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/ 26
Operating
and
Service
Manual Contents
1. AN INTRODUCTION TO THE NEW TANNOY
MONITOR SERIES LOUDSPEAKERS
2. | UNPACKING AND VISUAL CHECKS
3. QUICK SET UP PROCEDURE
4. GUIDELINES FOR INSTALLATION
9.
1
Location and Support for the
Loudspeakers
Connecting the Loudspeakers
Power Amplifiers
Listening Position
Duty Rating and On-Site Servicing
SYSTEM DESCRIPTION AND PHILOSOPHY
oohene
High Frequency Drive Unit
Low Frequency Drive Unit
Crossover Network
Terminal Panel
Cabinet
The Sum of the Parts
ON-SITE SERVICING.
oonena
Cabinet Finish
Grille Removal
Drive Unit Removal
Crossover Inspection and Removal
Drive Unit Servic
Sweep Signal Testing
TECHNICAL SPECIFICATIONS
oo@aeNe
System 6 NFM Il
System 8 NFM II
System 10 DMT Il
System 12 DMT I
System 15 DMT Il
System 215 DMT I
LIST OF RECOMMENDED SERVICE PARTS
WARRANTY
System 2 NFM
System 6 NFM Il
System 8 NFM
System 8 NFM II
System 10 DMT
System 10 DMT I
System 12 DMT
System 12 DMT I
System 15 OMT
System 15 DMT I
System 215 DMT
System 218 DMT I AN INTRODUCTION TO THE NEW TANNOY
MONITOR SERIES LOUDSPEAKERS
(Of all loudspeaker manufactures in che world ‘Tannoy has the greatest number
cof loudspeakers in ws for sound production in Brcish and European studios.
‘An enotmous numberof successful recordings have been produced on Tannoy
Monitoring since te fst introduction of the Tannoy Dual Concentric loud-
speaker in the 1950s
‘A decade has now pase since the invoduction ofthe Super Red and upgrad-
cal Super Gold seris of Tannoy Monitos. During this ime they have earned
an enviable reputation a the definitive standard for UK, European,
‘Australasian and North American recorded sound production monitoring,
Butt is easy to bury the requirements of monitor loudspeakers in a mass of
superlative technical specifications and smooth sales features. The proof of suc-
cessful engineering design is expressed in the opinions of the users and
ultimately their success in producing programme material chat is commercially
and artistically welcomed by the customer.
Ikis no coincidence chat Tannoy has been instrumental inthis process since
commercial recordings frst became avaible. Tannoy engineering philosophies
have always been genuine, no nonsense, realistic and without gienick fea-
tues, We never add a feature unless it has direct benef ro the user
‘The Dual Concentrie design philosophy is world known for its precise stereo
imagery and for the ease of finding sounds within a sound stage. ‘The presenta-
tion of the sound image makes long production sessions much les fatiguing
than with other monitoring systems because the brain does not have to work as
hard correcting for acoustic anomalies inthe time and frequency domains.
‘During the last 15 years great strides have been made in che analytical under-
standing of loudspeakers. In parle, the explosion of computing power
available to physicists, electronics, acoustics and mechanical engineers has
resulted in loudspeaker design techniques advancing ata faster rate than ever
before
mnoys masiveexpetence and is highly innovative and skilled design engi-
neering cam, bas placed the company in a most enviable position. This is
reflected for the 1990s in what isa frankly exceprional—revolutionary rather
than evoluionary—range of studio monitors. nen
UNPACKING AND VISUAL CHECKS.
"To ger the speaker out ofthe carton without damage open the end flaps fully
and bend them right back. Turn the package upside-down on the floor and lift
the carton vertically up to leave the speaker resting on its packing tray. Remove
‘the packing and the protective polythene bag,
Inspect the speaker for signs of transit damage. In the unlikely event of this,
hhaving 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,
Be very careful when lifting the larger models as they are very heavy
Particles of packing material can be removed from the cabinet and grille sue-
faces with a soft brush or proprietary clothing lint remover. TON 3
QUICK SET UP PROCEDURE
Look at the connection panel on the rear panel. The input terminals are
coloured red and black. They have been factory set with the Bi-Wire selection,
device in the notmal position.
Decide whether you want coset up using normal wieing or Bi-Wiring, Ifyou
choose Bi-Wiring you will need to arrange for wo separate win-core cables
from each channel of the power amplifier to each speaker position. The bene-
fies and philosophy behind the Bi-Wirig principle are outlined in che
technical section of this manual — see Section 5.
In cither case please use cable ofa Least 25 squate millimetre (2.5 mm’) cross
sectional area.
For normal operation just check that the Bi-Wire selector isin the normal
position with the’Fanney logo on the selector block nearest the red and black
terminals, Connect the power amplifier to the terminals marked HF (high fre-
quency) observing the standard polarity conventions, red to red and black to
black. This will ensure positive acoustic polarity provided the associated elec-
tronics is suitably configured.
For Bi-Wire operation slacken off the red and black terminals sufficiently to
allow the Bi-Wire selector block to be pulled upwards o show the words "Bi-
‘Wire’ and tighten one red terminal to hold itin place. Connect one of your
‘win core cables (othe red and black terminals marked LE (low frequency) and
the other ewin core o the terminals marked HE Please make sure that poatity
is observed.
‘Acche power amplifies, connect the two twin core cables cogether, positive o
postive, negative to negative, and wire up to che power amp ourput terminals.
Be careful to get che polarity corrector either the HF units or one complete
speaker will be out of phase. Ifyou have kepe polarity red to red, black co black.
throughout the wising then the sytem will have postive acoustic poatity pro-
vided the associate clectonics is suitably configure.
“The speakers are now ready for use. Please read the technical specifications
tegarding power handling before use on amplifiers with a power output greater
than 300 watt per channel into 8 ohm (or 150 watt for System 6)—see
Section 7.
Ifyou feel char the high frequency level requires adjustment because of envi-
ronmental or commercial circumstances then the HIF link on the rear
‘connecting panel may be set. This provides a fixed increase or decrease in the
‘output of the HF unit by 1.5 dB over the range 2.5 kHz to 25 kz. Slide the
link mechanism beoween the blue terminals to give the response as shown on.
the connecting panel scene raat MOO
GUIDELINES FOR INSTALLATION
‘Ta get the best out ofthese speakers, and therefore provide the most reliable
commercial results, attention should be paid to a few fundamental faces which
wwe have confirmed during development of these speakers
Initially we would ike to give a word of warning on high sound levels, which
these speakers are capable of generating over sustained periods. Hearing dam-
age is caused by high sound levels sustained for long periods of ime, 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 fequen-
cy distortion its not always obvious that the sound level is high while working
with them.
For continuous exposure we tecommend the occasional use of a noise doseme-
ter capable of integrating the sound level and the period of exposure according,
to noise control standards. This should be used just to check that noise expo-
sae levels are always wichin safery limits
‘The major factors which you should consider when planning a speaker instl-
lation using Tannoy Monitors (or anyone else's monitos) can be summarised
— physical location and mechanical mounting or support structure
for the speakers
— connections from power amplifier to speakers
— ype of power amplifier, power rating and configuration
— duty atin ofthe speakers and consequently the depth of on
site servicing requirements.
‘The physical mounting of loudspeakers provides the single largest influence in
performance, For best results che Tannoy Monitors must be mounted on a rigid
structure, supported on four pads making contact with the laminated panel
Location and Support for
the Loudspeakers
TThe natute ofthe support will subtly change the sound quality. Using.a sharp
poine contact (very high pressure over a small area) will educe the interaction
‘of the low frequencies with dificult room acoustics over che 50 to 150 He fe
‘quency band and wil give a generally brighter sound presentation.
‘Using sot pads, of say rubber or Sorbothane, will produce a warmer sound
swith more energy in the 100 to 200 He area and a slightly more subdued cre-
ble quality. We recommend using pads of Bostik Blu-Tick™ of about 10 mm
in diameter for optimum results.
Tannay Monitors canbe wall oft) mounted but make sure that he font Connecting the
pane ssh o slightly proud ofthe wall urfice by 10 to 15 mm. They muse
not be recessed into a wall cavity because of diffraction effects which will smear Loudspeakers
the time response, With this method of mounting che comments made above
regarding the support ofthe speaker on points o pad il apy
“Thee wo pins arable when conning the spe tthe power
amplifiers:
— use ONE normal swin cable with the Bi-Wire selector on the
rear panel sec co NORMAL. ooo
SECTION @
— + use TWO win cables with the Bi-Wie selector on the rear
pane se to BI-WIRE.
‘When using the normal connections with one twin-core cable, connect the
‘cable to the terminals marked HE This gives marginally beter sound quality
han when using the LF reminals
BicWire operation gives significantly bere sound quality for « modest outlay
in extra speaker cables, B-Wiring allows high frequency and low frequency
electrical currents to be split between two cables and therefore complex reverse
potential differences across the cables (due to resistive losses and reactive com-
ponents) do noe interact.
[Remember that with dynamic ranges of 80 dB to 100 dB in the recording
process the high frequency currents necesary for correct reproduction of a
sound wavefront may be around 60 dB or more down from the low frequency
‘custens, At these levels the potential diference across the LF cable may easly
swamp the HF signal i the region at crossover unless Bi-Wiring is used,
‘The Bi-Wiring principal also continues the wiring philosophy within the
crossover of all Tannoy speakers in that all earthing points should be star wired
to the source terminal to prevent common earth paths.
“The eypes of cable used to connect the speakers to the power amplifier will
‘marginally fle che sound whether in normal or Bi-Wize mode. There will be
‘more differences between cables of les than 2.5 mm? area in the normal mode
and so we recommend cables equal to or greater than 2,5mam" together with
Bi-Wite operation for best results
Icis worth experimenting with very pure oxygen-tee or large crystal cables as
these can resolve fine detail which would otherwise be missed. If these types of
cable are used then the cross-sectional area specification referred to above need
snot apply ily.
Tannoy does not recommend the use of certain plated or coaxial cables since
theie high capacitance can lead to instability and oscillation in some power
amplifiers rogether with some loss of high frequency definition.
“The Tannoy Monior rage will accommodate connection by 4 mm banana or
spade connectors
‘When connecting the speakers ie 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 connected to the black, negative or ground terminal ofthe power
amplifier,
"The power amplifier should be reasonably well matched in power to the power
rating ofthe speakers. Tannoy Monitors are very elcient and it can be tempt-
ing to economise on the sizeof power amplifier. However, for che comect
resolution of fine detail and dynamics the power amplifier should have suf
cient voltage swing which usually means a higher power output specification of
say greater than 150 wat.
Power Amplifiers
“The power specification ofthe speakers has been measured on a continuous
bass using well documented industry principles. The recommended use of a
high power amplifier for sound quality reasons assumes that che speaker will
not be subjected co the full lipped output ofthe amplifier over a sustained
period of time, As with all monior speakers most of the power ftom the amplificr is dissipated inside the speaker as heat. Tannoy monitors are designed
to withstand peak overload conditions without damage bat sustained overload
or waveform clipping will duce ther serviceable life considerably.
“There isthe option, when using the speakers in the Bi-Wire mode, to operate
swith two separate power amplifiers in what is known asa‘Bi-Amp’ configura-
tion. This gives addtional benefits over Bi-Wiring in that the LF and HF
sections are completely separated from each other.
If this mode is chosen then i is absoluely essential that the power amplifies
are all of exacly the same specification. Although the HE section ofthe loud
speaker does not need such high power delivery as the LF section, ie needs just,
as much instantaneous voltage swing to deliver the dynamic range.
‘Aaddivionally ts essential that che phase elationships across the audio band
are preserved and therefore if bi-amp driving is chosen dential power ampli
fiers are required,
“The power output performance ofthe Tannoy Monitor is directly related to
the power amplifier output. The conversion of electrical power from the
amplifier into sound energy is proportional to the sensitivity specification of
the Monitor, Please read the fll echnical specification for details.
For bese results in dynamic range, an amplifier of noc less than 150 watt per
channel should be used on System 6, 8 and 10 and 300 watt per channel for
System 12, 15 and 215,
Locate the monitor so that che listening position a the console is approximate-
ly 10-15 degrees from the axis of the Dual Concentric drive unit. This will
give the optimum spread of HF information.
‘The distance berwcen the two speakers should be between 2to 4 metres,
depending on control room size. Where possible avoid mounting the speakers,
close to walls, oor or ceilings. The distance herween the monitoring postion
and each speaker should be slightly greater chan the distance between the
speakers,
Please note: ifthe speakers are placed co0 close to cach other the full stereo
‘mage may not develop, on the other hand if you place them too far apart you
will notice an audible hole in the mide of the stereo image.
Ensue thar the console position does nor obscure the direct sound radiation
from the Dual Concentric drive unie when sitting doven; the engineer and pro-
ducer should havea cleat, uninterrupted view of the monitor loudspeakers.
If che loudspeakers are used within cher rated specifications then they will pro-
vide long, reliable service. In a commercial world, however, ics often
{impossible 10 guarantee that the monitoring system will noc be abused in some
way. Tannoy monitors are designed to withstand short term overload without
damage but excessive overloads will reduce the expected life ofthe mechanical
components and crossover capacitors somewhat. Therefore its sensible to
ep spare parts for on-site service where monitor down-ti
With the correct spares in stock Tannoy mon
‘than a typical coffee break.
A lise of recommended spare parts is shown in Section 8 of this manual as first,
and second level spares.
CTION ¢
Listening Position
Duty Rating and On-site
Servicing arene
JECTION 5
High Frequency Drive
Unit
SYSTEM DESCRIPTION AND PHILOSOPHY
‘A loudspeaker design naturally splits inc various parts: lower frequency, higher
frequency, crossover network and cabinet. The design of these parts cannot
take place in isolation as they reall interdependent. However For descriptive
‘purposes we will break the total design into these parts and summatse at the
end by deseribing the complete system.
“Traditionally, Tannoy has used a single magnet driving both low frequency and
high frequency magnetic air gaps. This gives a very compact drive unit with
acoustic soutce alignment, In the new designs of Dual Concentric units the
THF unit and LP unie now have separate, dedicated magnet systems. This is
because the HF waveguide design has become so sophisticated it cannot be
made by processes suitable for magnetic Aux carrying materials.
“The HF waveguide can cherfore no longer be an integral pat ofthe LF mag-
nec stem. In splitting the magnet systems an extta degree of design freedom
allows for vety high precision casting and moulding processes together with
accurate self centring diaphragm assemblies. Both production processing and
in-field repairs can then guarantee consistent performance.
‘A new design of waveguide has been arrived at by making extensive use of
CAD (computer aided design). We call ia waveguide because there isa direct
analogy with electromagnetic radiation in that characteristic impedances must
be carfilly matched without introducing standing waves. The Tannoy HE
‘waveguide maiches the acoustic source impedance at the HF diaphragm into
the listening environment.
The waveguide shapes the wavefront as it travels down from the diaphragm
cnsuring that path lengths are equal, thatthe wavefont is perpendicular ro the
fixed surfaces and tha the waveftont i spherical. Only small ext of fractions
ofa millimetre can upset this condition and cause phase shifts in the wave-
guide, Accuracy of design and produetin ar esenil in achieving the correct,
Conditions within the waveguide.
In this way transverse modes are minimised and high frequency dispersion
maximised, Wavefront shaping begins a the diaphragm surface and, because
the compression ratio can be kept tlatvely low with this desig, the distor-
tions due to air non-linearities are minimised. A hyperbolic are has been
chosen for optimum lowe frequency performance at the crossover point.
“The HF diaphragm is a new design, The waveguide requires cota piston move-
‘ment over the operating range since any breakup modes within the diaphragm
will result in phase-shifted components at the start of the waveguide propaga-
tion. A rigid piston diaphragm operating to above 25 kHz is made from
aluminium and magnesium alloy.
[A special machine bas been designed and bil to form and extrude the diaphragen
‘with a 2mm skit This configuration gives the most gid diaphragm anl ensures
reliable handling for production and field servicing,
Aluminium is notorious dificult for adhesive working and we put the
dliaphragm thtough a special allaline etching proces followed immediately by
the build proces to ensure reliably
‘The diaphragm assembly is suspended by a precision moulded, iner nitrile
subber surround, This has been designed and tooled using high-precision,
‘numerically controlled machining techniques. Its very nartow roll eliminates resonances below 25 kHz and provides a very stable and consistent mounting,
‘The rol form ensures high excursions can take place if necessary yet provides a
fatigue-indestructible assembly.
is driven by a new design of voice coil assembly. High temper-
ide-insulated, copper-clad aluminium, rectangular ribbon
chemically bonded onto a glass-fibre former fitting onto the out.
side of the HF diaphragm skirt. Ths gives «high temperature (polyimide),
very low mass (aluminium wire, glass fibee), high rigidity (reetangular wie,
formet co outside of diaphragm skirt), high reliability (nitrile suspension, cop-
per clad aluminium) assembly.
‘Leadout materials are crucial for HIF unies and our new design incorporates
beryllium copper fat stip to eliminate fatigue breakages and prevent fusing on
‘unsupported areas under overload conditions
‘The HP diaphragm assembly is fctory mounted onto the waveguide by
newly designed high-precision production process, This ensures that the spac-
ing between diaphragm and waveguide is consistent and the whole assembly
self centres under all conditions when placed on the magnet assembly. Field
replacement is therefore extremely simple and no difficule soldering or centring
techniques are required.
‘The HIF magnet assembly uses an anisotropic barium ferrite magnet for maxi-
mum energy product (BHyay). a newly developed magnetic airgap coolant
for lowest viscosity and highest thermal rating, a copper ux stabilising ring
around the pole piece to minimise voice col inductance and control the high-
«st frequency energy, and a cavity damper to control the rer cavity compliance
beneath the diaphragm.
Physically the whole HF assembly self eenee mounts onto the back ofthe low
frequency assembly using thre screws carrying with ic the se-centting HE
siaphrag. Production and field sevice is therefore vitally foolproof and
extremely consistent.
Polassed, push-on connectors provide connection to the input signal
‘The heart of the LP unit isthe motor system comprising the magnet and voice
coil. Computer optimisation of the low frequency magnet gives linear ux
linking to the voice col using low carbon steel pole pieces and an anisotropic
barium ferrite magnet. A specially designed pure copper stabilising ring fits
‘over the outer pole where it reduces eddy current losses, lowers midrange dis-
tortion and increases thermal cooling by a massive 50 per cent. In ehis way
both power compression and reliability are considerably enhanced,
"The choice of magnet operating point parameters, air gap flux strength, voice
cil dezails (number of turns, resistance, winding length, diameter et) mi
‘mass, dynamic compliance and drive unit radiating area presents avery com-
plex mathematical problem where the solutions can take many different forms.
‘The optimum solution depends on the intended use ofthe drive uni in part
tlar cabinet systems and the expectations of the end use.
‘This isthe skill or ‘black-are’ element oF loudspeaker design. Reaching the cot-
rect answers is much easier if computers can be called on to assist with solving
the equations. Tannoy hasan in-house sofeware facility producing purpose-
‘writen programs to solve these equations in both numerical and graphic
terms.
‘The LF voice coil uses polyimide insulated, chemically bonded rectangular see-
Low Frequency Drive
Unit SECTION
‘Crossover Network
sion copper wite wound onto a high temperature aluminium former for
robustness and cliailty in thermal conductivity. A specially designed heat
barrier wound onto the end of the former protects che adhesive bond to the LF
cone from excessive temperatures
Robust, fatigue-fee leadout braid connects toa polarised, vibration-proof,
high-current terminal barrier connector.
‘The shape and materials from which the cone pistons are made reflect the opti-
risstion of drive unit co cabinet size and end use. System 6, 8, 10 and 12 LE
units use a CNC precision injection moulded polypropylene cone. System 15
and 215 have a traditional pulp cone with apex treatment and ait-dry felting
proces. For cones of this size thee is no better alternative when mass rigidity,
piston movement and natural upper roll-off characteristics are consideted.
[AIL drivers have thei cones terminated by nti rubbes,high-complinice
surrounds, The characteristic cone termination impedance is matched by the
surtound material independently ofthe required suspension compliance. The
tit system compliance is provided bythe rear suspension where the best
degree of mechanical contol can be provided
In all cases the shape of the LF cone has been calculated to match the HE
bbyperbolic waveguide ensuring the wavefront remains spherical and perpendic-
lar to the cone surface throughout the propagation
Brand new pressure die-cast chassis have been tooled forthe new range draw
jing extensively on new thinking for LF drive units, Iris importane to eliminate
trapped air cavities as these can provide unwanted compliances, upset the
chanical Q design requirements and cause unwanted acoustic colourations
because of Helmholtz resonances and reflections from the chassis surfaces
smearing the energy/time response.
“The new castings have a very open construction with vented rea suspension
features to climinate low Q cavities, improve thermal cooling and prevent
‘major reflections. Rigidity has been optimised in the axial plane to comple-
‘ment the eabinet philosophy (see later) while the front surface profile has been
designed to prevent diffraction a che cabinet surface.
‘The five sizes of chassis each have purpose-designed tim rings to blend the HE
‘wavefront into the cabinet. This feature has been shown in ous research to be
the biggest single factor in providing smooth HE radiation in Dual
Concentrics (assuring, of course, that the HIF unit is well designed in che ise
instance).
‘There ate two philosophies in designing loudspeaker crossover networks: the
jinimal and he conjugate-The minimal approach requires that the drive units
are inherently well behaved and that each section, LF and HE, require mi
‘mum equalisation to achieve a smooth flat amplitude response. The conjugate
approach requires that che drive units are accepted as they are but are well
characterised, The crossover network is then calculated to provide inherent
‘equalisation to ensure a smooth amplitude response.
"The two approaches differ in design emphasis. The minimalist designer con-
ccentrates on the drive unit design in concroling the final performance, while
‘the conjugate designer concentrates on complex electronic analysis of networks
to achieve the same measured result.
“Tannoy has always followed the minimalise philosophy as far as possible. This
is because listening trials with loudspeakers always point to those with the least crossover design complexity as being more realist, involving a)
in their reproduction. However, this makes the drive une desig
dificulcas itis much harder to control performance theough t
parameters than through the electrical crossover components. |
much greater constraints on production repeatability of proces)
methods. However, overall the resule in our belief is a betel}
In crossover networks it is vital to use che very highest quality.
series connected elements. Resin impregnated, ai cored inductors and custom
[DMT capacitors are employed for best sound qualry. DMT research showed
when a capacitor was encapsulated ina vibration absorbing material ic changed
‘both the sound texture and dynamics, Every variable ofeapacitor construction
‘was investigated and custom capacitors designed optimised for sonic peefo
‘mance and with high-purity copper leads.
Vibrations inside che cabinet can effecrthe performance of inductor coils.
‘Tests show chat reducing the vibrations reaching the inductors can havea
‘marked effect on system bass end resolution. Coils vacuum impregnated with
tesin are chosen to reduce the effets of vibration,
Internal wiring has an effect on sound quality and in the Tannoy Monitor
series custom manufactured woven wire is used to reduce induced signals for a
cleaner high frequency performance.
Air cored inductors radiate significant magnetic field which afects nearby
components. Similarly induetors can be affected by a drivers magnetic radia-
tion, For these seasons i was decided to produce a splie erosover with the
inductors mounted on the cabinet cross-brace away from the driver magnets
and other crossover components. The sound quality improvements more than
justify additional manufacturing cost.
‘The crosover nesworks in the new series use simple low order slopes (6 dB and
12 4B per octave) mainly to control che power distriburion and balance. The
‘components are of very high quality with Hard-Wiring (no printed circuit
boards) and mounted on the back ofthe terminal panel atthe rear of the cabi-
net. All components ae easily serviced in the field by removing the terminal
panel from the outside of the cabinet. There is no need co remove drive units
to gain acces
‘The terminal panel isa new design especially cooled forthe new series. The
‘option of conventional witing or Bi Wiring is available by a unique high qual-
ty gold plated sliding mechanism with lage diameter robust terminals. The
benefics of Bi-Wiring for monitoring ate easily heard where the exea pair of
cables can be accommodated
"The new terminal panel on System 12, 15 and 215 also includes a sliding link
which provides adjustment of the high frequencies on a shelving basis from 2
kz to 25 kHz with plus or minus 1.5 dB adjustment. The systems are cali
‘brated in production to be fat to within specification when set to the flat
adjustment position. All terminals and contacts are gold plated to eliminate
‘contact potentials and oxidation. The terminal panel caries the crossover
‘mounting and can be removed from the outside ofthe cabinet.
‘The cabinet provides perhaps the greatest departure from convention yet seen
in the professional markerplace. There are three major philosophies in the
design:
With well designed drive units the majority of the aberrations in the loud
speaker system are due to che cabinet. Most ofthe ieregulaities heard and
Terminal Panel measured in the higher frequency areas are due to difractions and reflections
cased by the cabinet boundaries.
‘The amount of acoustic energy transfer thatthe drive units can launch into che
listener’ space is dependent on rigid mounting since action and reaction are
‘equal and opposite. When the displacements ofthe HF diaphragm are caleu-
lated for sound levels in the region of 80 to 100 dB sound pressure level, the
‘movements involved are extremely small, often fractions of a thousandth of an
inch, However tiny these displacements are they cay information that i,
requited for accuracy inthe resulting sound stage.
Testands to reason therefore that the deve unit must be held in space very
rigidly so thatthe HF diaphragm displacements are not themselves modified
by the LF displacements which have inherently mich more energy associated
with them, The obvious method of doing this is to mount the drive unt rigid-
Iy into a rigidly made cabinet. But in doing this, a new set of problems
appears.
Rig systems are characterised by high stiffness. The natural resonance of the
high cabinet stiffiness—achieved by, say, crass bracing and bracing the driver o
the rear of the cabiner—and drive uni mass, brings the natural resonance fre-
{quency into the audio band, «ypically around 100 to 200 Hz. This produces
aan objectionable colouration which can be mitigated in aural terms by some
listeners by the increase in ‘speed’ and HF clarity provided by the rigid system.
However, i is not an ideal solution.
In its new Monitors Tannoy has taken a radical approach pointed ro by mea-
sured parameter research into cabinet systems coupled with listening ests, The
‘Tannoy cabinets ate stiff but with a high level of internal damping, A very
‘complex internal bracing structure in each ofthe cabinets allows the drive unit
to be held rigidly but also ro be able to dump its resonant or reactive energy
into the lossy couplings of the cabinet. The joints between the driver and the
bracing structure have a special compound which is very stiff at high frequen-
cies but will absosb energy in the critical colouration areas,
"The cabinet panels are made from MDF but are laminated on each side ro
increase chet siffaess. However, the layer of adhesive between MDF and lami
nate acts as a lossy energy absorbent medium,
“The cabinet panels are coupled into each thet through hardwood ral tthe
corners, the disimilar materials providing further modification for any inhet-
ent reactive energy components in the cabinet caused by the dive unit.
“The rigid crossbracing structure is loaed inside the eabinet using am adhesive
system which will absorb the redundant energy from the rear of the drive unit
chassis and magnet system and yer provide the stiffness needed to allow very
fine HE resolutions from the HF une diaphragm,
In addition tothe cabinet construction the volume and port tuning have been
catflly calculated to give the bes et of parameters for monitoring loud-
speakers,
“There is fundamental relationship in loudspeakers between efiiency, cabinet
volume and lor frequency performance given that minimal amplicude varia-
tions can be tolerated (as in monivoring situations). The set of parameters that
auc arived at asa solution are inevitably a compromise and the skill of Tannoy
has always been shown tobe getting these particular parameters correct fr che
application. 2 nS ESTEE
SECTION
‘The integration of al the fescures described above is what makes the whole
loudspeaker system cven greater than the sum ofthe individual pares The Sum of the Parts
+The syle of the cabinet is no arbitrary, it has been atzived at by consider-
ing the acoustic principles of diffraction and energy storage
*+ The trim rings around the rubber surrounds are there to smooth out the
otherwise discontinuous contour to the HF wavefiont.
+ Thesmooth lines around the port tubes ensure laminas ai flow at low fre
{quencies where the air in the ports has maximum velociyy.
+ The shapes of the LF cones continue the hyperbolic waveguide for the HIF
‘energy propagation.
+ The cabinet bracing and incernal construction ensures that the HF unit can
dlliver the detail into the sound field.
*+ The application of che Differential Material Technology approach to com-
ponent behaviour under vibration and magnetic fields has lead eo custom
crossover components, custom cabling anda split crossover design being
employed.
‘The result ofall these innovations isa family of monitoting loudspeakers from
‘Tannoy; speakers which are quite remarkable in resolving the finest detail over
the whole audio spectrum,
‘The new Monitor Series loudspeakers prove that Tannoy till leads the world
in applying the science of loudspeaker design to the practical monitoring situa-
tion, These monitors ae tools to be used in producing even more arstic and
satisfying developments within ehe live and recorded sound stage. SECTION ©
Cabinet Finish
Grille Removal
Dual Concentric Driver
Removal
‘Crossover Inspection
and Removal
Drive Unit Servicing
ON-SITE SERVICING
‘The cabinet is finished in a high impact resistant, texture paint. To remove
marks and scuffs use a medium soft brush. necessary, lite warm water and,
dcergent can be used but under no circumstances use a solvent or abrasive
‘leaner. The surface will change colour when wee but will teturn to normal
shen dey.
For touch-up of paint chips contact your local Tannoy Service Agent for mate-
tials and guidance.
“The gle cloth may be brushed to emove dust and partces and may be
washed in warm soapy water if necessary. Do not soak the gil frame or dry
under artificial heat othe grille may ewist out of shape
“The grille i held by plate split dowels located inthe grill frame which fic
into rubber lined holes in the fon panel. To remove the grill pull any comer
‘until the gil fame can be eased away evenly. Do not pull shasply from only
fone corner as there is risk of che grille being twisted out of shape.
Lay the cabinet on its back taking care to protect the terminals and the rear
surface. Remove the four hexagonal socket headed bolts and set aside, Ease the
driver from the front ofthe cabinet taking care not co mark the front surface,
‘Use a piece of stout cardboard o lever against if necessary. The diver wil yield
to constant tension asthe special mass damping compound between the mag
net and the internal cabinet bracing releases. Remove the driver, note the
polarity ofthe intemal connections and disconnect the internal wiring.
“Take care not to damage the moving parts of the LF drives.
“To refit the Dual Concent driver, connect the cables from the crossover 10
the LE and HF terminals. Locate the piece of damping macerial which was
pressed between the rear of the HF magnet and the cabinet erossbrace during
‘manufacture. Roll it into a ball and press it onto the centre of the cabinet
crossbrace.
Fic the driver into che mounting hole and maintain pressure on the frone of the
chassis unl the driver seats into the compound. Please make sure tha the
internal connecting cables are noc rapped becween the TIF unic and the eabi-
nec crossbrace, Fasten the bolts finger tight and then progresively torque them