Prestige SANDRINGHAM SE, Owner'S Manual

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6
Bi-Amping
(See fig. 4)
Bi-Amping extends the principle of bi-wiring one stage further. In this connection option separate power amplifiers are
used for bass and treble signals in each loudspeaker. Four mono (or two stereo) amplifiers of the same type are required
for a stereo pair of loudspeakers. Ensure that the cable links between the loudspeaker terminals are removed and that
correct polarity is maintained throughout.
If two stereo amplifiers are used, it is recommended that one amplifier supply bass information to left and right loudspeakers
and the other, the treble information.
It is essential that the coupling link cables between the loudspeaker terminals be removed. Avoid potential damage to your
amplifier - ensure that all connections are secure and the polarity is correct in all wiring.
Grille Removal
Special acoustically transparent cloth is used in the grilles. However, for ultimate fidelity the enthusiast will find it is best
to use these loudspeakers with their grilles removed during listening.
Unscrew the grille removal knob from the rear of the cabinet, and screw into the hole in the bottom of the grille. Using
this knob, pull the bottom of the grille away from the cabinet; the grille will drop down from its upper location. Take care
not to damage the wooden lower part of the cabinet. To replace the grille engage the top of the grille into the slot in the
cabinet and push the grill into the recess. Apply slight pressure to the bottom, until the grille clicks in place.
Loudspeaker System Adjustment
(See fig. 5)
Each loudspeaker is fitted with a control panel located on the front baffle beneath the detachable grille. This high current
switch block, labelled TREBLE ENERGY, is used to compensate for the varied acoustic characteristics of listening rooms.
The control should be adjusted with the amplifier tone controls in the 'flat' or uncompensated position and each
loudspeaker should be adjusted individually. Fully rotating the amplifier balance control, to select first one loudspeaker
and then the other, is the easiest way to do this.
There are three positions provided on the energy control, which has a shelving effect over the 1.6kHz to 20kHz frequency
band. The flattest, most linear response from the loudspeaker will be obtained with the control set at the LEVEL position,
and this position should be used for initial listening tests. If the overall quality of the high frequency sound seems
too prominent the –1.5 position should be tried. If the sound appears subdued in the treble 1.5 setting may
be preferred.
Remember the change that can be made by moving the energy control from one position to another is subtle. It may
not easily be heard if the programme material has very little content in the frequency band under consideration. Choose
a well-balanced piece of music with a full spectrum of sound. The correct setting will be found when the loudspeakers
are no longer evident and only the musical performance is heard.
7
Running in
Like all loudspeakers, the drive unit in your Tannoy Sandringham SE requires a while to reach optimum performance, as
the stresses in the materials relax - especially in the suspension system. For this reason, it is beneficial to run the system
at fairly high levels at normal room temperature, for approximately 20 hours to achieve best results.
The Low Frequency Section
The low frequency section of the Dual Concentric™ driver has exceptional power handling and dynamic range. The low
frequency cone piston is produced from selected paper pulp. This is specially treated to absorb internal resonance modes
The twin roll fabric surround is also damped and shaped correctly to terminate the moving cone and provide optimum
compliance and linearity at large excursions. The cone piston is driven by a high power motor system consisting of a four-
layer coil suspended in a precision magnetic air gap. The coil is wound with a special high temperature adhesive system
and individually cured to ensure reliable operation at high peak power inputs. The shape of the low frequency cone is
arranged to provide optimum dispersion of audio frequencies at both the high and low ends of the spectrum. The cone
flare continues the high frequency horn profile to ensure a smooth transition at the crossover point.
The High Frequency Section
The high frequency driver consists of a wide dynamic range compression unit giving superb transient performance with
a smooth uncoloured response. The compression unit feeds acoustic power through a Tulip Waveguide phase compensating
device to the throat of the low frequency horn. This horn provides an acoustic impedance transformation to match the
compression unit radiation into the listening environment.
An anodised aluminium alloy diaphragm, formed by a specially developed process, produces a piston with a very high
stiffness to mass ratio. Optimum molecular grain structure gives long-term durability. A very low mass precision copper
coil provides the driving force for the diaphragm.
The response of the compression horn driver extends two full octaves below the crossover frequency to eliminate colourations
that can arise through operation over the fundamental resonance region.
Tannoy Dual Concentric Drive Unit
One of the unique advantages of the Tannoy Dual Concentric™ principle is that the low and high frequency sound
radiation is generated on the same axis. The high frequency unit is mounted behind, and concentrically with, the low
frequency unit. High frequency sound radiates from the centre of the low frequency unit through a carefully designed
high frequency exponential horn. Low and high frequencies are therefore fully integrated at source. It is this feature that
gives the Dual Concentric™ driver such unique sound reproduction qualities.
There are other significant benefits. The high frequency unit does not obstruct the low frequency unit in any way (a unique
feature when compared with other so called coaxial systems). Polar dispersion of sound is symmetrical in both horizontal
and vertical planes. By careful crossover network design the virtual acoustic sources of the high and low frequency units
can be made to occupy the same point on the axis. Therefore the total sound appears to emanate from a single point source
located slightly behind the drive unit. This means that the loudspeakers, when fed from a high quality stereo source, can
recreate a full and accurate stereo image.
™
S
andringham