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8. Positioning

When a bass loudspeaker is used in an environment with boundary surfaces, its placement
affects its frequency response. When such effects are properly understood, they can be used
to great effect in producing the desired sound quality without the aid of additional
amplification.

Consider fig (a) in the diagram below, here we see a loudspeaker in free field or anechoic
conditions. We measure its sound pressure level at a distance D, and refer to this as our
reference level, or 0 dB SPL.
If we now place a large reflective surface (i.e., a wall, ceiling or floor) next to the
loudspeaker, see fig (b), the sound that is radiated towards the boundary is reflected. As a
result, the sound pressure level can increase by as much as 3 dB (effectively doubling the
available amplifier power). The loudspeaker is radiating its power into half as much space,
this is known as half space loading. For each additional boundary the SPL can increase by
3dB. Corner placement or eighth space loading can increase a bass speaker’s efficiency by
up to 9dB.
This effect is not the same at all frequencies. Loudspeakers are only essentially
omnidirectional at low frequencies (where the wavelength is large in comparison to the
loudspeaker). At high frequencies sound radiates in a more directional manner. We can
position full range loudspeakers next to a boundary in order to boost the lower frequencies
while the highs remain unchanged.
Coupling, or placing bass cabinets together will also increase bass output.

Содержание B950

Страница 1: ...B950 USER MANUAL...

Страница 2: ...rs Cabling 4 Polarity Checking 5 Amplification Power Handling 6 Crossovers 7 Equalisation 8 Positioning 9 Dimensions 10 Performance Data 11 Technical Specifications 12 Recommended Service Parts Access...

Страница 3: ...Unpacking Every Tannoy product is carefully inspected before packing After unpacking your B950 please inspect for any exterior physical damage and save the carton and any relevant packaging materials...

Страница 4: ...larity Checking It is most important to check the polarity of the wiring before the speaker system is flown A simple method of doing this without a pulse based polarity checker for LF units is as foll...

Страница 5: ...turers amplifiers in a single installation that the 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 singl...

Страница 6: ...undary is reflected As a result the sound pressure level can increase by as much as 3 dB effectively doubling the available amplifier power The loudspeaker is radiating its power into half as much spa...

Страница 7: ...9 Dimensions B950 160 0 450 0 125 0 145 0 2 HANDLES BOTH ENDS 576 0 650 0 1110 0...

Страница 8: ...10 Performance Data...

Страница 9: ...18mm multi ply birch plywood Finish Textured black grey paint Protective Grille Perforated steel black with 50 free air flow Connectors 2 x Speakon NL4MPR IN OUT Rigging Fittings 4 x Recessed carrying...

Страница 10: ...tal loudspeaker management system HK 220 240V 13 Warranty No maintenance of the B950 loudspeaker is necessary All Tannoy professional loudspeaker products are covered by a 5 year warranty from the dat...

Страница 11: ...ted such that electromagnetic disturbances generated do not exceed levels allowing radio and telecommunications equipment and other apparatus to operate as intended and the apparatus has an adequate l...

Страница 12: ...99 Fax 44 0 1236 428230 Internet http www tannoy com TGI Tannoy 300 Gage Avenue Kitchener Ontario CANADA N2M 2C8 Telephone 519 745 1158 Fax 519 745 2364 Tannoy Nederland BV Anthonetta Kuijlstraat 19 3...

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