REL HT/MKII User manual

Operang Instrucons for the
HT/MKII
Sub-Bass
System
2

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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.

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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 storms 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.
Important Safety Instrucons

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15 Minimum distances 10cm around the apparatus for sucient venlaon.
16 WARNING: The main plug/appliance coupler is used as the disconnect device. The disconnect device
shall remain readily operable.
17 CAUTION: To completely disconnect this product from the mains, disconnect the plug from the wall
socket outlet. The mains plug is used to completely interrupt the power supply to the unit and must be
within easy access by the user.
18 The equipment can be used at the maximum ambient temperature of 86 deg. F (30 deg. C).
19 Class I equipment, Protecve earthing is used as a safeguard, shall require connecon of equipment
protecve earthing conductor to the installaon protecve earthing conductor.
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.
Warning
To reduce the risk of re or electric shock, do not expose this apparatus to rain or moisture.
The apparatus shall not be exposed to dripping or splashing and no objects lled with liquids, such as vases,
shall be placed on apparatus.
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.
Design Safety
These apparatus are supplied with a detachable mains cord. For 230V operaon a 2.5A fuse is ed in the
socket of the HT/1003 MKII and a 5A fuse is ed in the socket of the HT/1205 MKII, for 120V operaon a
4A fuse is ed for the HT/1003 MKII, and a 8A fuse is ed for the HT/1205 MKII. 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.

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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).
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.
Informaons Importantes Relaves a la Securite

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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.
15 10cm distance minimale autour de l’appareil pour une aéraon susante.
16 AVERTISSEMENT: Le coupleur principal de prise/appareil est ulisé comme disposif de déconnexion.
Le disposif de déconnexion doit rester facilement ulisable.
17 ATTENTION: Pour déconnecter complètement ce produit du secteur, débranchez la che de la prise
murale. La che secteur sert à interrompre complètement l’alimentaon électrique de l’appareil et doit
être facilement accessible par l’ulisateur.
18 L’équipement peut être ulisé à une température ambiante maximale de 30 deg. C (86 deg. F).
19 L’équipement de classe I, la mise à la terre de protecon est ulisée comme protecon, doit nécessiter
la connexion du conducteur de mise à la terre de protecon de l’équipement au conducteur de mise à la
terre de protecon de l’installaon.
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.

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Averssement
Cet arcle est lourd. Pour éviter tout risque de blessure, prendre soin lors de la manipulaon.
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.
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.
Sécurité Design
Ces appareils sont fournis avec un cordon d’alimentaon amovible. Pour un fonconnement en 230 V, un
fusible de 2,5 A est installé dans la prise du HT/1003 MKII et un fusible de 5 A est installé dans la prise du
HT/1205 MKII, pour un fonconnement en 120 V, un fusible de 4 A est installé pour le HT/1003 MKII et un
fusible de 8 A est adapté pour le HT/1205 MKII. Si le fusible doit être remplacé, ulisez un fusible de calibre
similaire approuvé selon les normes ASTA ou BSI 362. Ne pas uliser sans le couvercle du fusible en place.
Des couvre-fusibles de remplacement 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.

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Consult the dealer or an experienced radio/TV technician for help.
Dear REL Owner,
REL are incredibly excited about these newer HT models. Whilst the originals were exceponally well-received
by reviewers and customers alike, we had learned so much from our development of the latest Serie S and
Serie T/x models that we felt certain we could eect real improvements if we applied some of these to our HT’s.
WOW! The improvements turned out to be truly remarkable. Drivers, amps and lters were upgraded
across the line. The result delivers far higher output levels, greater dynamics (the dierence between loud
and so) a more relaxed, composed presence like much more expensive units deliver and a huge upgrade
in style, design and t and nish.
The nal touch is that these are far beer developed for music applicaons than were the originals. And
they visually integrate perfectly with tradional RELs in HT/3D applicaons.
HT/1205 MKII meanwhile beneed from a full 6 dB (50% louder) increase in output taking this into the realm
of units cosng well over $1,000/£. Incredible output, delivered with greater explosiveness on special eects,
but beer able to deal with musical material means a unit that has evolved signicantly for the beer.
And then there’s the lile HT/1003 MKII; sporng a 10+ dB increase in output with all the same benets
that aach to our dearer models it is the most dramacally updated. It no longer represents the lile
brother; rather it is idencal in quality to our best-selling HT/1205 MKII in a smaller chassis that will allow it
to t where larger models can’t.
Thank You and Enjoy, we grew to love this new range as it evolved before our eyes and ears.
Best, J
John Hunter
Lead Designer,
REL Acouscs Limited
Dear Friend and Valued Customer

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1 Power Pilot Light: Power On/O indicator.
2 Standby/ Always On Switch: Used to enable standby mode
3 Phase: Used to set phase 0-180 degrees.
4 Crossover: Used to adjust crossover frequency. Variable between 30-200Hz.
5 Level: Volume control for Input.
6 RCA Output: Used to connect or “daisy chain” another REL in tandem.
7 Le & Right Channel Low-Level RCA Input: Used to connect low-level signals to the sub-bass system
from the output of a preamplier, integrated amplier or receiver.
(For home cinema use, use .1/LFE input)
8 Mains Select Switch: Slide switch used to set input AC between 120VAC and 230VAC.
9 Power On/O Switch: Use to turn unit on or o.
10 IEC Mains Socket: Fused mains (AC) input socket that accepts detachable power cord.
REL HT/MKII Rear Panel Connecon Legend

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8 9 10
1
2
3
4
5
6
7

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Always switch o your system before disconnecng any wires.
To simplify and to increase the versality of connecng, the HT/MKII models have two low-level RCA
inputs. This is to facilitate ability to use with AV surround sound systems, two-channel stereo systems and
powered speakers.
Low-Level Inputs
.1/LFE Input
There is a single RCA jack labeled .1/LFE for LFE connecon to a processor. Plug one end of the RCA to RCA
cable into the .1/LFE jack of the REL and the other end into the SUB OUT Jack of your processor.
Stereo L/R Input
The dual RCA jacks can be used for stereo low-level connecon to the output of a stereo processor source or
powered speakers. When using stereo inputs, plug one end of the RCA to RCA cables into both of the LOW
LEVEL INPUT jacks of the REL and the other end into the le and right channel output of your preamplier.
The upper frequency amplicaon of these inputs can be limited using the CROSSOVER control. This
CROSSOVER control is labeled 30Hz at its minimum. Rarely should the CROSSOVER control be set to it’s
maximum 200Hz setpoint when using either LFE or stereo inputs.
The RCA inputs have corresponding output connecons so that mulple RELs can be run in parallel by
connecng the OUT of one the IN of the next. This is what we refer to as “daisy chaining”.
Phase Switch
The phase control on a REL has two posions, 0 and 180. One of these posions will set the REL in phase
with the speakers, and one will set it out of phase. The labels 0 and 180 are just labels and tell us nothing
about the rest of the system, only if the REL is working with the speakers or not. Whichever posion results
in the loudest and fullest sub bass, is the correct posion.
We want the REL to work in harmony with the speakers, reinforcing bass, not cancelling it. In other words,
we want the drivers in the speakers and the REL to move forward at the same me and move backward at
the same me. When this happens, it results in an increase in sub bass volume and the pressurizaon in the
room and they are in phase. The opposite is if the speakers and REL are working against each other causing
cancelaon of low bass. We call this out of phase.
Connecng Up

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With the REL HT/MKII, there are two basic ways to connect and setup. The rst is a single channel input
from the sub out of a theater or power speaker system. In this case a single RCA cable is needed. The second
is a stereo input from a stereo preamp or powered speaker system. Here there will be the need for two RCA
cables. In both cases the user can set the upper frequency limit using the CROSSOVER control.
Connecng and Seng Up
Place in desired posion. While your REL has been designed to be extremely easy to posion and achieve
excellent results, careful placement along the same wall as the screen will yield improvements. Listen for
increases in deep bass output as well as precision of bass notes when seng up.
Theater connecon (Sub Out connecton)
Connect RCA cable from Sub Out of theater processor to LFE input of HT/MKII.
• Adjust CROSSOVER control to 30Hz (minimum).
• Adjust LEVEL control to 1/4 of the rotaon up from minimum seng.
• Plug in AC cord.
• Power on with switch next to AC input.
• Set toggle above power switch to ALWAYS ON.
• Fine tune LEVEL control using a known powerful .1 chapter to make sure your seng is not too high or
damage can occur.
• Adjust CROSSOVER control lower to eliminate upper bass boom.
• DO NOT TURN CROSSOVER UP PAST 1/2 the rotaon. Doing so is unnecessary and may result in damage
to the driver.
REL Set-Up Made Simple

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Stereo connecon (Powered Speaker connecon)
Connect RCA from output to right input for mono or both le and right for stereo.
• Adjust CROSSOVER control to 30Hz (minimum).
• Adjust LEVEL control to 1/4 of the rotaon up from minimum seng.
• Plug in AC cord.
• Power on with switch next to AC input.
• Set toggle above power switch to ALWAYS ON.
• Fine tune LEVEL control to blend with powered speakers.
• Fine tune CROSSOVER control to blend.
• Note that CROSSOVER and LEVEL become inverse. Meaning, as you turn up the CROSSOVER, you will
need to turn down the LEVEL.
• DO NOT TURN CROSSOVER UP PAST 1/2 the rotaon. Doing so is unnecessary and may result in
damage to the driver.
• Place carefully: While your REL has been designed to be extremely easy to posion and achieve
excellent results, careful placement along the same wall as the screen will yield improvements.
Listen for increases in deep bass output as well as precision of bass notes when seng up
Phase Orientaon
Once connected, 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 at 50Hz on the crossover control, or slightly higher for smaller speakers. At
this point turn the LEVEL control up so that both the REL and speaker are roughly equal in volume and then

14
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 canceling it.
Crossover and Level Sengs:
To determine the crossover point, take the volume of the REL (using the Level control) all the way down,
and put the crossover to 1/4 of the rotaon. 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 just hear the HT/MKII even
with the main speakers playing. First, bring the crossover point up unl it is obviously too high; now gently
reduce frequency to the appropriate 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 may 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. In making this common error, 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 adjustments may need to be made to
oset the eects of crossover changes. In general, when selecng a lower crossover point, more volume may
need to be applied. Higher crossover frequencies will generally necessitate less gain
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 only a damp cloth on the vinyl. For the top, please use
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 HT/MKII employs an advanced lter circuit which provides exceponal performance when coupled to
the rest of the signal chain of the Sub-Bass System.
The amplier 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 belief allows HT/MKII 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.
A thermal overload device is ed to all HT/MKII Sub-Bass Systems. If the unit is deliberately over-driven
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 over-driven 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!
15
Technical

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Power Saving Eciency
All REL Sub-Bass System designs ulize a true Power 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 Power On-O switch on the rear panel it draws ZERO power.
In addion to the power switch there is an ALWAYS ON/STANDBY mode switch that has two posions.
Up engages the STANDBY circuit and down keeps the unit always on. In addion to the power switch there
is an ALWAYS ON/STANDBY mode switch has two posions. Up engages the STANDBY circuit and down keeps
the unit always on.
The HT/MKII features a standby mode that is enabled when the mode switch on the rear of the unit is set to
the “STANDBY” posion. In this mode, the input signal is constantly monitored for audio acvity. If not audio
informaon is detected over a period of 30 minutes, the unit will enter a low power standby mode in which
less power is consumed. When input signal acvity is detected, the unit resumes normal operaon. By using
the standby mode, you can ensure that there is no unnecessary power draw when the unit is not in use.
Note: Due to variaons in program material, it is impossible to produce a perfectly reliable standby circuit.
Bass rich music or eects will consistently trigger our standby circuit whilst content that is low in volume and
possesses lile or no bass cannot be relied upon to trip the standby funcon.
Alternavely, the user has the opon to leave the unit in the normal operaon mode at all mes by selecng
the “ALWAYS ON” posion of the power mode switch. Leaving a REL on produces the best sonic performance
and the most reliable operaon. In this mode, the unit will not enter standby regardless of whether or not
there is acvity at the input. Using this seng ensures that the HT/MKII is ready to react instantaneously to
bass transients, whether in music or lms.
Model Power Draw at Standby Power Draw at Idle
HT/1205 MKII > 0.5 Was 13 Was
HT/1003 MKII > 0.5 Was 10 Was

Type: Closed box, front ring woofer
Drive Unit: 12 in., carbon ber reinforced cone with inverted carbon ber center cap
In Room
Frequency Extension: -6dB at 22Hz in Room
Input Connectors: Low Level stereo RCA, LFE RCA
Output Connectors: Low Level stereo RCA, LFE RCA
Power Output: 500 was (RMS)
Phase Switch: 2 - posion, 0 or 180 degrees
Amplier Type: Class D
Fully Electronic with SET-SAFE: Yes
DC Fault: Yes
Output Short: Yes
Mains Input Voltage: 220-240 volts, 110-120 volts for certain markets
Fuses: 4 Amp semi delay 230V operaon
8 Amp semi delay 115V operaon
Dimensions
W x H x D, Inc. Feet: Including feet and rear panel controls
16.25 x 15.25 x 17.25 in., (413 x 387 x 438 mm)
Net Weight: 43.2 lbs. (19.6 kg)
Shipping Weight: 51 lbs. (23 kg)
Finish: Horizontally Oriented Line Grained Composite,
15 mm Top Plate, nished in 5 coats of hand-rubbed high gloss lacquer
Supplied Accessories
Mains Lead: Included
Users Setup guide: Online
17
HT/1205 MKII Specicaons

Type: Closed box, front ring woofer
Drive Unit: 10 in., carbon ber reinforced cone with inverted carbon ber center cap
In Room
Frequency Extension: -6dB at 24Hz in Room
Input Connectors: Low Level stereo RCA, LFE RCA
Output Connectors: Low Level stereo RCA, LFE RCA
Power Output: 300 was (RMS)
Phase Switch: 2 - posion, 0 or 180 degrees
Amplier Type: Class D
Fully Electronic with SET-SAFE: Yes
DC Fault: Yes
Output Short: Yes
Mains Input Voltage: 220-240 volts, 110-120 volts for certain markets
Fuses: 2.5 Amp semi delay 230V operaon
5 Amp semi delay 115V operaon
Dimensions
W x H x D, Inc. Feet: Including feet and rear panel controls
14.25 x 13.25 x 15.25 in., (362 x 343 x 387 mm)
Net Weight: 34.2 lbs. (15.5 kg)
Shipping Weight: 41 lbs. (18.6 kg)
Finish: Horizontally Oriented Line Grained Composite,
15 mm Top Plate, nished in 5 coats of hand-rubbed high gloss lacquer
Supplied Accessories
Mains Lead: Included
Users Setup guide: Online
In the interest of product development, REL Acouscs Limited reserve the right to vary these specicaons without noce
18
HT/1003 MKII Specicaons

REL Acouscs Limited
North Road, Bridgend industrial Estate . Bridgend, CF31 3TP . United Kingdom
Telephone: [phone] . Fax: [phone]
Web: www.rel.net