Optimal Audio Sub User manual

Loudspeakers
Sub
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.
Optimal Audio Sub loudspeakers
are designed to extend the low
frequency performance of cuboid.
When used in conjunction with
the rest of the Optimal Audio
eco-system Sub will surprise
you with its punchy performance
and professional aesthetic. This
Quick Start Guide will help you get
your Subs rigged, positioned and
connected correctly.
Congratulations on your choice of Optimal Audio
for your latest sound system installation.
2/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
Safety
information

Sub 10 and Sub 15 are passive, low-frequency loudspeakers. Each model
consists of a single driver loaded into a compact bass-reex cabinet.
The loudspeaker has no internal electronic cross-over network and requires the
use of a DSP preset to ensure the loudspeaker is fed with an appropriate signal.
This can be achieved via external DSP processing or by using a dedicated preset
in SmartAmp 30 (Sub 10 only).
Cable channels
M8 xings
Euroblock connectors
Driver
Bass reex port
3/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
Safety
information

Sub loudspeakers are often mounted on the oor, and for good reason. Sub
10 is particularly suitable for placing discreetly under banquette seating. Floor
mounting increases low-frequency efciency due to the acoustic energy being
reected from the plane of the oor. The proximity of the cabinet to the oor,
and the fact that low-frequency sound waves are long, means that the reected
energy couples with the direct output without cancellation, adding the acoustic
power back to the wavefronts rather than it dispersing or reecting back from
more distant surfaces and causing cancellation.
Sub can be also mounted on a wall or suspended from a ceiling using the
dedicated Sub Brackets, or M8 eyebolts and steel wire rope. These are available
separately as Optimal Audio accessories. Be sure to connect up before mounting
against a wall!
It is critical that the structure to which Sub 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
eyebolt and rated safety chain or steel wire rope xed to an M8 eyebolt screwed
into one of the M8 ttings.
4/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
Safety
information

To get the best out of your Optimal Audio loudspeaker system, it’s well worth
considering how best to align Subs with your Cuboids, depending on the relative
placement of the sub-bass and higher frequency elements of the system.
If you are able to deploy Sub and Cuboid in close proximity to each other, this is
the best possible option as they essentially work together as one speaker - Sub
extending the low frequency response. Ensure the grilles are perfectly aligned
with each other to get the best coupling.
In many cases, Cuboid will be wall or ceiling mounted and Sub placed on the
oor. From the point of view of the ideal listening position, the two cabinets are
not the same distance away, which can lead to destructive interference at cross-
over frequency at worst, and loss of transient detail and low-frequency punch.
The system can be optimised by applying delay to the cabinet that is closer to
a given listening position, usually halfway in to the coverage area. This will
always be a compromise everywhere else, but to a much smaller degree if good
alignment is in place.
In this example, the Cuboid has been wall-mounted, and Sub is on the oor.
Decide on a Recommended Listening Position (RLP), usually halfway through the
coverage area. Measure the distance to each speaker.
Here, Cuboid is 0.9m closer than Sub.
Using the formula distance/speed of sound (334m/s @ 20 degrees C), Cuboid
should be delayed by 0.9/334 = 2.6 milliseconds.
Sub Loudspeaker alignment
5/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
Safety
information

All Sub loudspeakers are tted with Euroblock connectors. These have two pairs
of terminals.
Sub uses only 1 and 2. Pins 3 & 4 are linked to pins 1 & 2 respectively, and
provide an easy way of connecting to a further Sub. No more than two Subs
should be connected to a single amplier channel.
For connection, we recommend using a exible cable with a minimum cross-
sectional area of 2.5mm². When wiring loudspeaker cables be careful to observe
the correct polarity of the cable and connector at both ends.
Connecting Up
6/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
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 Sub 10 for example is
1000W, four times its continuous power handling of 250W.
So, give a Sub 10 250W of continuous power and you will get 121dB(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 127dB(SPL(@1m, half space)) 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 Sub speakers. A 250W amplier
will deliver 121dB(SPL) from a Sub 10 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
7/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
Safety
information

Specifications
Sub 10 Sub 15
TYPE Sub-bass loudspeaker Sub-bass loudspeaker
FREQUENCY RESPONSE
(with preset)
50Hz - 150Hz ± 3dB
-10dB @42Hz
45Hz - 150Hz ± 3dB
-10dB @40Hz
DRIVERS LF: 10” (250mm) LF: 15” (380mm)
RATED POWER 250W (AES) 1000W (peak) 500W (AES) 2000W (peak)
NOMINAL IMPEDANCE 8Ω 8Ω
SENSITIVITY (1W/1m) 97dB (half space) 102dB (half space)
MAXIMUM SPL 121dB (cont), 127dB (peak) (half space) 129dB (cont), 135dB (peak) (half space)
CROSSOVER n/a n/a
DISPERSION (-6dB) n/a n/a
ENCLOSURE Plywood Plywood
FINISH Black textured paint Black textured paint
PROTECTIVE GRILLE Perforated steel Perforated steel
CONNECTORS Euroblock type Euroblock type
PIN CONNECTIONS (INPUT) 1+ 1- 1+ 1-
FITTINGS 12 x M8, inset bolts 12 x M8, inset bolts
DIMENSIONS (W) 470mm x (H) 297mm x (D) 353mm
(W) 18.50” x (H) 11.7” x (D) 13.9”
(W) 716mm x (H) 443mm x (D) 480mm
(W) 28.19” x (H) 17.4” x (D) 18.9”
WEIGHT 12.9kg (28.4lb) 34.3kg (75.6lb)
ACCESSORIES
(available separately)
Sub bracket (pair), M8 eye bolt M8 eye bolt
8/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
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.
9/10
Sub
Loudspeakers
Loudspeakers
USER GUIDE
© 2021. Optimal Audio Group Ltd. (v1.0)
Introduction
Overview
Mounting
Alignment
Connecting up
Matching
speakers &
amps
>
<
Specications
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