5
as a ‘wedge’ monitor) is reduced by using a shelving filter. In some situations the
T300 will be used close to a wall (half space loading), or in a corner (quarter space
loading). It may be beneficial to use the EQ MODE MONITOR button in these
instances if the bass frequencies sound ‘overblown’.
The PHASE INVERT push button on the sub channel inverts the polarity of the sub
bass signal. This is mainly implemented to operate the system in conjunction with
Tannoy B400 sub-bass loudspeakers (see B400 user manual).
The GROUND LIFT push button connects/disconnects between the signal ground
and the mains earth, which is linked to the chassis. Using this button may help
eliminate hum caused by ground loops created in the system.
Situated inside the TX3 on the main PCB next to the power supply is a jumper switch
JP1 which allows optimum configuration of the low frequency Hi-Pass filtering
applied to the Sub channel. The ‘45’ Hz position is intended for use with the B400,
while the ‘30 Hz’ position is intended for B950 and B475.
Figure 4. TX3 simplified block diagram.
