Tannoy 800 User Manual

System 800

USER MANUAL

INTRODUCTION

Thank you for purchasing the Tannoy System 800 Monitors.
This loudspeaker is a very compact, professional near-field reference monitor. Using

an advanced Dual Concentric 8” driver, if offers the advantages of the point source
operation in a very cost-effective design. The attractive octagonal shape of the
cabinet with its original rounded edge corners front panel contributes to the excellent
acoustic performance of the cabinet. Compared to its predecessor in the same
category, this product offers extended bass capability, as well as smoother overall
balance for even more transparent and fatigue-free monitoring.

Designed to be located on top of the mixing console, in a landscape format, it will
equally suit other situations where it can be used in portrait mode without any
drawback, thanks to its point source operation.

This manual is intended to provide the user with some useful advice on how to install
and use the loudspeakers, as well as more technical information about how the
system is designed, and its detailed specifications. The goal being that it will help to
get the best results, those you are expecting, from this monitoring system.

OPERATING INSTRUCTIONS

Unpacking and visual checks

To get the speakers out of the carton without damage open the end flaps fully and
bend them right back (remember there are packed in pairs). Turn the package
upside-down on the floor and lift the carton vertically up to leave the speakers resting
on their packing tray.

Inspect each speaker for signs of transit damage. In the unlikely event of this having
occurred inform the carrier and the supplier. Keep all the packaging if damage has
occurred as this will show evidence of excessive handling forces. It is also a good
idea to keep the carton if possible for future transportation.

Preliminary recommendation

Initially we would like to give a word of warning on high sound levels, which these
speakers are capable of generating over sustained periods of time. Levels over 95
dB for 8 hours per day will eventually cause permanent hearing loss. Because
Tannoy Monitors have very low levels of time, amplitude and frequency distortion it
is not always obvious that the sound level is high while working with them.

For continuous exposure we recommend the occasional use of a sound level meter
capable of integrating the sound level over a period of exposure according to noise
control standards. This should be used just to check that noise levels are always
within safety limits.

Installing and connecting the loudspeakers.

When choosing a suitable location for the monitors, bear in mind that the physical
mounting of loudspeakers can have a large influence on performance. For best
results the monitors should be mounted on a rigid structure, supported on four pads
making contacts with the laminated panel. The use of soft pads (rubber, Sorbothane,
etc..) is recommended.

When used in the landscape orientation, we recommend location of the monitors so
that the drive units are toed inwards, with their axes oriented towards the listening
position. The distance between the two speakers should be about 1.5 to 2 metres,
depending on the monitoring position. The distance between the monitoring position
and each speaker should be slightly greater than the distance between the speakers.
If the speakers are placed too close to each other the full stereo image may not
develop, on the other hand if you place them too far apart you will notice an audible
hole in the middle of the stereo image.

Ensure that the console position does not obscure the direct sound radiation from the
Dual Concentric drive unit when sitting down. The engineer and producer should
have a clear, uninterrupted view of the monitor loudspeakers.

Connection to the amplifier is made by means of a pair of banana sockets, located
on the termination panel at the back of the speakers. When connecting the speakers
it is essential that consistent polarity is observed. The red terminal on the
loudspeaker must be connected to the red or positive terminal on the power
amplifier, and the black terminal on the loudspeaker must be connected to the black,
negative or ground terminal of the power amplifier.

The types of cable used to connect the speakers to the power amplifier will
marginally affect the sound. The cross-section area of the cable should be large
enough not to affect the damping factor, and generally a cable of 2.5 mm², or
greater, cross-section can be recommended.

Before connecting the amplifier and the monitors, it is advisable to ensure that there
is no signal present either by turning amplifiers gain down or by setting the output
faders.

Power amplifiers.

The power amplifier should be reasonably well matched in power to the power rating
of the speakers. A recommended range of power can be found in the specifications
(at the end of this manual). The use of a powerful amplifier (i.e. the higher figure of
the specified power range) provides headroom which is useful especially for highly
dynamic programme materials.

Because of the high peak power handling of the Tannoy monitors, a responsible use
of even more powerful amplifiers should not represent a danger for the speakers if
the amplifiers are not overdriven.

SYSTEM DESCRIPTION AND PHILOSOPHY

A loudspeaker design naturally divides into various parts: cabinet, drive unit(s) and
crossover. The design of these parts cannot take place in isolation as they are all
interdependent.

Drive unit.

The drive unit used in the System 800 monitors is part of the latest generation of
Dual Concentric units designed by Tannoy. Among many others features, this range
of drivers incorporate a dual magnet assembly, ‘tulip’ HF waveguide and injection
moulded polypropylene LF cone.

The design of the HF waveguide has been arrived at by making extensive use of
CAD (computer aided design). It matches the acoustic source impedance at the HF
diaphragm into the acoustic environment, shaping the wavefront as it travels down
from the diaphragm ensuring equal path lengths to achieve a spherical wavefront.
Wavefront shaping begins at the diaphragm surface and, because the compression
ratio can be kept relatively low with this design, the distortions due to air non­linearities are minimised. A hyperbolic flare has been chosen for optimum low
frequency performance at the crossover point.
The HF diaphragm is made from aluminium and magnesium alloy, with optimised
shape and thickness providing rigid piston behaviour up to 25 kHz. The diaphragm
assembly is suspended by a precision moulded, inert nitrile rubber surround. Its very
narrow roll eliminates resonances below 25 kHz and provides a very stable and
consistent mounting. The roll form ensures high excursions can take place if
necessary yet provides a fatigue-indestructible assembly.
The HF voice coil assembly incorporates a high temperature copper wire chemically
bonded onto a kapton former fitting onto the outside of the HF diaphragm skirt. The
thermal power handling of the voice coil is greatly increased thanks to its ferrofluid
filled magnetic gap.

Physically, the whole HF assembly self centre mounts onto the back of the low
frequency assembly using three screws carrying with it the self-centring HF
diaphragm. Production and field service is therefore virtually foolproof and extremely
consistent.
The LF unit uses a CNC precision injection moulded polypropylene cone, terminated
by a nitrile rubber, high-compliance surround. The characteristic cone termination
impedance is matched by the surround material independently of the required
suspension compliance. The unit system compliance is provided by the rear
suspension where the best degree of mechanical control can be provided.
The shape of the LF cone has been calculated to match the HF hyperbolic
waveguide ensuring the wavefront remains spherical and perpendicular to the cone
surface throughout the propagation.
Purpose-designed trim rings are used to blend the HF wavefront into the cabinet.
This feature has been shown in our research to be the biggest single factor in
providing smooth HF radiation in Dual Concentrics.
The heart of the LF unit is the motor system comprising the magnet and voice coil.
The choice of magnet operating point parameters, air gap flux strength, voice coil
details (number of turns, resistance, winding length, diameter etc.), moving mass,
dynamic compliance and drive unit radiating area presents a very complex
mathematical problem where the solutions can take many different forms. Reaching
the correct answers is much easier if computers can be called on to assist with
solving the equations, as Tannoy do for its drivers.

Cabinet.

Aside the drive units, cabinet design plays a major role in the acoustic performance
of a speaker system. Among the problems which can contribute to the degradation of