sur une prise de courant en étant relié à la terre.
Design Safety
This apparatus is supplied with a detachable mains cord. For 230V operaon a 1.6A/ T/5i, 2A/ T/7i, 3.15A/
T/9i fuse is ed in the socket, for 120V operaon a 3.15A/ T/5i, 4A/ T/7i, 6.3A/ T/9i fuse is ed. Should
the fuse need to be replaced use a similar rated fuse approved to ASTA or BSI 362 standards. Do not use
without the fuse cover in place. Replacement fuse covers are available from your distributor.

5
Aenon Explicaon Marquage
L’éclair avec le symbole de pointe de èche dans un triangle équilatéral est desné à alerter l’
ulisateur de la présence de non isolée tension dangereuse à l’intérieur de l’enceinte du produit qui
peut être d’une ampleur susante pour constuer un risque d’électrocuon pour les personnes.
Le point d’exclamaon dans un triangle équilatéral est desné à alerter l’ulisateur de la présence
d’instrucons dans la documentaon accompagnant l’appareil exploitaon et de maintenance
(entreen).
6
1 Lisez aenvement ces instrucons.
2 Conservez ces instrucons.
3 Respectez tous les averssements.
4 Suivez toutes les instrucons.
5 Ne pas uliser cet appareil près de l’eau.
6 Neoyez seulement avec du vernis automobile et ssu microbre.
7 Installer conformément aux instrucons du fabricant.
8 Ne pas installer près de sources de chaleur telles que des radiateurs, registres de chaleur, poêles ou
autres appareils (y compris les amplicateurs) qui produisent de la chaleur.
9 Ne pas contourner le disposif de sécurité de la prise de terre. Une che de terre a deux lames et une
troisième broche de mise à la terre. La troisième broche est fournie pour votre sécurité. Si la che fournie
ne rentre pas dans votre prise, consultez un électricien pour le remplacement de la prise obsolète.
10 Protégez le cordon d’alimentaon ne soit piéné ou pincé, en parculier au niveau des ches, des prises
de courant, et le point de sore de l’appareil.
11 Ulisez uniquement des xaons / accessoires spéciés par le fabricant.
12 Ulisez seulement avec un chariot, stand, trépied, support ou table spécié par le fabricant, ou vendu avec
l’appareil. Lorsque vous ulisez un chariot, soyez prudent lorsque vous déplacez l’ensemble chariot / appareil
pour éviter les blessures en cas de chute.
13 Débranchez cet appareil pendant un orage ou lorsqu’il est inulisé storsm pour de longues périodes de temps.
14 Conez toute réparaon à un personnel qualié. Une réparaon est nécessaire lorsque l’appareil a été
endommagé de quelque façon que ce cordon d’alimentaon ou la che est endommagé, du liquide a
été renversé ou des objets sont tombés dans l’appareil, l’appareil a été exposé à rail ou à l’humidité, ne
fonconne pas normalement, ou a été échappé.
Aenon: Tout changement ou modicaon non expressément approuvés par la pare responsable de la
conformité pourraient annuler l’autorité de l’ulisateur à uliser cet équipement.
Informaons Importantes Relaves a la Securite

87
Sécurité Design
Cet appareil est livré avec un cordon amovible cordon. Pour le fonconnement d’un fusible de 230V 1.6A/
T/5i, 2A/ T/7i, 3.15A/ T/9i est montée dans la douille, pour le fonconnement de 120V un fusible de 3.15A/
T/5i, 4A/ T/7i, 6.3A/ T/9i est monté. Si le fusible doit être remplacé ulisaon un fusible similaire approuvé
pour ASTA ou BSI normes 362. Ne pas uliser sans le couvercle de fusible en place. Les couvercles de rechange
sont disponibles auprès de votre distributeur.
FCC STATEMENT
This device complies with Part 15 of the FCC Rules. Operaon is subject to the following two condions:
(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including interference that may cause
undesired operaon.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital Device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable protecon against harmful interference in a residenal installaon.
This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the
instrucons, may cause harmful interference to radio communicaons. However, there is no guarantee that the interference will not
occur in a parcular installaon. If this equipment does cause harmful interference to radio or television recepon, which can be
determined by turning the equipment o and on, the user is encouraged to try and correct the interference by one or more of the
following measures:
Reorient or relocate the receiving antenna.
Increase the separaon between the equipment and receiver.
Connect the equipment into an outlet on a circuit dierent from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.
Thank you, your new SerieT/i is designed to set a new standard for excellence in its category. T/i is beer in
every way than the previous generaon Serie T, which itself set new standards for performance, reliability
and beauty in design. The REL design team had to re-think how subwoofers were likely to be used in the
years to come and we believe we have hit the precise balance of ease of use, upgraded sonic performance
and we even managed to improve on the physical beauty and quality of nish.
Wait ll you experience the oponal Arrow™ wireless system. There’s nothing quite like realizing you really
can have it all; great performance and no visible wires. The key to its excellence is its speed which is like
nothing in the more common Bluetooth et al consumer-based systems. Latency, or delay, is the great bugaboo
of wireless systems because it can rob music and lm of all the warmth, punch and excitement of the real
thing. Arrow operates in the region of 15-22 milliseconds, which is many mes faster than more common
systems and results in performance very close indeed to the performance of a hardwired connecon.
Our engineers focused on bringing as much of the power, speed, slam (and delicacy) of our larger models to
T/i. We make extensive use of aluminium bracing in our new cone structures to produce a lighter and much
more rigid piston to drive the dynamics of music and lm with greater authority. We even removed the carbon
black from our cones because the added mass slowed the sound noceably. White, it’s the new black.
The one thing we didn’t change was the now-classic REL Class A/B power ampliers because no other
designs at anything close to these prices deliver the combinaon of rugged reliability, immense reserves of
current and brilliant sonics these designs deliver. At REL, we are commied to constantly--some would say
relentlessly--upgrading our oerings but we always do so in a sensible manner that retains the tried-and-true
while pushing forward in every other aspect of our designs. We trust you will enjoy your new T/i for many
years to come.
Welcome to the REL Family

9 10
REL Serie T/i Rear Panel Connecon Legend
1 Wireless Interface Socket: Used to connect ARROW™ wireless system.
2 Phase: Used to set phase 0-180 degrees.
3 Volume Control for HI/LOW Level input: Use to adjust output when using either HI Level or LOW Level
input. Do not use both simultaneously.
4 Crossover: Used to select crossover frequency. Variable between 30Hz and 120Hz.
5 Low-Level Phono Input: Used to connect low-level to the output of a preamplier, integrated amplier
or receiver. (For home cinema, use .1/LFE input).
6 Volume Control for .1/LFE Input: Use to adjust output level when using .1/LFE input from a 5.1 amplier
or processor.
7 High-Level Neutrik® Speakon® Socket: Use to connect high-level to the main front amplier speaker
terminals.
8 .1/LFE Phono Input: Used to connect to the .1/LFE output from a 5.1 amplier of processor.
9 Power Pilot Light: Power On/O indicator.
10 Power ON/OFF Switch: Use to turn unit on or o.
11 IEC Mains Socket: Fused mains (AC) input socket that accepts a detachable power cord.
8
1
2
3 4
5 6
7
9
10
11

11 12
Always switch o your system before disconnecng any wires.
To increase the versality of connecng up, the SerieT/i models have three separate inputs. A Neutrik®
Speakon® socket and two phono sockets. This is to facilitate use with both two-channel stereo systems and
AV surround sound systems.
The high-level, unbalanced, dual-channel (stereo) input is via a Neutrik® Speakon® connector which is
connected to the power amplier’s le 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 the REL’s Acve Bass Controller (ABC) ensures far superior system integraon of the sub-bass
with the main system.
The low-level input is via two separate phono jacks that connect to either the .1/LFE output of a home
cinema amplier/processor or to the output of a stereo preamplier.
HI LEVEL and .1/LFE inputs can be used simultaneously. The benets are two-fold when used with a home
cinema system. The low level input reproduces the .1/LFE channel and the high level connecon underpins
the main front speakers. The main front speakers should be set to the ‘large’ opon on the processor. See
“Theater Applicaons” for more informaon.
Connecng to the Power Amplier Using the Speakon® High Level Input
To engage the Neutrik® Speakon® plug, insert fully into socket and rotate clockwise unl locked.
To r em ov e th e Ne u tr ik ® S pe ako n® pl ug , g ri p bo dy of p lu g , pl ac e t hu mb o n c hr om e le ve r, m ov e l ev er b ac k wa rd s ,
rotate plug anclockwise quarter turn and withdraw.
The high-level input is designed to accept the stereo (two-channel) signals from the speaker terminals of
your receiver, integrated amplier or basic amplier. This has the advantage of ensuring that your subwoofer
receives exactly the same signal as the main speakers, which means that the character of the bass from the
main system is carried forward into the Sub-Bass System.
This is a very important point and together with REL’s Natural RollO™ circuitry, ensures far superior system
integraon of the Sub-Bass System with the main system.
High-Level Input: Connecons should be made to the same binding post on main amplier as the main
Connecng Up speakers. Red to amplier main right speaker red terminal, yellow to amplier main le speaker red terminal
and black to amplier main speaker black terminal, right or le but not both. Plug the Neutrik® Speakon®
plug into the HI LEVEL Speakon® socket.
.1 Input: This requires a phono-to-phono cable and is a dedicated true .1 channel. This circuit therefore
eliminates the normal Natural RollO™ Crossover and passes the .1 low-level signal through with only the
required 120Hz fourth-order lter.
Low-Level Input: The phono input allows for convenonal connecon from a preamplier and should be
used in the rare event that a high-level connecon proves incompable. Plug one end of the phono-phono
cable into the LOW LEVEL INPUT jack of the REL and the other end into the le or right channel output of
your preamplier.
PHASE SWITCH – Used to set phase
Posion 0 / High-Level, Low-Level or LFE: 0 degrees phase
Posion 180 / High-Level, Low-Level or LFE: 180 degrees phase
PHASE SELECTION AFFECTS BOTH HIGH- AND LOW-LEVEL INPUTS
Crossover is always engaged for Hi level input. The .1/LFE signal does not pass through the crossover circuit.

13 14
REL products are not tradional subwoofers, but true Sub-Bass Systems. A REL is designed to augment the
performance of “full range” speaker systems in order to provide, in certain cases, linear response below 15 Hz.
Therefore, for the moment, please set aside everything you’ve been taught about subwoofers and how they
are integrated into a stereo or home cinema system. REL Sub-Bass Systems set-up and posioning diers
from convenonal subwoofers. A REL will take advantage of physics and room acouscs to provide deep
pressurizaon as no tradional subwoofer can. It is important that you bring to the set-up process a willingness
to do things a lile dierently in order to obtain these superior results. The end result of your labours will
be an uerly seamless integraon of true deep bass to a sound system, regardless of the main speakers’ low
bass capability.
Basic set-up should take no more than ten to een minutes to accomplish once connected.
Two Things Before You Begin
1 It is helpful to know that you will almost always connect the REL to the input on the rear panel labeled
“HIGH LEVEL INPUT.” This connecon is made using the supplied 32’ 10” (10 meters) cable, the bare leads
of which connect to the speaker output terminals of the power amplier. The easy and foolproof connecon
at the REL is done with a Neutrik® Speakon® connector. The purpose of connecng to the speaker output
terminals is one of the unique secrets of REL’s success. By connecng to the High Level input on the REL
from the amplier, you build forward the sonic signature of your main system, including the tonal balance
and ming cues of the enre electronics chain. In this way, the REL is fed the exact signal that is fed to the
main speakers.
2 When possible, the REL should be placed in one of the corners behind the speakers. Remember, we are
dealing with true LOW bass pressurizaon with RELs. Low bass pressurizaon below 40Hz is best derived
from corner placement, where the most linear and ecient low bass can be produced because the
subwoofer is able to take advantage of the tangenal (corner-to-corner) axis which is typically the longest
axis in a room.
Connecng and Seng Up
High-level connecon, using the enclosed cable with the Neutrik® Speakon® connector, is always the rst
choice. This connecon can be made without aecng the performance of the amplier because the REL’s
amplier input impedance is 150,000 ohms, in eect producing NO addional load on the rest of your system.
REL Set-Up Made Simple • The standard high-level hook up procedure is: aach the red wire to the amplier’s right posive speaker
output terminal; aach the yellow wire to the amplier’s le posive speaker output terminal; aach
the black wire to whichever of the amplier’s ground output terminals is convenient; plug the Speakon®
connector into the Sub-Bass System’s high-level input.
• For dierenal (i.e. fully balanced) ampliers using one REL, simply use the standard connecng scheme
with the excepon of NOT connecng the black wire to a negave speaker terminal. Instead, it should
rst be allowed to “oat” or hang down without connecon to ANY terminal. Should hum occur using this
method, please try connecng to an unused RCA connector on the rear of a preamp or amplier. Please
contact your dealer should there be any quesons concerning this or any other hookup procedure.
NOTE: The SerieT/i models are equipped with internal circuitry to allow seamless connecon to Class-D (digital)
ampliers. If connecng to a Class-D amplier, follow the above connecon procedure for dierenal ampliers.
Standard High-level
Dierenal (i.e. Fully Balanced)

15 16
• If connecng RELs to Mono Bloc amplifers we strongly advocate using (2) RELs, one for each amplier.
Connect the black wire of each REL to the negave speaker terminal of the corresponding amplier
channel; twist together the red and yellow wires of each REL separately and connect each pair to the
posive speaker terminal of the corresponding amplier channel. In some instances, this will result in
exceponally 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. If the
amplier is of balanced dierenal design, please follow the instrucons in the secon above
labeled Dierenal Connecon.
Mono Bloc
Mono Bloc Dierenal
• If connecng a single REL as a dedicated center channel sub, please consider connecng to the rear of the
speaker, rather than roung the REL High Level cable all the way back to the amplier. Connect the black
wire of the REL to the negave center channel speaker terminal; twist together the red and yellow wires
and connect this pair to the posive center channel speaker terminal.
• If connecng a REL as a dedicated rear channel sub, connect the black wire of the REL to either the le
rear or right rear negave speaker terminal; connect the yellow wire to the le rear posive speaker
terminal; connect the red wire to the right rear posive speaker terminal. If the amplier is of balanced
dierenal design, please follow the instrucons in the secon above labeled Dierenal Connecon.
Dedicated Rear Channel
Dedicated Center Channel

17 18
Low-level connecon (via phono connectors) is always an opon if high-level connecon is not possible.
When connecng to the low-level inputs in a system in which high-level connecon is not possible, such as
if using internally-amplied speakers, connect le and right phono cables between the LOW LEVEL INPUT
jacks of the REL and the le and right channel outputs of your preamplier.
When connecng to a home cinema system where there is a .1/LFE channel output, connect a single phono
cable between the sub output of the processor/receiver and the .1/LFE input jack on the REL.
1 Posioning: The opmal posion for a REL is in one of the corners behind the main speakers. This posion
provides 9 dB of mechanical amplicaon and allows for the most linear true low bass wave launch, owing
to the ability to tune the REL to the longest distance in the room in order to produce the longest, therefore
lowest, bass waves.
2 The Process: To begin the set-up process, choose a piece of music that has a repeve bass line that is
very low in frequency. We suggest track 4 from the soundtrack to Sneakers (Columbia CK 53146). This has
a repeve bass drum throughout that gives you plenty of me to move the woofer around, but more
importantly, the venue was quite large for this recording, and therefore it has a very deep and large-scale
bass signature. This type of track is perfect for the set-up process and should be played at the highest
reasonable level expected for system playback.
Working with a partner, one in the listening posion and one at the REL manipulang the controls, is the
most eecve and ecient way to set up the REL. If working alone, the inial steps in the set-up can be very
eecvely carried out from the locaon of the REL. Trying to ignore all other music in the track, listen for
the bass drum and its eect on the listening room.
3 Phase Orientaon: Once in the corner we need to adjust for phase. This may be the single most crical step,
and because it really is quite simple, it is oen over-thought. Keep in mind; the right phase is whichever
posion is the loudest or fullest. While playing music with true low bass, adjust the crossover to a point
where the REL and the speaker are sure to share frequencies (about halfway up, or at 12 o’clock on the
crossover control, or slightly higher for smaller speakers). At this point turn the HI/LOW LEVEL control up so
that both the REL and speaker are roughly equal in volume and then switch, using the phase switch, from
“0” to “180” phase posions. Again, whichever posion is loudest or fullest is the correct posion. That is,
when the posion is working in harmony with your main speakers, reinforcing bass, not cancelling it.
4 Placement: The next step is to determine precisely how far from the corner the sub should be placed to
achieve the most ecient output, as well as the lowest frequency extension. With the REL fully into the
corner, and poinng straight out along the diagonal coming out of the corner, connuing to play the music,
slowly pull the REL from the corner on the diagonal, equidistant from both side and rear wall. At a certain
point (somemes a maer of only a few inches, in rare cases a foot or more) the REL will audibly go lower,
play louder, and, if it truly locks on to the room and is fully pressurizing it, the air around the REL will seem
to be energized, stop right there! This is the correct posion from the corner for the REL.
5 Orientaon: Once the posion from the corner has been established, the orientaon of the woofer
must be determined by rotang the REL from an imagined centre point at the rear of the REL. As the REL is
moved from one side to the other listen for the greatest level of output and bass linearity. In eect, the REL
should be le in the posion where it is playing the loudest and lowest.
6 Crossover and Level Sengs: To determine the crossover point, take the volume of the REL (using the
HI/LO Level control) all the way down, and put the crossover to 30 Hz. At this point, bring the REL’s volume
back up slowly to the point where you have achieved a subtle balance, i.e. the point at which you can hear
the REL even with the main speakers playing. Now, bring the crossover point up unl it is obviously too
high; at this point bring it down to the appropriate lower seng. For all intents and purposes, this is the
correct crossover point. Once this stage has been reached, subtle changes to volume and crossover can be
accomplished to provide the last bit of complete and seamless integraon. With that, set-up is complete.
Hint: There may be a tendency to set the crossover point too high and the volume of the Sub-Bass System
too low when rst learning how to integrate a REL with the system, the fear being one of overwhelming the
main speakers with bass. But in doing so, the resulng set-up will be lacking in bass depth and dynamics. The
proper crossover point and volume seng will increase overall dynamics, allow for extended bass frequencies,
and improve soundstage properes. Note, volume must be adjusted in conjuncon with crossover changes.
In general, when selecng a lower crossover point, more volume may need to be applied.

19 20
Theatre Applicaons
For Dolby Digital AC3 or other 5.1 theatre systems, once the standard set-up for two-channel outlined above
is complete, the LFE output from the processor or receiver should be connected to the .1/LFE INPUT and
appropriate volume adjustments made using the .1/LFE level control. For this conguraon, you must set the
processor to the “large” or “full range” seng for the le and right speakers in order for the REL to receive
the bass signal via the high-level cable. In this conguraon, the REL provides support for both the le and
right speakers for two-channel listening, and support for the LFE when movies are playing. Most processors
will allow you to defeat the subwoofer output when listening in the two-channel mode. The eect of this
set-up is one of greatly increased dynamics in the mid-bass range, no bass bloat, and a greater degree of
space and ming from the special audio eects. For an even greater sense of space and impact, a second
REL connected in parallel to the centre channel will prove to be a dramac improvement as well. And if that
is not enough fun, a rear REL, both to support the rear channel speakers as well as to evenly distribute LFE
through the room, truly completes the full-range sonic picture for state-of-the-art lm reproducon.
Running In
Care taken during run in will be rewarded by many years of pleasurable use. Both the electronics and the
drive unit will benet from an inial period of carefully controlled use. Possible damage may be sustained
by running in the unit at too high a volume seng over an extended period. On the other hand, by taking a
lile care over this inial period, about 24 hours of actual use, a longer life with a higher potenal eventual
performance is assured.
Care and Polishing
The cabinets are best maintained by using an automobile polish made by reputable manufacturers. Our
favorites are those made by Meguiars and Mother’s. If objects are to be placed upon the top, it is advisable
to use a small mat to protect the surface and to avoid the risk of rales.
The SerieT/i models use an unusual method of bass loading. They are designed to operate below normal
system resonance. This has been achieved without the normal form of bass boost or electronic equalizaon.
Instead of a constantly increasing bass equalizaon response, we simply ensure there is sucient amplier
gain to drive the speaker unit to its maximum excursion level at whatever the designated lowest operang
frequency is, and then cut the bass at a controlled rate of 12dB per octave above this frequency. Although
this may at rst seem idencal to boosng the bass, it is actually quite dierent and ensures that the ming of
transients is far improved compared to the usual bass equalizaon used. Bass will sound cleaner and faster.
The amplier is fully DC coupled to avoid phase shis and compromises in its low end performance. It is
inherently stable and will retain its characteriscs over very long periods of me – important in a unit
designed for an exceponally long working life. These ampliers are designed to withstand reasonable
abuse and overloads. If in doubt, please contact your dealer.
We believe that the importance of the electronics, cabinet and drivers being designed to work in harmony is
paramount. This approach allows the SerieT/i Sub-Bass Systems to achieve the highest possible level of delity.
Overload Protecon
All REL Sub-Bass Systems are designed as true sub bass speakers. They are designed to reproduce those
exceponally deep notes that are felt as well as heard. This it will aempt to do at whatever volume level you
set. If set too high no damage should result because the built-in electronics will limit the cone movement.
This electronic control is called Set-Safe™. It constantly and instantaneously monitors the output from the
power amplier and is totally transparent in operaon unl required. This means it has absolutely no eect
on the sound quality of your REL unl an overload is detected.
Ordinarily an overload would cause the power amplier to go into clipping with resultant loss of control over
the drive unit. This can cause drive unit damage, and always sounds nasty. Set-Safe™ detects the point of
incipient clipping and gently so-clips the waveform of the signal to ensure actual clipping does not occur.
This is a necessarily simplied descripon of what actually happens, but in eect, Set-Safe™ controls the
amplier and ensures there is minimum risk of amplier and driver damage caused by over-driving.
Technical

21 22
A thermal overload device is ed to all SerieT/i Sub-Bass Systems. If the unit is deliberately overdriven this
device will sense the temperature rise and cut the output; recovery me is approximately ve minutes. If
this happens, it is a warning that the unit is being overdriven and the volume level control should be reduced
to a safe level.
Although everything possible has been done to minimize risk of thermal overload failure, there can be no
defense against those individuals who deliberately abuse the device. Such damage is NOT covered by warranty.
Please remember your REL is there to supplement your main system, not overwhelm it!
Power Saving Eciency
All REL sub bass system designs ulize a true On-O switch that aords the owner the ability to turn o
their unit completely, without having to unplug the A/C mains cord. When a REL sub bass system is switched
o using the On-O switch on the rear panel it draws ZERO power.
It is not necessary to switch your SerieT/i o between listening sessions- it will not signicantly shorten its
life by leaving it switched on. On the other hand, it will not harm sound quality if it is always switched o.
It is perfectly safe to leave your SerieT/i on under all normal domesc circumstances as it is fully protected
by internal fuses and an external mains fuse in the mains input socket. There is a spare fuse inside the
input socket.
T/9i Specicaons
Type: Passive Radiator, front-ring acve woofer, down-ring passive radiator
Acve Drive Unit: 10in., 254 mm long-throw, inverted dust cap, steel chassis
Passive Radiator: 10in., 254 mm
Lower Frequency Response: 28 Hz at -6 dB in room
Input Connectors: Hi Level Neutrik Speakon, Lo Level single phono, LFE phono
Input Impedance: High Level: 150kΩ, Low Level: 10kΩ, .1/LFE: 10kΩ
Gain Control Range: 80 dB
Power Output: 300 Was (RMS)
Phase Switch: Yes, 0 or 180 degrees
Amplier Type: Class AB
Wireless Capability: Yes - REL Arrow™ wireless system [required], Sold separately
Protecon System
Fully Electronic SET-SAFE: Yes
D.C. Fault: Yes
Output Short: Yes
Mains Input Voltage: 220-240 volts, 110-120 volts for certain markets
Fuses: 3.15 Amp semi delay 230 volts operaon
6.3 Amp semi delay 115 volts operaon
Dimensions (WHD): Including Feet and Rear Panel Controls
13 x 15.2 x 16 in., (330 x 387 x 407 mm)
Add 1.75 in (44.5 mm) in depth when using Hi Level connector
Net Weight: 41.3 lbs. (18.7 kg)
Finish: Gloss Piano Black or White Lacquer
Supplied Accessories
Mains Lead: Yes
Neutrik Speakon Interconnect: Yes (10 Meters Nominal)
Users Manual: Yes

2423
T/7i Specicaons
Type: Passive Radiator, front-ring acve woofer, down-ring passive radiator
Acve Drive Unit: 8in., 200 mm long-throw, inverted dust cap, steel chassis
Passive Radiator: 10in., 254 mm
Lower Frequency Response: 30 Hz at -6 dB in room
Input Connectors: Hi Level Neutrik Speakon, Lo Level single phono, LFE phono
Input Impedance: High Level: 150kΩ, Low Level: 10kΩ, .1/LFE: 10kΩ
Gain Control Range: 80 dB
Power Output: 200 Was (RMS)
Phase Switch: Yes, 0 or 180 degrees
Amplier Type: Class AB
Wireless Capability: Yes - REL Arrow™ wireless system [required], Sold separately
Protecon System
Fully Electronic SET-SAFE: Yes
D.C. Fault: Yes
Output Short: Yes
Mains Input Voltage: 220-240 volts, 110-120 volts for certain markets
Fuses: 2 Amp semi delay 230 volts operaon
4 Amp semi delay 115 volts operaon
Dimensions (WHD): Including Feet and Rear Panel Controls
12 x 14.3 x 15 in., (305 x 362 x 382 mm)
Add 1.75 in (44.5 mm) in depth when using Hi Level connector
Net Weight: 36 lbs. (16.3 kg)
Finish: Gloss Piano Black or White Lacquer
Supplied Accessories
Mains Lead: Yes
Neutrik Speakon Interconnect: Yes (10 Meters Nominal)
Users Manual: Yes
T/5i Specicaons
Type: Closed Box, down-ring acve woofer
Acve Drive Unit: 8in., 200 mm long-throw, inverted dust cap, steel chassis
Lower Frequency Response: 32 Hz at -6 dB in room
Input Connectors: Hi Level Neutrik Speakon, Lo Level single phono, LFE phono
Input Impedance: High Level: 150kΩ, Low Level: 10kΩ, .1/LFE: 10kΩ
Gain Control Range: 80 dB
Power Output: 125 Was (RMS)
Phase Switch: Yes, 0 or 180 degrees
Amplier Type: Class AB
Wireless Capability: Yes - REL Arrow™ wireless system [required], Sold separately
Protecon System
Fully Electronic SET-SAFE: Yes
D.C. Fault: Yes
Output Short: Yes
Mains Input Voltage: 220-240 volts, 110-120 volts for certain markets
Fuses: 1.6 Amp semi delay 230 volts operaon
3.15 Amp semi delay 115 volts operaon
Dimensions (WHD): Including Feet and Rear Panel Controls
10.5 x 12.5 x 12.7 in., (267 x 317 x 322 mm)
Add 1.75 in (44.5 mm) in depth when using Hi Level connector
Net Weight: 26.5 lbs. (12 kg)
Finish: Gloss Piano Black or White Lacquer
Supplied Accessories
Mains Lead: Yes
Neutrik Speakon Interconnect: Yes (10 Meters Nominal)
Users Manual: Yes
In the interest of product development, REL Acouscs Limited reserve the right to vary these specicaons without noce.

25 26
Notes