REL HT/MKII Sub Bass System User Manual
- July 30, 2024
- REL
Table of Contents
REL HT/MKII Sub Bass System
Product Usage Instructions
- Read all provided instructions carefully.
- Keep the instructions for future reference.
- Adhere to all warnings and instructions provided.
- Avoid using the apparatus near water sources.
- Use automotive polish and microfiber cloth for cleaning.
- Follow the manufacturer’s installation guidelines.
- Avoid placing near heat sources.
- Do not modify the grounding-type plug.
- Unplug during lightning storms or prolonged periods of non-use.
- Refer servicing to qualified personnel if the apparatus is damaged or malfunctions.
- Maintain at least 10cm of space around the apparatus for proper ventilation.
- Ensure the main plug/appliance coupler is easily accessible for disconnection.
- To disconnect the product from the mains, unplug from the wall socket outlet.
- Avoid operating the equipment above 86 deg. F (30 deg. C).
FAQ
- What should I do if my HT/MKII Sub-Bass System malfunctions?
- If your system malfunctions, immediately unplug it and refer servicing to qualified personnel. Do not attempt to repair the system yourself.
- Can I clean the HT/MKII Sub-Bass System with regular household cleaners?
- No, it is recommended to clean the system only with automotive polish and a microfiber cloth to avoid damage.
CAUTION
- The lightning flash with the 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 sufficient magnitude to constitute a risk of electric shock to persons.
- The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance.
Important Safety Instructions
- Read all of these instructions.
- Save these instructions for future use.
- Heed all warnings.
- Follow all instructions.
- Do not use this apparatus near water.
- Clean only with automotive polish and microfiber cloth.
- Install by the manufacturer’s instructions.
- Do not install near any heat sources such as radiators, heat registers, stoves or other apparatus (including amplifiers) that produce heat.
- 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 fit into your outlet, consult an electrician for the replacement of the obsolete outlet.
- Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
- Only use attachments/accessories specified by the manufacturer.
- Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
- Unplug this apparatus during lightning storms or when unused for long periods.
- Refer all servicing to qualified 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.
- Minimum distances 10cm around the apparatus for sufficient ventilation.
- WARNING: The main plug/appliance coupler is used as the disconnect device. The disconnect device shall remain readily operable.
- 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.
- The equipment can be used at the maximum ambient temperature of 86 deg. F (30 deg. C).
- Class I equipment, Protective earthing is used as a safeguard, shall require connection of equipment protective earthing conductor to the installation protective earthing conductor.
Caution: Any changes or modifications 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 fire 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 filled with liquids, such as vases, shall be placed on the apparatus.
- The mains plug is used as a 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 be disconnected from the mains.
- An appliance with a protective earth terminal should be connected to a mains outlet with a protective earth connection.
Design Safety
These apparatus are supplied with a detachable mains cord. For 230V operation,
a 2.5A fuse is fitted in the socket of the HT/1003 MKII and a 5A fuse is
fitted in the socket of the HT/1205 MKII, for 120V operation a 4A fuse is
fitted for the HT/1003 MKII, and a 8A fuse is fitted 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.
FCC STATEMENT
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
- This device may not cause harmful interference, and
- This device must accept any interference received, including interference that may cause undesired operation.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, according to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation.
This equipment generates, uses, and can radiate radio frequency energy and, if
not installed and used per the instructions, may cause harmful interference to
radio communications. However, there is no guarantee that the interference
will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined
by turning the equipment off 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 separation between the equipment and the receiver.
Connect the equipment to an outlet on a circuit different from that to which
the receiver is connected.
Dear Friend and Valued Customer
Dear REL Owner,
REL are incredibly excited about these newer HT models. Whilst the originals
were exceptionally 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 effect real improvements if we applied
some of these to our HT’s. WOW! The improvements turned out to be truly
remarkable. Drivers, amps and filters were upgraded across the line. The
result delivers far higher output levels, greater dynamics (the difference
between loud and soft) a more relaxed, composed presence like much more
expensive units deliver and a huge upgrade in style, design and fit, and
finish.
The final touch is that these are far better developed for music applications
than were the originals. And they visually integrate perfectly with
traditional RELs in HT/3D applications.
HT/1205 MKII meanwhile benefitted from a full 6 dB (50% louder) increase in
output taking this into the realm of units costing well over $1,000/£.
Incredible output, delivered with greater explosiveness on special effects,
but better able to deal with musical material means a unit that has evolved
significantly for the better.
And then there’s the little HT/1003 MKII; sporting a 10+ dB increase in output
with all the same benefits that attach to our dearer models it is the most
dramatically updated. It no longer represents the little brother; rather it is
identical in quality to our best-selling HT/1205 MKII in a smaller chassis
that will allow it to fit 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 Acoustics Limited
Rear Panel Connection
REL HT/MKII Rear Panel Connection Legend
-
Power Pilot Light: Power On/Off indicator.
-
Standby/ Always On Switch: Used to enable standby mode
-
Phase: Used to set phase 0-180 degrees.
-
Crossover: Used to adjust crossover frequency. Variable between 30-200Hz.
-
Level: Volume control for Input.
-
RCA Output: Used to connect or “daisy chain” another REL in tandem.
-
Left & Right Channel Low-Level RCA Input: Used to connect low-level signals to the sub-bass system from the output of a preamplifier, integrated amplifier or receiver.
(For home cinema use, use .1/LFE input) -
Mains Select Switch: The slide switch is used to set input AC between 120VAC and 230VAC.
-
Power On/Off Switch: Use to turn the unit on or off.
-
IEC Mains Socket: Fused mains (AC) input socket that accepts a detachable power cord.
Connecting Up
- Always switch off your system before disconnecting any wires.
- To simplify and to increase the versatility of connecting, the HT/MKII models have two low-level RCA inputs.
- This is to facilitate the ability to use 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 connection 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 connection 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 left and right channel output of your
preamplifier.
The upper-frequency amplification 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 connections so that multiple RELs can
be run in parallel by connecting the OUT of one to the IN of the next. This is
what we refer to as “daisy chaining”.
Phase Switch
The phase control on a REL has two positions, 0 and 180. One of these
positions 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 position results in the loudest and fullest sub-bass is correct.
We want the REL to work in harmony with the speakers, reinforcing bass, not
canceling it. In other words, we want the drivers in the speakers and the REL
to move forward and backward at the same time. When this happens, it results
in an increase in sub-bass volume and the pressurization in the room and they
are in phase. The opposite is if the speakers and REL are working against each
other causing cancelation of low bass. We call this out of phase.
REL Set-Up Made Simple
With the REL HT/MKII, there are two basic ways to connect and set up. The first 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.
Connecting and Setting Up
Place in the desired position. While your REL has been designed to be
extremely easy to position 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 setting
up.
Theater connection (Sub Out connecton)
Connect the RCA cable from the sub-out-of-theater processor to the LFE input
of HT/MKII.
- Adjust CROSSOVER control to 30Hz (minimum).
- Adjust LEVEL control to 1/4 of the rotation up from the minimum setting.
- Plug in AC cord.
- Power on with the switch next to AC input.
- Set the toggle above the power switch to ALWAYS ON.
- Fine-tune LEVEL control using a known powerful .1 chapter to make sure your setting is not too high or damage can occur.
- Adjust the CROSSOVER control lower to eliminate the upper bass boom.
- DO NOT TURN CROSSOVER UP PAST 1/2 the rotation. Doing so is unnecessary and may result in damage to the driver.
Stereo connection (Powered Speaker connection)
Connect RCA from output to right input for mono or both left and right for
stereo.
- Adjust CROSSOVER control to 30Hz (minimum).
- Adjust LEVEL control to 1/4 of the rotation up from the minimum setting.
- Plug in AC cord.
- Power on with the switch next to the AC input.
- Set the toggle above the 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 rotation. 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 position 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 setting up
Phase Orientation
Once connected, we need to adjust for phase. This may be the single most
critical step, and because it is quite simple, it is often over-thought. Keep
in mind; that the right phase is whichever position 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 switch, using the phase switch, from “0” to
“180” phase positions. Again, whichever position is loudest or fullest is the
correct position. That is, when the position is working in harmony with your
main speakers, reinforcing bass, not canceling it.
Crossover and Level Settings:
To determine the crossover point, take the volume of the REL (using the Level
control) down, and put the crossover to 1/4 of the rotation. 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 until it
is too high; now gently reduce frequency to the appropriate setting. 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 integration. With that, setup 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 first 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 resulting set-up will be lacking in
bass depth and dynamics. The proper crossover point and volume setting will
increase overall dynamics, allow for extended
bass frequencies, and improve soundstage properties. Note, volume adjustments
may need to be made to offset the effects of crossover changes. In general,
when selecting a lower crossover point, more volume may need to be applied.
Higher crossover frequencies will generally necessitate less gain
Running In
The care taken during the run-in will be rewarded by many years of pleasurable
use. Both the electronics and the drive unit will benefit from an initial
period of carefully controlled use. Possible damage may be sustained by
running in the unit at too high a volume setting over an extended period. On
the other hand, by taking a little care over this initial period, about 24
hours of actual use, a longer life with a higher potential 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
on the top, it is advisable to use a small mat to protect the surface and to
avoid the risk of rattles.
Technical
- The HT/MKII employs an advanced filter circuit which provides exceptional performance when coupled to the rest of the signal chain of the Sub-Bass System.
- The amplifier is inherently stable and will retain its characteristics over very long periods – important in a unit designed for an exceptionally long working life. These amplifiers 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 fidelity.
Overload Protection
All REL Sub-Bass Systems are designed as true sub-bass speakers. They are
designed to reproduce those exceptionally deep notes that are felt as well as
heard. This it will attempt 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 amplifier and is transparent in operation
until required. This means it does not affect the sound quality of your REL
until an overload is detected.
Ordinarily, an overload would cause the power amplifier to go into clipping
with a 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 soft-clips the waveform of the signal to ensure actual
clipping does not occur.
This is a necessarily simplified description of what happens, but in effect,
Set-Safe™ controls the amplifier and ensures there is minimum risk of the
amplifier and driver damage caused by over-driving.
A thermal overload device is fitted 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 time is approximately five 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 the 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 Efficiency
- All REL Sub-Bass System designs utilize a true Power On-Off switch that affords the owner the ability to turn off their unit completely, without having to unplug the A/C mains cord. When a REL Sub-Bass System is switched off using the Power On-Off switch on the rear panel it draws ZERO power.
- In addition to the power switch, there is an ALWAYS ON/STANDBY mode switch that has two positions.
- Up engages the STANDBY circuit and down keeps the unit always on. In addition to the power switch, there is an ALWAYS ON/STANDBY mode switch that has two positions. 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” position. In this mode, the input signal is constantly monitored for audio activity. If no audio information is detected for 30 minutes, the unit will enter a low-power standby mode in which less power is consumed. When input signal activity is detected, the unit resumes normal operation.
- 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 variations in program material, it is impossible to produce a perfectly reliable standby circuit.
- Bass-rich music or effects will consistently trigger our standby circuit whilst content that is low in volume and possesses little or no bass cannot be relied upon to trip the standby function.
- Alternatively, the user has the option to leave the unit in the normal operation mode at all times by selecting the “ALWAYS ON” position of the power mode switch. Leaving a REL on produces the best sonic performance and the most reliable operation. In this mode, the unit will not enter standby regardless of whether or not there is activity at the input. Using this setting ensures that the HT/MKII is ready to react instantaneously to bass transients, whether in music or films.
Specifications
HT/1205 MKII Specifications
- Type: Closed box, front-firing woofer
- Drive Unit: 12 in., carbon fiber reinforced cone with inverted carbon fiber 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 watts (RMS)
- Phase Switch: 2 – position, 0 or 180 degrees
- Amplifier 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 operation 8 Amp semi delay 115V operation
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, finished in 5 coats of hand-rubbed high gloss lacquer
Supplied Accessories
- Mains Lead: Included
- Users Setup guide: Online
HT/1003 MKII Specifications
- Type: Closed box, front firing woofer
- Drive Unit: 10 in., carbon fiber reinforced cone with inverted carbon fiber 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 watts (RMS)
- Phase Switch: 2 – position, 0 or 180 degrees
- Amplifier 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 operation 5 Amp semi-delay 115V operation
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: Black or White Horizontally Oriented Line Grained Composite, 15mm Top Plate, finished in 5 coats of hand-rubbed high gloss lacquer
Supplied Accessories
- Mains Lead: Included
- Users Setup guide: Online
CONTACT
REL Acoustics Limited
- North Road, Bridgend Industrial Estate. Bridgend, CF31 3TP. United Kingdom
- Telephone: +44 (0)1 656 768 777. Fax: +44 (0) 1 656 766 093
- Web: www.rel.net
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>