Tannoy 600A user manual Safe distance for magnetic immunity

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If the source itself has a balanced output, use shielded twin conductor cable (microphone cable) connecting pin 2/T to pin 2/T, pin 3/R to pin 3/R, and pin 1/S to pin 1/S (using the shield).

If the source has an unbalanced output, a single conductor shielded cable can be used, connecting pin 2/T of the input to the “hot” signal pin of the source, while pin 3/R and pin 1/S should be linked together and connected to the source signal ground.

Controls and indicators.

The input level switch (location 5) provides a sensitivity (i.e. gain) adjustment, the top and bottom positions corresponding respectively to -10 dBu and +4 dBu nominal sensitivities. The position of the input level switches should be identical on each monitor for correct channel balance.

When set to ‘Free space’, the LF Contour facility (location 6) extends the bass response and enhances the low frequency content below 150 Hz by means of a Hi-Q 2nd order Hi-Pass filter. In the ‘Half space’ position the LF signals are unprocessed and the bottom end response remains that of a vented system i.e. a 4th order (24 dB/octave). Note that when activating the Hi-Pass filter (‘Free Space’), very low frequencies under 30 Hz will be significantly attenuated so that mechanical stress on the LF drive unit (excursion) is maintained within safe operating limits. Also, the boost applied to the signal in the ‘Free space’ position will reduce the headroom on the LF amplifier channel and therefore the maximum SPL available.

The HF Contour switch (location 7) allows adjustment of the HF level. Its operates as a shelving filter above 2 kHz with -2 or +2 dB amplitude and a 0 dB (flat) middle position. Use this facility if you feel that a flat response is not the most appropriate to the acoustical environment, and that the HF level requires adjustment.

Use close to TV screens and video monitors.

The cabinet construction incorporates metal plates which provide a degree of shielding against the magnetic field created by the drive unit. The speakers can be therefore used relatively close to TV screens without any picture distorting effect. However some precautions must be taken, depending on which side of the speaker is located close to the screen. The diagram below gives an indication of the distance required between each side of the cabinet and the screen nearby. The figures are based on an emitted stray field not exceeding 0.3 mT (300 Gauss), usually considered as a safe value. However, as magnetic sensitivity varies from one screen to another, you are strongly advised to check before making any permanent installation.

Distance required 8 cm

Distance required = 0

Distance required 15 cm

Distance required 8 cm

Figure 2. Safe distance for magnetic immunity

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Contents System 600a Contents Unpacking and visual checks IntroductionSystem 600A Rear view Safe distance for magnetic immunity Drive unit Active crossover and amplifier Cabinet finish ML5 4TF Curves System Declaration of Conformity