Tannoy B475 User Manual

B475

USER MANUAL

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CONTENTS

1. Introduction..........................................................................................................5

2. Unpacking............................................................................................................5

3. Connectors/Cabling .............................................................................................5

4. Polarity Checking.................................................................................................6

5. Amplification & Power Handling ...........................................................................6

6. Crossovers...........................................................................................................7

7. Equalisation .........................................................................................................7

8. Flying...................................................................................................................7

9. Positioning ...........................................................................................................8

10. Dimensions........................................................................................................9

11. Technical Specifications...................................................................................10

12. B475 Service Parts & Accessories...................................................................11

13. Warranty..........................................................................................................11

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1. Introduction

Thank you for purchasing Tannoy B475.
The Tannoy B475 is an 18” direct radiating bass loudspeaker system, designed for

high definition sound reinforcement at low and ultra-low frequencies. It will extend the
power bandwidth of Tannoy i/T range mid/high sound reinforcement systems to below
30Hz, making it ideal for effects in club, theatre and concert sound applications, with
ultra-low frequency enhancement and increased system headroom.

The B475 is intended for use on the ground and can also be close stacked, while the
main system is flown. This powerful loudspeaker is capable of delivering high sound
pressure levels with extremely low distortion while maintaining a uniform frequency
response throughout its dynamic range. This makes the speakers capable of
consistent intelligibility and tonal quality at any listening level.

The B475 comprises 1 × 18” high efficiency bass units housed in a heavily braced
optimally vented enclosure. Ruggedly constructed from multiple-ply hardwood, the
B475 features carrying handles, along with convenient flying points and a pole mount
socket for ground-stacked applications.

2. Unpacking

Every Tannoy B475 product is carefully inspected before packing. After unpacking
your loudspeakers, please inspect for any exterior physical damage, and save the
carton and any relevant packaging materials in case the loudspeaker again requires
packing and shipping. In the event that damage has been sustained in transit notify
your dealer immediately.

3. Connectors/Cabling

The B475 is fitted with two 4-pole Speakon™ connectors. Speakon™ has the
following advantages over EP and XLR type connectors: All terminations are
solderless; this makes life easier at the time of installation or when field servicing is
required. Contacts will accept 6 sq. mm wire with an outside diameter of up to 15 mm
and a current rating of 30 Amps.

The pins of the two Speakon™ sockets, marked input/output on the rear of the input
panel, are paralleled within the enclosure.

Tannoy has adopted the following wiring standard for B475: -

Should you encounter any problems obtaining Speakon™ connectors, please contact
Neutrik or its distributors on the following numbers: -

UK: NEUTRIK MARKETING: 01983 811 441
USA: NEUTRIK USA INC.: [phone]
For a worldwide list of distributors, please contact Neutrik directly on: ­NEUTRIK AG: [phone]

SPEAKON™

CONNECTOR

Pin 1+ Positive

Pin 1- Negative

SIGNAL

or visit their website at: http://www.neutrik.com/
Cable choice consists mainly of selecting the correct cross sectional area in relation to

the cable length and the load impedance. A small cross sectional area would increase
the cables series resistance, inducing power loss and response variations (damping
factor).

Connectors should be wired with a minimum of 2.5 sq. mm (12 gauge) cable. This will
be perfectly satisfactory under normal conditions. In the case of very long cable runs
the wire size should exceed this, refer to the following table for guidance: -

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CABLE RUN
(m)

10 2.5

25 2.5

50 2.5

100 2.5

4. Polarity Checking

It is most important to check the polarity of the wiring. A simple method of doing this
without a pulse based polarity checker for LF units is as follows: Connect two wires to
the +ve and -ve terminals of a PP3 battery. Apply the wire which is connected to the +ve
terminal of the battery to the speaker cable leg which you believe to be connected to
Pin 1+ of the speaker connector and likewise the -ve leg of the battery to Pin 1-.

If you have wired it correctly the LF drive unit will move forward, indicating the wiring is
correct. All that remains now is to connect the +ve speaker lead to the +ve terminal on
the amplifier and the ­driver moves backwards, the input connections need to be inverted.

C.S.A. OF EACH
CONDUCTOR (mm)

4.0

6.0

4.0

6.0

4.0

6.0

4.0

6.0

ve

lead to the -

CABLE
RESISTANCE ΩΩ

0.14

0.09

0.06

0.35

0.22

0.14

0.69

0.43

0.29

1.38

0.86

0.58

ve

terminal on the amplifier. If however the LF

% POWER LOSS
INTO 8ΩΩ LOAD

1.7

1.1

0.73

4.3

2.7

1.8

8.6

5.4

3.6

17.0

11.0

7.2

% POWER LOSS
INTO 4ΩΩ LOAD

3.5

2.2

1.5

8.6

5.4

3.6

17.0

11.0

7.2

35.0

22.0

14.0

If problems are encountered, inspect the cable wiring in the first instance. It should
also be noted that different amplifier manufacturers utilise different pin configurations
and polarity conventions. If you are using amplifiers from more than one
manufacturer, check the polarity at the amplifiers as well as the loudspeakers.

5. Amplification & Power Handling

As with all professional loudspeaker systems, the power handling is a function of
voice coil thermal capacity. Care should be taken to avoid running the amplifier into
clip (clipping is the end result of overdriving any amplifier). Damage to the
loudspeaker will be sustained if the amplifier is driven into clip for any extended period
of time. Headroom of at least 3dB should be allowed. When evaluating an amplifier, it
is important to take into account its behaviour under low impedance load conditions. A
loudspeaker system is highly reactive and with transient signals it can require more
current than the nominal impedance would indicate.

Generally a higher power amplifier running free of distortion will do less damage to the
loudspeaker than a lower power amplifier continually clipping. It is also worth
remembering that a high powered amplifier running at less than 90% of output power
generally sounds a lot better than a lower power amplifier running at 100%. An
amplifier with insufficient drive capability will not allow the full performance of the
loudspeaker to be realised.

It is important when using different manufacturers amplifiers in a single installation
that they have very closely matched gains, the variation should be less than +/- 0.5dB.
This precaution is important to the overall system balance when only a single
compressor/limiter or active crossover is being used with multiple cabinets; it is
therefore recommended that the same amplifiers be used throughout.

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6. Crossovers

For optimal performance the B475 has been designed to operate with Tannoy Install
or Transportable series, e.g. i12/T12, i15 and T300, where overall system control is
achieved by utilising the TDX2 system controller. The TDX2 has been factory preset
to provide the recommended cross-over points, delays and overall system balance.
Please refer to the TDX2 manual for operation. Alternatively, Tannoy TX1, TX2 and
TX3 system controllers can be used.

If you intend using an alternative loudspeaker management system (e.g. BSS™, Klark
Teknik™, XTA™ etc) please contact your distributor or visit our website,

www.tannoy.com for the correct parameter settings or refer to the recommended

crossover points in the technical specifications section of this manual.

7. Equalisation

The B475 loudspeaker is designed to need no equalisation or correction to overcome
system limitations. As a result, it will only need equalisation to compensate for difficult
acoustic environments.

Over equalisation can reduce system headroom, and introduce phase distortion
resulting in greater problems than cures. If equalisation is required then it should be
applied gently and smoothly. Violent equalisation will be detrimental to the overall
sound quality.

8. Flying

The B475 utilises convenient flying points as well as 2 MAN pullback points allowing
for ease of installation and flexibility with the highest levels of safety. As with any flying
system, safety can only be guaranteed when all precautions have been implemented
correctly. A pole mount is also provided for flying a mid/high cabinet in the air.

NOTE: The installation of this product must be carried out in conformity with
local building codes and standards. If necessary, consult your local safety
standards officer before installing any product. Alternatively, check any laws or
bylaws. Tannoy will not be held responsible for any damage caused by the
improper installation of any flying gear or loudspeaker.

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9. Positioning

When a bass loudspeaker is used in an environment with boundary surfaces, its
placement affects its frequency response. When such effects are properly
understood, they can be used to great effect in producing the desired sound quality
without the aid of additional amplification.

Consider Figure 9a in the diagram below, here we see a loudspeaker in free field or
anechoic conditions. We measure its sound pressure level at a distance D, and refer
to this as our reference level, or 0 dB SPL.

If we now place a large reflective surface (i.e., a wall, ceiling or floor) next to the
loudspeaker, see Figure 9b, the sound that is radiated towards the boundary is
reflected. As a result, the sound pressure level can increase by as much as 3 dB
(effectively doubling the available amplifier power). The loudspeaker is radiating its
power into half as much space, this is known as half space loading. For each
additional boundary the SPL can increase by 3dB. Corner placement or eighth space
(Figure 9d) loading can increase a bass speaker’s efficiency by up to 9dB.

This effect is not the same at all frequencies. Loudspeakers are only essentially omni
directional at low frequencies (where the wavelength is large in comparison to the
loudspeaker). At high frequencies sound radiates in a more directional manner. We
can position full range loudspeakers next to a boundary in order to boost the lower
frequencies while the highs remain unchanged.

Coupling, or placing bass cabinets together will also increase bass output.

Figure 9a. Free-Field Figure 9b. Half Space

Figure 9c. Quarter Space Figure 9d. Eighth Space

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10. Dimensions

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11. Technical Specifications

Frequency response (1) +/- 3dB 28Hz - 240Hz
Recommended Amplifier Power 400 - 800 Watt / 8Ω
Power Handling Average (2) Programme Peak (10ms)

300 Watt 600 Watt 1200 Watt

Sensitivity (1)

2.83 volt @ 1m 98dB 101dB (half space)
Maximum SPL (3) Average Peak

@ 1m 123dB 129dB

Impedance Nominal 8Ω

Minimum 7.8Ω

Distortion

0.1 Full Power 2nd Harmonic 3rd Harmonic
100 Hz 0.22% 0.12%
250 Hz 0.23% 0.08%

0.01 Full Power 2nd Harmonic 3rd Harmonic
100 Hz 0.17% 0.23%

250 Hz 0.21% 0.29%
Driver Complement 1 x 18” High efficiency bass unit Type 4505
Crossover Point Active: Recommended points

70-240 Hz, 24dB/octave, Linkwitz – Riley
(dependant on application)

Enclosure 168 litre, vented, 18mm multi-ply birch plywood
Finish Textured black/grey paint
Protective Grille Black Perforated Steel, with 50% free air-flow
Connectors 2 × Speakon™ NL4MP – in/out
Fittings 8 × M10 flying inserts

2 × Man pullback point
2 × recessed carrying handles
1 × pole mount socket

Dimensions 577mm (H) × 556mm (W) × 650mm (D)

22.7” (H) × 21.9” (W) × 25.6” (D)

Weight 40.0 kg (88 lbs)

NOTES: (1) Average over stated bandwidth. Measured at 1m on axis, in an anechoic chamber.

(2) Long term power handling capacity as defined in EIA standard RS - 426A.
(3) Unweighted pink noise input, measured at 1m

Tannoy operates a policy of continuous research and development. The introduction of new materials or manufacturing
methods will always equal or exceed the published specifications which Tannoy reserve the right to alter without prior notice.
Please verify the latest specifications when dealing with critical applications

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12. B475 Service Parts & Accessories

Part Number Description

7900 0599 Driver Kit Type 4505
7900 0603 Recone Kit Type 4505

8001 2190 EBS10 Eye Bolt Set M10
8000 0727 TDX2 Digital loudspeaker management system 60-250V - UK

8000 0728 TDX2 Digital loudspeaker management system 60-250V - EUR
8000 0729 TDX2 Digital loudspeaker management system 60-250V - USA

13. Warranty

No maintenance of the B475 loudspeaker is necessary.
All Tannoy professional loudspeaker products are covered by a 5-year warranty from

the date of manufacture subject to the absence of misuse, overload or accidental
damage. Claims will not be considered is the serial number has been altered or
removed. Work under warranty should only be carried out by a Tannoy Professional
dealer or service agent. This warranty in no way affects your statutory rights. For
further information please contact your dealer or distributor in your country. If you
cannot locate your distributor please contact Customer Services, Tannoy Ltd at the
address given below.

Customer Services
Tannoy Ltd.

Coatbridge
ML5 4TF
Scotland
Telephone: [phone] (National)
[phone] (International)
Fax: [phone] (National)
[phone] (International)
E-Mail: [e-mail]
Website: www.tannoy.com

DO NOT SHIP ANY PRODUCT TO TANNOY WITHOUT PREVIOUS AUTHORISATION

Our policy commits us to incorporating improvements to our products through
continuous research and development. Please confirm current specifications for
critical applications with your supplier.

EASE Data for Tannoy Professional products available on request.

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Tannoy Limited, Professional Division, Coatbridge, Strathclyde, ML5 4TF, Scotland.
Tel: [phone] Fax [phone]
e-mail: [e-mail] Website: www.tannoy.com

Tannoy / TGI North America Inc., 335 Gage Avenue, Suite 1, Kitchener, Ontario, Canada N2M 5E1.
Tel: [phone] Fax: [phone]

e-mail: [e-mail] Website: www.tannoy.com
Tannoy Nederland b.v., Anthonetta Kuijlstraat 19, 3066 GS Rotterdam.

Tel: [phone] Fax: [phone]
e-mail: [e-mail] Website: www.tannoy.nl

Tannoy is a member of the Group of Companies

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ML 27

March 2001

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