REL Strata II User manual

REL
Operating Instructions
for the
Strata II
Sub-Bass System
REL Acoustics Ltd
North Road, Bridgend Industrial Estate,
Bridgend, Mid Glamorgan, CF31 3TP.
United Kingdom.
Telephone: [phone]; International: [phone]
Fax: [phone] International: [phone]

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WELCOME
Thank you for buying the REL STRATA II Sub-Bass system STRATA II has been
carefully hand crafted from the finest materials available and we are sure that it will
give you many years of listening pleasure. This manual contains important safety
information as well as helpful advice and should be carefully studied before
connecting up.
World Wide Warranty
In addition to any local Warranty, REL offer a 3-year conditional Worldwide
Warranty to the end user. It is done in collaboration with our Distributors.
The conditions of this Warranty are:
1. That REL receive the necessary registration details from the end user.
2. That these details are received within six weeks of purchase.
3. That the product is not exported from the country of purchase for at least eight
weeks after purchase.
4. That any claim is accompanied by the necessary proof of purchase.
5. That it shall be for a term of 3 years from the date of purchase.
6. That the product has not been abused or modified in any way.
This Warranty is offered in good faith and is in addition to any statuary rights or
existing Warranty that may be available to the end user.
Should your STRATA II unit give you a problem, please contact your Dealer who will
be able to make whatever arrangements are necessary to correct it.
SERVICE AFTER WARRANTY
Please contact your Dealer in the first instance before returning any product direct to
us. Should the unit need to be returned for any reason, all carriage costs will be
payable by the Customer. Losses or damage caused during transit are the
Customer's risk.
WARNING
This item is heavy! To avoid risk of injury, take care when handling.
CONNECTING UP

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Always switch off your system before disconnecting any wires
Screw the spikes into the steel inserts already fitted into the feet of the sub-woofer.
Level them up compensating for an uneven floor if necessary. It is not essential nor
is it desirable to over-tighter these spikes. Use the lock-nut to ensure that the spike
cannot work loose.
There are two entirely separate methods of connecting your Strata II to your system.
1. To Connect To The Power Amplifier ( See Fig. 1 )
This method uses the signal at the loudspeaker outputs on your power amplifier. If
you choose this method, your existing speaker wires can be twisted together with
the Neutrik Speakon signal interconnect supplied with Strata II and connected to
your existing speaker plugs, or connect the Strata II lead to a spare set of speaker
terminals. In effect, Strata II is bi-wired from your power amplifier. However, note
that there are only three connections to Strata II. This is deliberate and helps
preserve the existing star earthing of you system (assuming it has a star earth
arrangement).
R/H L/H
Amplifier Speaker
Outputs
Red Yellow Neutrik Speakon
Interconnect (Supplied)
Black ToStrata2
High Level Input
Fig. 1
Remove the speaker leads to your main speakers (front left and front right with a
surround sound system) from your amplifier and twist the RED coloured wire from
the REL interconnect together with the RED wire of the right hand speaker. Twist
the YELLOW coloured wire of the REL interconnect with the RED wire of the left
hand speaker. The single BLACK wire of the REL interconnect is connected to
either one (but NOT both) of the wires that is connected to one of the BLACK
speaker terminals. Now reconnect your speaker wires back onto their correct
speaker terminals, taking great care that there are no loose wires that could touch
and cause a short circuit. Only after you are satisfied that everything is connected
correctly should you then switch your equipment back on.
Note:- Subwoofer outputs are often now referred to as LFE (Low Frequency
Effect) outputs
2. To Connect To A Dedicated Sub-Woofer (LFE) Output Or Preamp Output
( See Figs. 2 and 3 )
R B R B

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The alternative method of connecting Strata II is by using its phono sockets. (A
phono to phono interconnect is available from your dealer if required). Either one or
both phono plugs can be connected to your system's LFE (Low Frequency Effect)
output (if fitted) Fig. 2, or to your television's headphone audio output socket, or it
can be connected to a spare pair of preamp output sockets Fig. 3. With this
method, provided you have a separate preamp and power amplifier, you have the
option of routing your preamp's output through the Strata II. This will cut the bass to
your main speakers. This is recommended only where maximum sound volume
must take precedence over overall sound quality To take advantage of this option
simply feed your preamp output to the Strata II and then use one of the pairs of
output phonos on Strata II to feed your power amplifier. This can have some
advantage concerning the maximum power handling capability, but has the
disadvantage of affecting main signal purity. It is impossible to predict which pair of
output phonos on Strata II will give the best overall compromise of sound. This is
only recommended where the power handling of the main speakers is considered
insufficient without this help. Please note that if the NEUTRIK SPEAKON input is
used, there will be no output from these phono sockets.
Amplifier Dedicated
LFE Outputs
Phono to Phono Interconnect
(Optional Extra)
To Strata2
Line Level Input
Fig. 2
Preamp
Preamp Output
Phono to Phono Interconnect
(Optional Extra)
To Strata2
Line Level Input
From Strata2
Base Cut Output
1 or 2(See Page 9)
Power Amp Power Amp
Inputs
Fig. 3
After connecting your signal leads, connect the mains lead to Strata II and to the
mains and switch on.
R/H L/H
R/H L/H

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The first method is the preferred method where the highest possible sound quality is
demanded. It has the advantage of ensuring that Strata II receives precisely the
same signal as is being passed to your main speakers. This helps to ensure better
system integration between the two systems (your main speakers and Strata II).
This is a very important point and together with the Strata II’s Active Bass Controller
(ABC), ensures far superior system integration of the sub-bass with the main
system. So far as we are aware, REL are the only sub-bass manufacturer to take
this aspect of performance sufficiently seriously to offer the listener this level of
sophisticated control.
With Dolby AC3 equipment, the most suitable method of connecting up should use
both high and low level inputs together. This method ensures that Strata II receives
both the usual full range signal from the speaker outputs (front left and front right) to
ensure optimum integration with the front system and the sub-bass effects from the
LFE output. If there are two LFE outputs, then both could be used together for a
single Strata II. Alternatively, two Strata II’s could be used for an even greater
dynamic range and bass extension when one should be connected to front left and
rear left and the other to the front right and rear right. The individual LFE outputs
should then be connected to the appropriate Strata II Phono low level input. The
controller (processor) should then be switched to 'full range' on its control options.
SETTING UP AND RUNNING-IN
SETTING UP
Initially, test the action of the controls with the Strata II sited in any convenient
position in your listening room.
Strata II has a phase reversal switch to allow partial cancellation of the frequencies
around the crossover point between the subwoofer and your main system. Listen to
the quality of the bass with the phase switch in position 1 and then in position 2.
Choose the position which subjectively offers the tightest and cleanest bass.
Position 1 is positive phase, i.e. a positive going input signal causes a positive
pressure wave front from Strata II.
Turn the two filter controls fully clockwise (maximum bandwidth). Play some music
with a known bass content, and then adjust the gain control for similar sound levels
from your main system and your sub-woofer. Now reduce both of the filters to the
minimum position. Notice that the level of the bass has almost disappeared. This is
because these very low frequencies are not being boosted by your room. Without
the Active Bass Controller (ABC) you would never be able to hear them properly in
your room. Increase the gain control until this deep bass is heard. Slowly increase
the coarse control, one step at a time. If one position appears to be too much,
reduce the control to the lower setting, then increase the fine control, one notch at a
time, until there is a good match between the two systems. It may be necessary,
also, to re-adjust the gain control. With listening experience, it will soon be obvious
which setting sounds best in your room and for your system. One other major
benefit of a REL sub-woofer is that, if you move house or change your system, you
can immediately re-adjust the controls for the best sound again.
It may take several days before you are completely satisfied that you have found the

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final best setting. Your acuteness and ability to perceive very subtle differences will
improve over these days, possibly because you may not have previously had the
opportunity to hear very deep bass in your room. If the bass sounds too prominent,
simply reduce one of the filter controls a notch. If there is a "hole", increase one of
the filter controls until it is filled in.
It is often surprising just how much effect the room is having on the bass response.
Sometimes, even quite small loudspeakers appear to need very low settings of
ABC. If this is the case, accept it and feel pleased that your stereo imaging extends
down so far. It is always better to try and set up for a subtle. rather than an
overblown effect if possible. However, personal taste is the over-riding factor here. If
it sounds right to your ears, it is right.
REL sub-woofers are, so far as we know, the only available sub-woofers that
attempt to address the problems of very deep bass reproduction and matching in
any sized room. Until now there has been very little if any attempt by any
loudspeaker manufacturer to help people, particularly those with smaller or
"difficult" rooms, to obtain truly satisfactory loudspeaker/room matching in the bass.
Strata II is designed as a true sub-bass loudspeaker. It is designed to reproduce
those exceptionally deep notes that are felt, rather than heard. This it will attempt to
do at whatever volume you set on the gain control on its panel. If set too high, the
cone will simply run out of movement with the lowest notes, causing a "crack" to be
heard. If this warning is not heeded and the unit is continuously played in this
manner, permanent damage will be done to the driver. This damage is NOT covered
by Warranty. Always try and adjust for a seamless integration with your main
loudspeakers. This will ensure correct settings and minimise the risk of driver
damage.
Strata II is non-critical of positioning. For the loudest and deepest bass, however, it
is best positioned with its back to the wall, or even in a corner.
RUNNING-IN
Care taken over the running-in will be rewarded with many years of pleasurable use.
Both the electronics and the drive units will benefit from an initial period of carefully
controlled use. During this period, permanent damage can be sustained by running
the unit at too high a volume setting. Conversely, by taking a little care over this
initial period (about 12 hours of use), a longer life with a higher potential eventual
performance is assured.
CARE OF YOUR STRATA II
The high quality finish of Strata II is easily cared for by the occasional wipe over with
a damp cloth. Alternatively, a soft bristled brush may be used to sweep off any dust
which faIls on the surface. If objects are placed upon the top of the unit, it is
advisable to use a small mat to protect the surface and to avoid the risk of any
rattles.
Everything about Strata II has been designed and engineered to last a lifetime.

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SOME DO'S AND DON'TS
1. Always protect the sub-woofer from getting wet.
2. Always ensure that the panel is correctly earthed via the three-core mains cable.
It is not sufficient to rely upon the earth being made via the signal ground.
3. If the mains lead is lengthened (or shortened), make absolutely certain that the
wires are correctly terminated before switching on.
4. In the unlikely event of a fuse failure, always replace the fuse with an identical
one, with the same rating and characteristics. Replacements are available from
your supplier.
5. Do not attempt to remove the panel from the enclosure. All Warranties
automatically become void if the seals are broken.
6. Never try to remove the drive unit from the enclosure. Doing so will render the
Warranty void.
7. Never try to force the switches or the gain control around further than their
natural stops.
8. Do not try to modify or "improve" the design by attempting to place objects into
the reflex port.
It is not necessary to switch off the unit between listening sessions. It will not
significantly shorten its life by leaving the unit on. On the other hand, neither will it
harm the sound quality if it is always switched off. The power consumption in the
quiescent state is negligible.
It is perfectly safe under all normal domestic circumstances as it is fully protected.

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ACTIVE BASS CONTROLLER SWITCH versus CROSSOVER
FREQUENCY
These settings determine the commencement of the upper frequency limit of the
sub-woofer. The lowest operating frequency is totally unaffected by these switches.
The four steps on the fine control are equal to one on the coarse.
SWITCH POSITIONS FREQUENCY
COARSE FINE Hz
1 1 30
1 2 33
1 3 36
1 4 39
2 1 43
2 2 47
2 3 52
2 4 57
3 1 62
3 2 67
3 3 73
3 4 80
4 1 90
4 2 100
4 3 110
4 4 120

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SPECIFICATION
TYPE REFLEX Extended response
ENCLOSURE VOLUME 40 litres
INPUT CONNECTORS Neutrik Speakon and twin
phono sockets
BASS CUT OUTPUTS:
1. Cut below 50Hz
2. Cut below 100Hz
(Both measured into 10k
ohms impedance)
GAIN CONTROL RANGE 80dB
AMPLIFIER TYPE DC coupled complementary
Mos-Fet
INPUT IMPEDANCES:
HIGH LEVEL lOOK Ohm Unbalanced
Neutrik Speakon
LOW LEVEL 10K Ohm Unbalanced, RCA
Phono
POWER OUTPUT 60 Watts R.M.S.
DRIVE UNIT Magnesium chassis, long throw
25cm
FREQUENCY RANGE 20-120Hz (upper frequency
dependent upon user settings
of ABC. Lower limit is room
dependent).
PHASING Positive, or reversed.
PHASE SWITCH POSITION 1 Gives Forward Cone Movement
For Positive Input
MAINS INPUT 220 - 240 (or 110 - 120 in certain
markets) via fused I.E.C.
standard socket.
FUSE 1 x 630mA semi-delay (220 -
240V)
1 x 1.25A semi-delay (110 -
120V) Spare fuse in sliding
drawer. Replace only with
similar type.
DIMENSIONS 416 x 518 x 3lOmm (W x H x D)
16.5 x 20.5 x 12 inches approx.
WEIGHT 18Kg, 391bs. Approx.
SUPPLIED ACCESSORIES (1) Mains lead.
(2) 10 metre Neutrik Speakon
interconnect.

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(3) Operating manual.
(4) Set of spikes.
In the interest of product development, REL Acoustics Limited reserves the
right to vary this specification without notice.
Please Note
This apparatus is designed to Class II
specification and is double insulated, therefore it
does not require to be earthed
UK OPERATION
This apparatus is supplied with a fitted three pin mains plug. A 5 amp
fuse is fitted in the plug. Should the fuse need to be replaced use a 5
amp fuse approved to ASTA or BSI 1362. Do not use without the fuse
cover in place. Replacement fuse covers are available from your
dealer.
If for any reason the plug is cut off it must NOT be re used. Please
dispose of any such plug safely. There is a danger of electric shock if
the cut-off plug is inserted into a 13A mains socket.
IMPORTANT
The wires in the mains lead are coloured in accordance with the
following code:
Green and Yellow -Earth
Blue -Neutral
Brown -Live
As the colours of the wires in the mains lead may not correspond with
the markings identifying the terminals in the replacement mains plug,
proceed as follows:
- the wire coloured Green and Yellow must be connected to the
terminal marked with the letter "E" or with the earth symbol , or
coloured Green or Green and Yellow.
- the wire coloured Blue must be connected to the terminal marked with
the letter "N" or coloured Black.

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- the wire coloured Brown must be connected to the terminal marked
with the letter “L" or coloured Red.
Revised July 9th 1997, Nov 11th 1997
This product is CE marked and has been tested to ensure it satisfies all
relevant standards for EN 50081-1 using the limits of EN 55022 class B
and IEC 801 - 4 wherever relevant.
It satisfies all tests for Conducted Emissions, Radiated Emissions,
Susceptibility and Immunity
.
It also complies with the requirements relating to class II construction
detailed in clauses 9 & 10 of BS EN 60065 1994.
It also satisfies all relevant safety tests for consumer use provided it is
used within the guidelines of this manual.