Optimal Audio Cuboid 8 User manual

Loudspeakers
Cuboid
Loudspeaker
USER GUIDE
>

The Optimal Audio range of
compatible audio zoners, ampliers
and loudspeakers are designed to
work together simply and effectively.
Our quick start guides will take you
through the simple connection and
set up procedure.
Cuboid consists of a series of full-
range, high-powered loudspeakers
designed to deliver great sound
at an affordable price. When used
in conjunction with the rest of
the Optimal Audio eco-system
Cuboid will surprise you with its
performance, even coverage and
professional aesthetic.
This Quick Start Guide will help you
get your Cuboids rigged, positioned
and connected correctly.
Congratulations on your choice of Optimal Audio
for your latest sound system installation.
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Cuboid 8, 10, 12 and 15 are all passive, full-range, 2-way loudspeakers.
This means that they have a high frequency driver loaded on to a horn, giving
increased efciency and directivity, and a low-frequency cone driver.
The loudspeaker is fed with a full-range output from an amplier and an internal
cross-over network divides the signal between the high and low frequency
drivers.
Rotatable high frequency horn, low
frequency driver, bass reex port,
M8 xings
3/16
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Cuboid can be mounted on a wall in either portrait or landscape mode using the
appropriate wall bracket or suspended from a ceiling with the appropriate
U bracket.
The above table lists the correct wall bracket for each Cuboid model, along with
the combined weight of the loudspeaker and bracket.
It is critical that the structure to which Cuboid is to be mounted is suitable
for taking the weight of the loudspeaker/bracket assembly.
It is highly recommended that a secondary safety xing be tted. This can
be achieved using a suitable rated M8 eyebolt and rated safety chain or steel
wire rope.
Cuboid Model Wall bracket Combined weight U Bracket Combined weight Eyebolt tting
Cuboid 8 A 10.64kg A 13.0kg M8 x 16
Cuboid 10 B 17.26kg B 20.0kg M8 x 21
Cuboid 12 B 21.26kg C 25.5kg M8 x 21
Cuboid 15 C 31.35kg D 35.0kg M8 x 19
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Once loudspeaker position has been
decided, afx wall section of Wall Bracket
(A,B or C depending on Cuboid model)
securely to a suitable wall mounting point
Remove M8 xing bolts from the rear
of the loudspeaker cabinet
Position loudspeaker cabinet
section of Wall Bracket over the
four M8 mounting points and
secure with the four bolts from the
back of the cabinet
Optional Wall Bracket mounting positions
enable greater down-tilt, using the lower
four M8 bolt position, or the loudspeaker
can be mounted in landscape mode by
rotating the bracket as shown:
Wall Mounting – Portrait or Landscape
5/16
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Horizontal Fixings
Vertical Fixing
Grub Screw
Lift loudspeaker into position making sure that
the two halves of Wall Bracket line up – the
adjustable bolt sits into the two ‘U shaped’ cups
in the wall section of the bracket
Secure the assembly with the xed bolt in the
lower hole in the bracket – this provides the pivot
for angling the loudspeaker. Adjust the grub
screw to x the down-tilt angle
Once the loudspeaker is in position and you are
happy with the angle adjustments, tighten all
xings as shown to lock the cabinet in place.
Horizontal xings Vertical xings
Grub screw
6/16
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

When installing horn loaded loudspeakers, it’s worth taking a moment to
understand how the loudspeaker projects sound and how to get the best
coverage in your venue by careful aiming.
The above table lists the coverage angles of the high-frequency horns in the
Cuboid range. These gures are quoted using the centre axis of the horn as 0°
and measuring the angle off centre where the sound pressure level (SPL) drops
by 6dB. The results given reect horn symmetry, 90° = 45° horizontally off axis
both sides of centre.
These specications refer to the loudspeaker ex-factory. With the loudspeaker in
portrait, the horn is tted to deliver coverage as shown in the table above. If you
intend to mount your Cuboid in landscape mode (when suspending horizontally
from ceiling for instance), consider rotating the horn as shown in the following
images:
Speaker positioning and aiming
Cuboid Model Horizontal Vertical
Cuboid 8 90° 50°
Cuboid 10 90° 50°
Cuboid 12 80° 50°
Cuboid 15 80° 50°
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Rotating the horn
Remove horn
Replace xings
Rotate horn
Rotate cabinet
2.
4.
1.
3.
8/16
Cuboid
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

The U brackets A,B,C & D are specically designed for hanging Cuboid from a
ceiling in landscape mode. Fixing the U bracket is a simple process:
• Remove the centre M8 bolt from the top and bottom of Cuboid
• Place the U bracket over the loudspeaker and line up the holes with the centre
M8 bolt hole
• Use the supplied bolts to x the bracket to the loudspeaker
• When the angle is set, x with the supplied locking screw
The coverage specications are useful for informing where the loudspeakers
should be aimed. In any horn-loaded loudspeaker, the optimum output is the
centre axis of the horn where you have maximum level from the system. It
therefore follows that the horn axis should be aimed at the furthest point of the
audience.
Sound level however decreases by 6dB for every doubling of distance. This
means that 96dB at 5m from a loudspeaker will reduce to 90dB at 10m – a
signicant drop in energy.
Ceiling mounting using the U bracket Loudspeaker aiming
25 deg
IDEAL AIMING FOR A 50 DEGREE VERTICAL HORN
HORN AXIS AIMED AT FURTHEST POINT OF COVERAGE
-6dB AIMED AT NEAREST
POINT OF COVERAGE
-6dB REDUCED ENERGY
ON CEILING
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Cuboid
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Because of this level drop over distance, in larger rooms it’s well worth considering
additional loudspeakers to counter this effect, maintaining volume and intelligibility. In this
case, it is important that the second row of loudspeakers down the room are delayed to
match the arrival of the sound from the rst pair of speakers, as shown above.
11.40 m
IN THIS EXAMPLE THE ROOM IS TOO BIG FOR ONE
SPEAKER TO BE ABLE TO COVER RIGHT TO THE BACK.
A SECOND SPEAKER IS ADDED AT THE POINT WHERE
THE FIRST AND SECOND CROSS OVER.
THE SECOND IS DELAYED BACK TO THE FIRST USING
THE FORMULA:
distance/speed of sound (334m/s @ 20 degrees C)
IN THIS CASE:
11.4/334 = 0.033 seconds, 33 milliseconds
10/16
Cuboid
Loudspeakers
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

All Cuboid loudspeakers are tted with two standard NL4 type connectors.
These have two pairs of terminals.
Cuboid uses only pins 1+ and 1-. These are linked across the two connectors,
providing a useful link to a second loudspeaker of the same model. No more than
two Cuboids should be connected to a single amplier channel.
2+ and 2- are not connected and are not linked through.
For connection, we recommend using a exible cable with a minimum cross-
sectional area of 1.5mm²
1+
2- 1-
2+
Connecting Up
Cuboid connector viewed from rear
Cuboid uses these terminals
When wiring loudspeaker cables be careful
to observe the correct polarity of the cable
and connector at both ends.
11/16
Cuboid
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

To get the best from your loudspeakers, it’s important to make sure the amplier
you are using is up to the job. Several factors have to be considered, and it’s
worth clarifying what they mean and how they affect the performance of a
loudspeaker.
Loudspeakers tend to be quantied using Watts, but this is purely a measure
of the amount of power a loudspeaker can take at its input over time, and not
necessarily a measurement of how loud it might go.
Optimal Audio loudspeaker power handling is therefore quoted as Watts (AES)
and Watts (Peak), Peak delivering 6dB(SPL) acoustic output higher than AES
(AES2-2012 standard) and referring to the loudest transients a loudspeaker can
handle without distortion.
In Watts, this means that the peak power handling of a Cuboid 8 for example is
800W, four times its continuous power handling of 200W.
So, give a Cuboid 8 200W of continuous power and you will get 115dB(SPL)
out of it if you are standing 1m away from it. It will however be able to deliver
transient peaks in the audio signal at 121dB(SPL(@1m)) without distortion or
damage.
What this all means is that for the best performance from your loudspeaker,
make sure you have an amplier that is capable of delivering more than a
loudspeaker’s rated AES power handling ability at the nominal impedence of
the loudspeaker – 8 Ohms in the case of all Cuboid speakers. A 200W amplier
will deliver 115dB(SPL) from a Cuboid 8 and nothing more, but a more powerful
amplier will have the headroom to deliver short musical transients at higher
levels, thereby ensuring that faithful reproduction of the program material is
maintained.
Matching Speakers and Amplifiers
12/16
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Wall Bracket A (Black) WB1-B Wall bracket for Cuboid 8 (Black)
Wall Bracket B (Black) WB2-B Wall bracket for Cuboid 10 & 12 (Black)
Wall Bracket C (Black) WB3-B Wall bracket for Cuboid 15 (Black)
U Bracket A (Black) UB1-B U Bracket for Cuboid 8 (Black)
U Bracket B (Black) UB2-B U Bracket for Cuboid 10 (Black)
U Bracket C (Black) UB3-B U Bracket for Cuboid 12 (Black)
U Bracket D (Black) UB4-B U Bracket for Cuboid 15 (Black)
Accessories
13/16
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© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
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Safety
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Specifications
Cuboid 8 Cuboid 10 Cuboid 12 Cuboid 15
TYPE Two-way, full range, passive loudspeaker Two-way, full range, passive loudspeaker Two-way, full range, passive loudspeaker Two-way, full range, passive loudspeaker
FREQUENCY RESPONSE
(with preset)
90Hz - 18kHz ± 3dB
-10dB @62Hz
65Hz - 20kHz ± 3dB
-10dB @49Hz
62Hz - 20kHz ± 3dB
-10dB @47Hz
58Hz - 18kHz ± 3dB
-10dB @40Hz
DRIVERS LF: 8” (200mm), ferrite motor system
HF: 1” (25mm) exit/1” (25mm) voice coil,
HT polymer dome compression driver
LF: 10” (254mm), ferrite motor system
HF: 1” (25mm) exit/1.4” (36mm) voice coil,
polyimide dome compression driver
LF: 12” (300mm), ferrite motor system
HF: 1” (25mm) exit/1.4” (36mm) voice coil,
polyimide dome compression driver
LF: 15” (380mm), ferrite motor system
HF: 1” (25mm) exit/1.7” (44mm) voice coil,
polyimide dome compression driver
RATED POWER 200W (AES) 800W (peak) 250W (AES) 1000W (peak) 300W (AES) 1200W (peak) 500W (AES) 2000W (peak)
NOMINAL IMPEDANCE 8Ω 8Ω 8Ω 8Ω
SENSITIVITY (1W/1m) 92dB 96dB 98dB 99dB
MAXIMUM SPL 115dB (cont), 121dB (peak) 120dB (cont), 126dB (peak) 123dB (cont), 129dB (peak) 126dB (cont), 132dB (peak)
CROSSOVER 2.9kHz passive 2.8kHz passive 2.5kHz passive 2.3kHz passive
DISPERSION (-6dB) 90˚ H x 50˚ V (user-rotatable) 90˚ H x 50˚ V (user-rotatable) 80˚ H x 50˚ V (user-rotatable) 80˚ H x 50˚ V (user-rotatable)
ENCLOSURE Trapezoid wooden cabinet Trapezoid wooden cabinet Trapezoid wooden cabinet Trapezoid wooden cabinet
FINISH Black textured paint Black textured paint Black textured paint Black textured paint
PROTECTIVE GRILLE Black perforated steel with scrim cloth
backing
Black perforated steel with scrim cloth
backing
Black perforated steel with scrim cloth
backing
Black perforated steel with scrim cloth
backing
CONNECTORS 2x NL4 type 2x NL4 type 2x NL4 type 2x NL4 type
PIN CONNECTIONS (INPUT) 1+/1- 1+/1- 1+/1- 1+/1-
FITTINGS 16 x M8, inset bolts 21 x M8, inset bolts 21 x M8, inset bolts 19 x M8, inset bolts
DIMENSIONS (W) 256mm x (H) 422.5mm x
(D) 261mm
(W) 10.08” x (H) 16.63” x (D) 10.28”
(W) 322mm x (H) 524mm x
(D) 326mm
(W) 12.68” x (H) 20.63” x (D) 12.83”
(W) 360mm x (H) 575mm x
(D) 392mm
(W) 14.17” x (H) 22.64” x (D) 15.43”
(W) 426.5mm x (H) 691.5mm x
(D) 416mm
(W) 16.79” x (H) 27.22” x (D) 16.38”
WEIGHT 10kg (22.05lb) 16kg (35.27lb) 20kg (44.09lb) 28kg (61.73lb)
ACCESSORIES
(available separately)
Wall bracket A, U bracket A, M8 eye bolt Wall bracket B, U bracket B, M8 eye bolt Wall bracket B, U bracket C, M8 eye bolt Wall bracket C, U bracket D, M8 eye bolt
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

This symbol is intended to alert the user to
the presence of important operating and
maintenance (servicing) instructions in the
literature accompanying the appliance.
WARNING!
DO NOT EXPOSE THIS EQUIPMENT
TO RAIN OR MOISTURE
This symbol is intended to alert the user to the
presence of uninsulated “dangerous voltage”
within the product’s enclosure that may be of
sufcient magnitude to constitute a risk of
electric shock to persons.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
Important Safety Instructions
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation opening. Install in accordance with the
manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat registers, stoves,
or other apparatus (including ampliers) that produce heat.
9. Protect the loudspeaker cable from being walked on or pinched particularly
at plugs, convenience receptacles, and the point where they exit from the
apparatus.
10. Do not unplug the unit by pulling on the loudspeaker cable, use the plug.
11. Refer all servicing to qualied service personnel. Servicing is required when
the apparatus has been damaged in any way, such as liquid has been spilled
or objects have fallen into the apparatus, the apparatus has been exposed
to rain or moisture, does not operate normally, or has been dropped.
12. The apparatus shall not be exposed to dripping or splashing and no objects
lled with liquids, such as vases, shall be placed on the apparatus.
13. Do not remove any covers, loosen any xings or allow items to enter any
aperture.
14. Ensure the loudspeaker is mounted with appropriately sized xings of
suitable load bearing capacity
15. Always ensure a secondary safety xing is used where loudspeakers are
mounted overhead.
15/16
Cuboid
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USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.1)
Introduction
Overview
Wall mounting
Horn rotation
Ceiling
mounting
Connecting up
Matching
speakers and
amps
>
<
Safety
information

Relax, It’s Optimal Audio.
Optimal Audio Group Ltd.
Century Point, Halifax Road,
Cressex Business Park,
High Wycombe,
Buckinghamshire,
HP12 3SL
optimal-audio.co.uk