CABLE RUN

C.S.A. OF EACH

CABLE

% POWER LOSS

% POWER LOSS

(m)

CONDUCTOR (mm)

RESISTANCE Ω

INTO 8Ω LOAD

INTO 4Ω LOAD

10

2.5

0.14

1.7

3.5

 

4.0

0.09

1.1

2.2

 

6.0

0.06

0.73

1.5

25

2.5

0.35

4.3

8.6

 

4.0

0.22

2.7

5.4

 

6.0

0.14

1.8

3.6

50

2.5

0.69

8.6

17.0

 

4.0

0.43

5.4

11.0

 

6.0

0.29

3.6

7.2

100

2.5

1.38

17.0

35.0

 

4.0

0.86

11.0

22.0

 

6.0

0.58

7.2

14.0

4. Polarity Checking

It is most important to check the polarity of the wiring. A simple method of doing this without a pulse based polarity checker for LF units is as follows: Connect two wires to the +ve and -veterminals of a PP3 battery. Apply the wire which is connected to the +ve terminal of the battery to the speaker cable leg which you believe to be connected to Pin 1+ of the speaker connector and likewise the -veleg of the battery to Pin 1-.

If you have wired it correctly the LF drive unit will move forward, indicating the wiring is correct. All that remains now is to connect the +ve speaker lead to the +ve terminal on the amplifier and the -velead to the -veterminal on the amplifier. If however the LF driver moves backwards, the input connections need to be inverted.

If problems are encountered, inspect the cable wiring in the first instance. It should also be noted that different amplifier manufacturers utilise different pin configurations and polarity conventions. If you are using amplifiers from more than one manufacturer, check the polarity at the amplifiers as well as the loudspeakers.

5. Amplification & Power Handling

As with all professional loudspeaker systems, the power handling is a function of voice coil thermal capacity. Care should be taken to avoid running the amplifier into clip (clipping is the end result of overdriving any amplifier). Damage to the loudspeaker will be sustained if the amplifier is driven into clip for any extended period of time. Headroom of at least 3dB should be allowed. When evaluating an amplifier, it is important to take into account its behaviour under low impedance load conditions. A loudspeaker system is highly reactive and with transient signals it can require more current than the nominal impedance would indicate.

Generally a higher power amplifier running free of distortion will do less damage to the loudspeaker than a lower power amplifier continually clipping. It is also worth remembering that a high powered amplifier running at less than 90% of output power generally sounds a lot better than a lower power amplifier running at 100%. An amplifier with insufficient drive capability will not allow the full performance of the loudspeaker to be realised.

It is important when using different manufacturers amplifiers in a single installation that they have very closely matched gains, the variation should be less than +/- 0.5dB. This precaution is important to the overall system balance when only a single compressor/limiter or active crossover is being used with multiple cabinets; it is therefore recommended that the same amplifiers be used throughout.

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Tannoy B475 user manual 100 17.0 35.0 11.0 22.0 14.0 Polarity Checking, Amplification & Power Handling

B475 specifications

The Tannoy B475 is a high-performance loudspeaker that showcases the brand's commitment to excellence in sound reproduction. Designed primarily for professional audio applications, the B475 embodies a rich heritage of audio engineering, making it an ideal choice for musicians, sound engineers, and event organizers who demand clarity and power.

One of the defining features of the B475 is its robust construction. Built to withstand the rigors of touring and live performances, the cabinet is crafted from high-quality materials that ensure durability without compromising sound quality. The enclosure is designed to minimize resonances, allowing the speaker to deliver a clean and accurate sound across a wide frequency range.

At the heart of the B475 is Tannoy's proprietary Dual Concentric driver technology. This innovative design integrates the woofer and tweeter into a single point source, providing a coherent sound that enhances the listener's experience. The Dual Concentric design ensures that high and low frequencies are produced from the same location, resulting in improved phase coherence and a more natural soundstage.

Another significant aspect of the B475 is its exceptional power handling capabilities. With a high sensitivity rating, the speaker can efficiently convert input power into sound output, allowing it to deliver impressive levels of volume without distortion. This makes the B475 suitable for large venues where high sound pressure levels are required.

The B475 also features advanced crossover networks that are finely tuned to optimize performance across various frequencies. These crossovers ensure that each driver operates within its optimal range, resulting in a smooth frequency response and precise imaging. The use of high-quality components in the crossover design further enhances the overall sound quality.

Versatility is another hallmark of the Tannoy B475. It can be used in a variety of setups, whether as a standalone speaker, part of a larger PA system, or in combination with subwoofers for enhanced low-end response. With multiple input options, including XLR and 1/4-inch jacks, the B475 can easily integrate into different audio systems.

In summary, the Tannoy B475 stands out as a powerful and versatile loudspeaker, thanks to its rugged build, innovative Dual Concentric driver technology, and robust performance characteristics. Whether used for live sound reinforcement or studio monitoring, the B475 delivers audio quality that truly reflects Tannoy's legacy of excellence in the world of professional audio.